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  • Trouble with OpenLayers Styles.

    - by Jenny
    So, tired of always seeing the bright orange default regular polygons, I'm trying to learn to style OpenLayers. I've had some success with: var layer_style = OpenLayers.Util.extend({},OpenLayers.Feature.Vector.style['default']); layer_style.fillColor = "#000000"; layer_style.strokeColor = "#000000"; polygonLayer = new OpenLayers.Layer.Vector("PolygonLayer"); polygonLayer.style = layer_style; But sine I am drawing my polygons with DrawFeature, my style only takes effect once I've finished drawing, and seeing it snap from bright orange to grey is sort of disconcerting. So, I learned about temporary styles, and tried: var layer_style = new OpenLayers.Style({"default": {fillColor: "#000000"}, "temporary": {fillColor: "#000000"}}) polygonLayer = new OpenLayers.Layer.Vector("PolygonLayer"); polygonLayer.style = layer_style; This got me a still orange square--until I stopped drawing, when it snapped into completely opaque black. I figured maybe I had to explicitly set the fillOpacity...no dice. Even when I changed both fill colors to be pink and blue, respectively, I still saw only orange and opaque black. I've tried messing with StyleMaps, since I read that if you only add one style to a style map, it uses the default one for everything, including the temporary style. var layer_style = OpenLayers.Util.extend({}, OpenLayers.Feature.Vector.style['default']); var style_map = new OpenLayers.StyleMap(layer_style); polygonLayer = new OpenLayers.Layer.Vector("PolygonLayer"); polygonLayer.style = style_map; That got me the black opaque square, too. (Even though that layer style works when not given to a map). Passing the map to the layer itself like so: polygonLayer = new OpenLayers.Layer.Vector("PolygonLayer", style_map); Didn't get me anything at all. Orange all the way, even after drawn. polygonLayer = new OpenLayers.Layer.Vector("PolygonLayer", {styleMap: style_map}); Is a lot more succesful: Orange while drawing, translucent black with black outline when drawn. Just like when I didn't use a map. Problem is, still no temporary... So, I tried initializing my map this way: var style_map = new OpenLayers.StyleMap({"default": layer_style, "temporary": layer_style}); No opaque square, but no dice for the temporary, either... Still orange snapping to black transparent. Even if I make a new Style (layer_style2), and set temporary to that, still no luck. And no luck with setting "select" style, either. What am I doing wrong? Temporary IS for styling things that are currently being sketched, correct? Is there some other way specific to the drawFeature Controller? Edit: setting extendDefault to be true doesn't seem to help, either... var style_map = new OpenLayers.StyleMap({"default": layer_style, "temporary": layer_style}, {"extendDefault": "true"});

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  • Template inheritence c++

    - by Chris Condy
    I have made a template singleton class, I have also made a data structure that is templated. My question is; how do I make my templated data structure inherit from a singleton so you can only have one float type of this structure? I have tested both seperate and have found no problems. Code provided under... (That is the problem) template <class Type> class AbstractRManagers : public Singleton<AbstractRManagers<Type> > The problem is the code above doesn't work I get alot of errors. I cant get it to no matter what I do template a templated singleton class... I was asking for maybe advice or maybe if the code above is incorrect guidence? #ifndef SINGLETON_H #define SINGLETON_H template <class Type> class Singleton { public: virtual ~Singleton(); Singleton(); static Type* m_instance; }; template <class Type> Type* Singleton<Type>::m_instance = 0; #include "Singleton.cpp" #endif #ifndef SINGLETON_CPP #define SINGLETON_CPP #include "Singleton.h" template <class Type> Singleton<Type>::Singleton() { } template <class Type> Singleton<Type>::~Singleton() { } template <class Type> Type* Singleton<Type>::getInstance() { if(m_instance==nullptr) { m_instance = new Type; } return m_instance; } #endif #ifndef ABSTRACTRMANAGERS_H #define ABSTRACTRMANAGERS_H #include <vector> #include <map> #include <stack> #include "Singleton.h" template <class Type> class AbstractRManagers : public Singleton<AbstractRManagers<Type> > { public: virtual ~AbstractRManagers(); int insert(Type* type, std::string name); Type* remove(int i); Type* remove(std::string name); Type* get(int i); Type* getS(std::string name); int get(std::string name); int get(Type* i); bool check(std::string name); int resourceSize(); protected: private: std::vector<Type*> m_resources; std::map<std::string,int> m_map; std::stack<int> m_freePos; }; #include "AbstractRManagers.cpp" #endif #ifndef ABSTRACTRMANAGERS_CPP #define ABSTRACTRMANAGERS_CPP #include "AbstractRManagers.h" template <class Type> int AbstractRManagers<Type>::insert(Type* type, std::string name) { int i=0; if(!check(name)) { if(m_freePos.empty()) { m_resources.push_back(type); i = m_resources.size()-1; m_map[name] = i; } else { i = m_freePos.top(); m_freePos.pop(); m_resources[i] = type; m_map[name] = i; } } else i = -1; return i; } template <class Type> int AbstractRManagers<Type>::resourceSize() { return m_resources.size(); } template <class Type> bool AbstractRManagers<Type>::check(std::string name) { std::map<std::string,int>::iterator it; it = m_map.find(name); if(it==m_map.end()) return false; return true; } template <class Type> Type* AbstractRManagers<Type>::remove(std::string name) { Type* temp = m_resources[m_map[name]]; if(temp!=NULL) { std::map<std::string,int>::iterator it; it = m_map[name]; m_resources[m_map[name]] = NULL; m_freePos.push(m_map[name]); delete (*it).second; delete (*it).first; return temp; } return NULL; } template <class Type> Type* AbstractRManagers<Type>::remove(int i) { if((i < m_resources.size())&&(i > 0)) { Type* temp = m_resources[i]; m_resources[i] = NULL; m_freePos.push(i); std::map<std::string,int>::iterator it; for(it=m_map.begin();it!=m_map.end();it++) { if((*it).second == i) { delete (*it).second; delete (*it).first; return temp; } } return temp; } return NULL; } template <class Type> int AbstractRManagers<Type>::get(Type* i) { for(int i2=0;i2<m_resources.size();i2++) { if(i == m_resources[i2]) { return i2; } } return -1; } template <class Type> Type* AbstractRManagers<Type>::get(int i) { if((i < m_resources.size())&&(i >= 0)) { return m_resources[i]; } return NULL; } template <class Type> Type* AbstractRManagers<Type>::getS(std::string name) { return m_resources[m_map[name]]; } template <class Type> int AbstractRManagers<Type>::get(std::string name) { return m_map[name]; } template <class Type> AbstractRManagers<Type>::~AbstractRManagers() { } #endif #include "AbstractRManagers.h" struct b { float x; }; int main() { b* a = new b(); AbstractRManagers<b>::getInstance()->insert(a,"a"); return 0; } This program produces next errors when compiled : 1> main.cpp 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::stack<_Ty,_Container> &,const std::stack<_Ty,_Container> &)' : could not deduce template argument for 'const std::stack<_Ty,_Container> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\stack(166) : see declaration of 'std::operator <' 1> c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(124) : while compiling class template member function 'bool std::less<_Ty>::operator ()(const _Ty &,const _Ty &) const' 1> with 1> [ 1> _Ty=std::string 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\map(71) : see reference to class template instantiation 'std::less<_Ty>' being compiled 1> with 1> [ 1> _Ty=std::string 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(451) : see reference to class template instantiation 'std::_Tmap_traits<_Kty,_Ty,_Pr,_Alloc,_Mfl>' being compiled 1> with 1> [ 1> _Kty=std::string, 1> _Ty=int, 1> _Pr=std::less<std::string>, 1> _Alloc=std::allocator<std::pair<const std::string,int>>, 1> _Mfl=false 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(520) : see reference to class template instantiation 'std::_Tree_nod<_Traits>' being compiled 1> with 1> [ 1> _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::allocator<std::pair<const std::string,int>>,false> 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(659) : see reference to class template instantiation 'std::_Tree_val<_Traits>' being compiled 1> with 1> [ 1> _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::allocator<std::pair<const std::string,int>>,false> 1> ] 1> c:\program files\microsoft visual studio 10.0\vc\include\map(81) : see reference to class template instantiation 'std::_Tree<_Traits>' being compiled 1> with 1> [ 1> _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::allocator<std::pair<const std::string,int>>,false> 1> ] 1> c:\users\chris\desktop\311\ideas\idea1\idea1\abstractrmanagers.h(28) : see reference to class template instantiation 'std::map<_Kty,_Ty>' being compiled 1> with 1> [ 1> _Kty=std::string, 1> _Ty=int 1> ] 1> c:\users\chris\desktop\311\ideas\idea1\idea1\abstractrmanagers.h(30) : see reference to class template instantiation 'AbstractRManagers<Type>' being compiled 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::stack<_Ty,_Container> &,const std::stack<_Ty,_Container> &)' : could not deduce template argument for 'const std::stack<_Ty,_Container> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\stack(166) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::stack<_Ty,_Container> &,const std::stack<_Ty,_Container> &)' : could not deduce template argument for 'const std::stack<_Ty,_Container> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\stack(166) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::deque<_Ty,_Alloc> &,const std::deque<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::deque<_Ty,_Alloc> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\deque(1725) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::deque<_Ty,_Alloc> &,const std::deque<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::deque<_Ty,_Alloc> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\deque(1725) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::deque<_Ty,_Alloc> &,const std::deque<_Ty,_Alloc> &)' : could not deduce template argument for 'const std::deque<_Ty,_Alloc> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\deque(1725) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(1885) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(1885) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Tree<_Traits> &,const std::_Tree<_Traits> &)' : could not deduce template argument for 'const std::_Tree<_Traits> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xtree(1885) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::vector<_Ty,_Ax> &,const std::vector<_Ty,_Ax> &)' : could not deduce template argument for 'const std::vector<_Ty,_Ax> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\vector(1502) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::vector<_Ty,_Ax> &,const std::vector<_Ty,_Ax> &)' : could not deduce template argument for 'const std::vector<_Ty,_Ax> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\vector(1502) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::vector<_Ty,_Ax> &,const std::vector<_Ty,_Ax> &)' : could not deduce template argument for 'const std::vector<_Ty,_Ax> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\vector(1502) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::unique_ptr<_Ty,_Dx> &,const std::unique_ptr<_Ty2,_Dx2> &)' : could not deduce template argument for 'const std::unique_ptr<_Ty,_Dx> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\memory(2582) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::unique_ptr<_Ty,_Dx> &,const std::unique_ptr<_Ty2,_Dx2> &)' : could not deduce template argument for 'const std::unique_ptr<_Ty,_Dx> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\memory(2582) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::unique_ptr<_Ty,_Dx> &,const std::unique_ptr<_Ty2,_Dx2> &)' : could not deduce template argument for 'const std::unique_ptr<_Ty,_Dx> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\memory(2582) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1356) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1356) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::reverse_iterator<_RanIt> &,const std::reverse_iterator<_RanIt2> &)' : could not deduce template argument for 'const std::reverse_iterator<_RanIt> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1356) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1179) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1179) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::_Revranit<_RanIt,_Base> &,const std::_Revranit<_RanIt2,_Base2> &)' : could not deduce template argument for 'const std::_Revranit<_RanIt,_Base> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\xutility(1179) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(318) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(318) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2784: 'bool std::operator <(const std::pair<_Ty1,_Ty2> &,const std::pair<_Ty1,_Ty2> &)' : could not deduce template argument for 'const std::pair<_Ty1,_Ty2> &' from 'const std::string' 1> c:\program files\microsoft visual studio 10.0\vc\include\utility(318) : see declaration of 'std::operator <' 1>c:\program files\microsoft visual studio 10.0\vc\include\xfunctional(125): error C2676: binary '<' : 'const std::string' does not define this operator or a conversion to a type acceptable to the predefined operator ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

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  • Can my loop be optimized any more? (C++)

    - by Sagekilla
    Below is one of my inner loops that's run several thousand times, with input sizes of 20 - 1000 or more. Is there anything I can do to help squeeze any more performance out of this? I'm not looking to move this code to something like using tree codes (Barnes-Hut), but towards optimizing the actual calculations happening inside, since the same calculations occur in the Barnes-Hut algorithm. Any help is appreciated! typedef double real; struct Particle { Vector pos, vel, acc, jerk; Vector oldPos, oldVel, oldAcc, oldJerk; real mass; }; class Vector { private: real vec[3]; public: // Operators defined here }; real Gravity::interact(Particle *p, size_t numParticles) { PROFILE_FUNC(); real tau_q = 1e300; for (size_t i = 0; i < numParticles; i++) { p[i].jerk = 0; p[i].acc = 0; } for (size_t i = 0; i < numParticles; i++) { for (size_t j = i+1; j < numParticles; j++) { Vector r = p[j].pos - p[i].pos; Vector v = p[j].vel - p[i].vel; real r2 = lengthsq(r); real v2 = lengthsq(v); // Calculate inverse of |r|^3 real r3i = Constants::G * pow(r2, -1.5); // da = r / |r|^3 // dj = (v / |r|^3 - 3 * (r . v) * r / |r|^5 Vector da = r * r3i; Vector dj = (v - r * (3 * dot(r, v) / r2)) * r3i; // Calculate new acceleration and jerk p[i].acc += da * p[j].mass; p[i].jerk += dj * p[j].mass; p[j].acc -= da * p[i].mass; p[j].jerk -= dj * p[i].mass; // Collision estimation // Metric 1) tau = |r|^2 / |a(j) - a(i)| // Metric 2) tau = |r|^4 / |v|^4 real mij = p[i].mass + p[j].mass; real tau_est_q1 = r2 / (lengthsq(da) * mij * mij); real tau_est_q2 = (r2*r2) / (v2*v2); if (tau_est_q1 < tau_q) tau_q = tau_est_q1; if (tau_est_q2 < tau_q) tau_q = tau_est_q2; } } return sqrt(sqrt(tau_q)); }

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  • i5 vs. i7 processor dev laptop

    - by vector
    Greetings! I need to get a laptop for dev work ( mostly server side Java, NetBeans ) and wonder if anyone had a chance to use either the i5 or i7 based laptop? Is the i7 an overkill? ... or will the i5 handle it just fine? I'm thinking something from the HP line running Ubuntu. Thanks

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  • Event 4625 - Logon Failure - Server 2008 R2 is logging them all over the place ! How to stop the attack?

    - by user72593
    I've been monitoring failed logons to a server which is directly connected to the internet with no hardware firewall in the way...testing purposes only. Using the Server 2008 R2 firewall, I blocked access to just about everything except RDP, then I told the firewall to only allow connections to the RDP port from "MY" static IP. I tested from other locations and I am not able to login to the server unless i'm at my office. So how are people coming from Chinese IP's able to attempt logons and get logged as failures ?? Is there something i'm missing that needs to be blocked? Any help would be appreciated.

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  • Incremental PCA

    - by smichak
    Hi, Lately, I've been looking into an implementation of an incremental PCA algorithm in python - I couldn't find something that would meet my needs so I did some reading and implemented an algorithm I found in some paper. Here is the module's code - the relevant paper on which it is based is mentioned in the module's documentation. I would appreciate any feedback from people who are interested in this. Micha #!/usr/bin/env python """ Incremental PCA calculation module. Based on P.Hall, D. Marshall and R. Martin "Incremental Eigenalysis for Classification" which appeared in British Machine Vision Conference, volume 1, pages 286-295, September 1998. Principal components are updated sequentially as new observations are introduced. Each new observation (x) is projected on the eigenspace spanned by the current principal components (U) and the residual vector (r = x - U(U.T*x)) is used as a new principal component (U' = [U r]). The new principal components are then rotated by a rotation matrix (R) whose columns are the eigenvectors of the transformed covariance matrix (D=U'.T*C*U) to yield p + 1 principal components. From those, only the first p are selected. """ __author__ = "Micha Kalfon" import numpy as np _ZERO_THRESHOLD = 1e-9 # Everything below this is zero class IPCA(object): """Incremental PCA calculation object. General Parameters: m - Number of variables per observation n - Number of observations p - Dimension to which the data should be reduced """ def __init__(self, m, p): """Creates an incremental PCA object for m-dimensional observations in order to reduce them to a p-dimensional subspace. @param m: Number of variables per observation. @param p: Number of principle components. @return: An IPCA object. """ self._m = float(m) self._n = 0.0 self._p = float(p) self._mean = np.matrix(np.zeros((m , 1), dtype=np.float64)) self._covariance = np.matrix(np.zeros((m, m), dtype=np.float64)) self._eigenvectors = np.matrix(np.zeros((m, p), dtype=np.float64)) self._eigenvalues = np.matrix(np.zeros((1, p), dtype=np.float64)) def update(self, x): """Updates with a new observation vector x. @param x: Next observation as a column vector (m x 1). """ m = self._m n = self._n p = self._p mean = self._mean C = self._covariance U = self._eigenvectors E = self._eigenvalues if type(x) is not np.matrix or x.shape != (m, 1): raise TypeError('Input is not a matrix (%d, 1)' % int(m)) # Update covariance matrix and mean vector and centralize input around # new mean oldmean = mean mean = (n*mean + x) / (n + 1.0) C = (n*C + x*x.T + n*oldmean*oldmean.T - (n+1)*mean*mean.T) / (n + 1.0) x -= mean # Project new input on current p-dimensional subspace and calculate # the normalized residual vector g = U.T*x r = x - (U*g) r = (r / np.linalg.norm(r)) if not _is_zero(r) else np.zeros_like(r) # Extend the transformation matrix with the residual vector and find # the rotation matrix by solving the eigenproblem DR=RE U = np.concatenate((U, r), 1) D = U.T*C*U (E, R) = np.linalg.eigh(D) # Sort eigenvalues and eigenvectors from largest to smallest to get the # rotation matrix R sorter = list(reversed(E.argsort(0))) E = E[sorter] R = R[:,sorter] # Apply the rotation matrix U = U*R # Select only p largest eigenvectors and values and update state self._n += 1.0 self._mean = mean self._covariance = C self._eigenvectors = U[:, 0:p] self._eigenvalues = E[0:p] @property def components(self): """Returns a matrix with the current principal components as columns. """ return self._eigenvectors @property def variances(self): """Returns a list with the appropriate variance along each principal component. """ return self._eigenvalues def _is_zero(x): """Return a boolean indicating whether the given vector is a zero vector up to a threshold. """ return np.fabs(x).min() < _ZERO_THRESHOLD if __name__ == '__main__': import sys def pca_svd(X): X = X - X.mean(0).repeat(X.shape[0], 0) [_, _, V] = np.linalg.svd(X) return V N = 1000 obs = np.matrix([np.random.normal(size=10) for _ in xrange(N)]) V = pca_svd(obs) print V[0:2] pca = IPCA(obs.shape[1], 2) for i in xrange(obs.shape[0]): x = obs[i,:].transpose() pca.update(x) U = pca.components print U

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  • Google App Engine JDO how to define class fields ?

    - by Frank
    I have a class like this : import java.io.*; import java.util.*; public class Contact_Info_Entry implements Serializable { public static final long serialVersionUID=26362862L; String Contact_Id,First_Name="",Last_Name="",Company_Name="",Branch_Name="",Address_1="",Address_2="",City="",State="",Zip="",Country="",E_Mail="",Phone; int I_1,I_2; float F_1,F_2; boolean B_1,B_2; GregorianCalendar Date_1, Date_2; Vector<String> A_Vector=new Vector<String>(); public Contact_Info_Entry() { } ...... } If I want to translate it to a class for JDO, do I need to define each field by it self or can I do a group at a time ? For instance do I have to make it like this : @PersistenceCapable(identityType=IdentityType.APPLICATION) public class Contact_Info_Entry implements Serializable { @PrimaryKey @Persistent(valueStrategy=IdGeneratorStrategy.IDENTITY) private Long id; @Persistent public static final long serialVersionUID=26362862L; @Persistent String Contact_Id; @Persistent String First_Name; @Persistent String Last_Name; ...... @Persistent int I_1; @Persistent int I_2; ... @Persistent float F_1; ... @Persistent boolean B_1; @Persistent boolean B_2; @Persistent GregorianCalendar Date_1; ... @Persistent Vector<String> A_Vector=new Vector<String>(); public Contact_Info_Entry() { } ...... } Or can I do a group at a time like this : @PersistenceCapable(identityType=IdentityType.APPLICATION) public class Contact_Info_Entry implements Serializable { @PrimaryKey @Persistent(valueStrategy=IdGeneratorStrategy.IDENTITY) private Long id; @Persistent public static final long serialVersionUID=26362862L; @Persistent String Contact_Id,First_Name,Last_Name=""; ...... @Persistent int I_1=0,I_2=1; ... @Persistent float F_1; ... @Persistent boolean B_1,B_2; @Persistent GregorianCalendar Date_1; ... @Persistent Vector<String> A_Vector=new Vector<String>(); public Contact_Info_Entry() { } ...... } Or can I skip the "@Persistent" all together like this : import java.io.*; import java.util.*; @PersistenceCapable(identityType=IdentityType.APPLICATION) public class Contact_Info_Entry implements Serializable { public static final long serialVersionUID=26362862L; String Contact_Id,First_Name="",Last_Name="",Company_Name="",Branch_Name="",Address_1="",Address_2="",City="",State="",Zip="",Country="", E_Mail="",Phone; int I_1,I_2; float F_1,F_2; boolean B_1,B_2; GregorianCalendar Date_1, Date_2; Vector<String> A_Vector=new Vector<String>(); public Contact_Info_Entry() { } ...... } Which are correct ? Frank

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  • Google App Engine JDO how to define instance fields ?

    - by Frank
    I have a class like this : import java.io.*; import java.util.*; public class Contact_Info_Entry implements Serializable { public static final long serialVersionUID=26362862L; String Contact_Id,First_Name="",Last_Name="",Company_Name="",Branch_Name="",Address_1="",Address_2="",City="",State="",Zip="",Country="",E_Mail="",Phone; int I_1,I_2; float F_1,F_2; boolean B_1,B_2; GregorianCalendar Date_1, Date_2; Vector<String> A_Vector=new Vector<String>(); public Contact_Info_Entry() { } ...... } If I want to translate it to a class for JDO, do I need to define each field by it self or can I do a group at a time ? For instance do I have to make it like this : @PersistenceCapable(identityType=IdentityType.APPLICATION) public class Contact_Info_Entry implements Serializable { @PrimaryKey @Persistent(valueStrategy=IdGeneratorStrategy.IDENTITY) private Long id; @Persistent public static final long serialVersionUID=26362862L; @Persistent String Contact_Id; @Persistent String First_Name; @Persistent String Last_Name; ...... @Persistent int I_1; @Persistent int I_2; ... @Persistent float F_1; ... @Persistent boolean B_1; @Persistent boolean B_2; @Persistent GregorianCalendar Date_1; ... @Persistent Vector<String> A_Vector=new Vector<String>(); public Contact_Info_Entry() { } ...... } Or can I do a group at a time like this : @PersistenceCapable(identityType=IdentityType.APPLICATION) public class Contact_Info_Entry implements Serializable { @PrimaryKey @Persistent(valueStrategy=IdGeneratorStrategy.IDENTITY) private Long id; @Persistent public static final long serialVersionUID=26362862L; @Persistent String Contact_Id,First_Name,Last_Name=""; ...... @Persistent int I_1=0,I_2=1; ... @Persistent float F_1; ... @Persistent boolean B_1,B_2; @Persistent GregorianCalendar Date_1; ... @Persistent Vector<String> A_Vector=new Vector<String>(); public Contact_Info_Entry() { } ...... } Or can I skip the "@Persistent" all together like this : import java.io.*; import java.util.*; @PersistenceCapable(identityType=IdentityType.APPLICATION) public class Contact_Info_Entry implements Serializable { public static final long serialVersionUID=26362862L; String Contact_Id,First_Name="",Last_Name="",Company_Name="",Branch_Name="",Address_1="",Address_2="",City="",State="",Zip="",Country="", E_Mail="",Phone; int I_1,I_2; float F_1,F_2; boolean B_1,B_2; GregorianCalendar Date_1, Date_2; Vector<String> A_Vector=new Vector<String>(); public Contact_Info_Entry() { } ...... } Which are correct ? Frank

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  • ublas::bounded_vector<> being resized?

    - by n2liquid
    Now, seriously... I'll refrain from using bad words here because we're talking about the Boost fellows. It MUST be my mistake to see things this way, but I can't understand why, so I'll ask it here; maybe someone can enlighten me in this matter. Here it goes: uBLAS has this nice class template called bounded_vector<> that's used to create fixed-size vectors (or so I thought). From the Effective uBLAS wiki (http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?Effective_UBLAS): The default uBLAS vector and matrix types are of variable size. Many linear algebra problems involve vectors with fixed size. 2 and 3 elements are common in geometry! Fixed size storage (akin to C arrays) can be implemented efficiently as it does not involve the overheads (heap management) associated with dynamic storage. uBLAS implements fixed sizes by changing the underling storage of a vector/matrix to a "bounded_array" from the default "unbounded_array". Alright, this bounded_vector<> thing is used to free you from specifying the underlying storage of the vector to a bounded_array<> of the specified size. Here I ask you: doesn't it look like this bounded vector thing has fixed size to you? Well, it doesn't have. At first I felt betrayed by the wiki, but then I reconsidered the meaning of "bounded" and I think I can let it pass. But in case you, like me (I'm still uncertain), is still wondering if this makes sense, what I found out is that the bounded_vector<> actually can be resized, it may only not be greater than the size specified as template parameter. So, first off, do you think they've had a good reason not to make a real fixed<< size vector or matrix type? Do you think it's okay to "sell" this bounded -- as opposed to fixed-size -- vector to the users of my library as a "fixed-size" vector replacement, even named "Vector3" or "Vector2", like the Effective uBLAS wiki did? Do you think I should somehow implement a vector with fixed size for this purpose? If so, how? (Sorry, but I'm really new to uBLAS; just tried it today) I am developing a 3D game. Should uBLAS be used for the calculations involved in this ("hey, geometry!", per Effective uBLAS wiki)? What replacement would you suggest, if not? -- edit And just in case, yes, I've read this warning: It should be noted that this only changes the storage uBLAS uses for the vector3. uBLAS will still use all the same algorithm (which assume a variable size) to manipulate the vector3. In practice this seems to have no negative impact on speed. The above runs just as quickly as a hand crafted vector3 which does not use uBLAS. The only negative impact is that the vector3 always store a "size" member which in this case is redundant [or isn't it? I mean......]. I see it uses the same algorithm, assuming a variable size, but if an operation were to actually change its size, shouldn't it be stopped (assertion)? ublas::bounded_vector<float,3> v3; ublas::bounded_vector<float,2> v2; v3 = v2; std::cout << v3.size() << '\n'; // prints 2 Oh, come on, isn't this just plain betrayal?

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  • What am I doing wrong?, linking in C++

    - by Facon
    I'm trying to code a simple base64 encoder/decoder (to test my programming skill). I can compile it, but it doesn't link, I've this message error: C:\Documents and Settings\Facon\Escritoriog++ base64.o main.o -o prueba.exe main.o:main.cpp:(.text+0x24a): undefined reference to `Base64Encode(std::vector const&)' collect2: ld returned 1 exit status Compiler & Linker: Mingw32 3.4.5 SO: Windows XP This is my source code: base64.h: #ifndef BASE64_H #define BASE64_H #include <iostream> #include <vector> typedef unsigned char byte; std::string Base64Encode(const std::vector<byte> &array); std::vector<byte> Base64Decode(const std::string &array); #endif base64.cpp: #include "base64.h" std::string Base64Encode(std::vector<byte> &array) { const char *base64_table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; const unsigned int size = array.size(); std::string output; for (unsigned int i = 0; (i < size); i++) { if ((size - i) > 3) { output.push_back(static_cast<char>(base64_table[array[i] >> 2])); output.push_back(static_cast<char>(base64_table[((array[i++] & 0x03) << 4) | ((array[i] & 0xF0) >> 4)])); output.push_back(static_cast<char>(base64_table[((array[i++] & 0x0F) << 2) | ((array[i] & 0xC0) >> 4)])); output.push_back(static_cast<char>(base64_table[array[i] & 0x3F])); } else if ((size - i) == 3) { output.push_back(static_cast<char>(base64_table[array[i] >> 2])); output.push_back(static_cast<char>(base64_table[((array[i++] & 0x03) << 4) | ((array[i] & 0xF0) >> 4)])); output.push_back(static_cast<char>(base64_table[(array[i] & 0x0F) << 2])); output.push_back(static_cast<char>('=')); } else if ((size - i) == 2) { output.push_back(static_cast<char>(base64_table[array[i] >> 2])); output.push_back(static_cast<char>(base64_table[(array[i] & 0x03) << 4])); output.push_back('='); output.push_back('='); } } return output; } std::vector<byte> Base64Decode(const std::string &array) // TODO { const char *base64_table = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; } main.cpp: #include <iostream> #include <vector> #include "base64.h" using namespace std; int main(int argc, char *argv[]) { const char* prueba = "sure."; vector<byte> texto; string codificado; for (unsigned int i = 0; (prueba[i] != 0); i++) { texto.push_back(prueba[i]); } codificado = Base64Encode(texto); cout << codificado; return 0; } PD: Sorry for my bad knowledge of English :P

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  • Panning with the OpenGL Camera / View Matrix

    - by Pris
    I'm gonna try this again I've been trying to setup a simple camera class with OpenGL but I'm completely lost and I've made zero progress creating anything useful. I'm using modern OpenGL and the glm library for matrix math. To get the most basic thing I can think of down, I'd like to pan an arbitrarily positioned camera around. That means move it along its own Up and Side axes. Here's a picture of a randomly positioned camera looking at an object: It should be clear what the Up (Green) and Side (Red) vectors on the camera are. Even though the picture shows otherwise, assume that the Model matrix is just the identity matrix. Here's what I do to try and get it to work: Step 1: Create my View/Camera matrix (going to refer to it as the View matrix from now on) using glm::lookAt(). Step 2: Capture mouse X and Y positions. Step 3: Create a translation matrix mapping changes in the X mouse position to the camera's Side vector, and mapping changes in the Y mouse position to the camera's Up vector. I get the Side vector from the first column of the View matrix. I get the Up vector from the second column of the View matrix. Step 4: Apply the translation: viewMatrix = glm::translate(viewMatrix,translationVector); But this doesn't work. I see that the mouse movement is mapped to some kind of perpendicular axes, but they're definitely not moving as you'd expect with respect to the camera. Could someone please explain what I'm doing wrong and point me in the right direction with this camera stuff?

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  • How to fix issue with my 3D first person camera?

    - by dxCUDA
    My camera moves and rotates, but relative to the worlds origin, instead of the players. I am having difficulty rotating the camera and then translating the camera in the direction relative to the camera facing angle. I have been able to translate the camera and rotate relative to the players origin, but not then rotate and translate in the direction relative to the cameras facing direction. My goal is to have a standard FPS-style camera. float yaw, pitch, roll; D3DXMATRIX rotationMatrix; D3DXVECTOR3 Direction; D3DXMATRIX matRotAxis,matRotZ; D3DXVECTOR3 RotAxis; // Set the yaw (Y axis), pitch (X axis), and roll (Z axis) rotations in radians. pitch = m_rotationX * 0.0174532925f; yaw = m_rotationY * 0.0174532925f; roll = m_rotationZ * 0.0174532925f; up = D3DXVECTOR3(0.0f, 1.0f, 0.0f);//Create the up vector //Build eye ,lookat and rotation vectors from player input data eye = D3DXVECTOR3(m_fCameraX, m_fCameraY, m_fCameraZ); lookat = D3DXVECTOR3(m_fLookatX, m_fLookatY, m_fLookatZ); rotation = D3DXVECTOR3(m_rotationX, m_rotationY, m_rotationZ); D3DXVECTOR3 camera[3] = {eye,//Eye lookat,//LookAt up };//Up RotAxis.x = pitch; RotAxis.y = yaw; RotAxis.z = roll; D3DXVec3Normalize(&Direction, &(camera[1] - camera[0]));//Direction vector D3DXVec3Cross(&RotAxis, &Direction, &camera[2]);//Strafe vector D3DXVec3Normalize(&RotAxis, &RotAxis); // Create the rotation matrix from the yaw, pitch, and roll values. D3DXMatrixRotationYawPitchRoll(&matRotAxis, pitch,yaw, roll); //rotate direction D3DXVec3TransformCoord(&Direction,&Direction,&matRotAxis); //Translate up vector D3DXVec3TransformCoord(&camera[2], &camera[2], &matRotAxis); //Translate in the direction of player rotation D3DXVec3TransformCoord(&camera[0], &camera[0], &matRotAxis); camera[1] = Direction + camera[0];//Avoid gimble locking D3DXMatrixLookAtLH(&in_viewMatrix, &camera[0], &camera[1], &camera[2]);

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  • Getting Started with TypeScript – Classes, Static Types and Interfaces

    - by dwahlin
    I had the opportunity to speak on different JavaScript topics at DevConnections in Las Vegas this fall and heard a lot of interesting comments about JavaScript as I talked with people. The most frequent comment I heard from people was, “I guess it’s time to start learning JavaScript”. Yep – if you don’t already know JavaScript then it’s time to learn it. As HTML5 becomes more and more popular the amount of JavaScript code written will definitely increase. After all, many of the HTML5 features available in browsers have little to do with “tags” and more to do with JavaScript (web workers, web sockets, canvas, local storage, etc.). As the amount of JavaScript code being used in applications increases, it’s more important than ever to structure the code in a way that’s maintainable and easy to debug. While JavaScript patterns can certainly be used (check out my previous posts on the subject or my course on Pluralsight.com), several alternatives have come onto the scene such as CoffeeScript, Dart and TypeScript. In this post I’ll describe some of the features TypeScript offers and the benefits that they can potentially offer enterprise-scale JavaScript applications. It’s important to note that while TypeScript has several great features, it’s definitely not for everyone or every project especially given how new it is. The goal of this post isn’t to convince you to use TypeScript instead of standard JavaScript….I’m a big fan of JavaScript. Instead, I’ll present several TypeScript features and let you make the decision as to whether TypeScript is a good fit for your applications. TypeScript Overview Here’s the official definition of TypeScript from the http://typescriptlang.org site: “TypeScript is a language for application-scale JavaScript development. TypeScript is a typed superset of JavaScript that compiles to plain JavaScript. Any browser. Any host. Any OS. Open Source.” TypeScript was created by Anders Hejlsberg (the creator of the C# language) and his team at Microsoft. To sum it up, TypeScript is a new language that can be compiled to JavaScript much like alternatives such as CoffeeScript or Dart. It isn’t a stand-alone language that’s completely separate from JavaScript’s roots though. It’s a superset of JavaScript which means that standard JavaScript code can be placed in a TypeScript file (a file with a .ts extension) and used directly. That’s a very important point/feature of the language since it means you can use existing code and frameworks with TypeScript without having to do major code conversions to make it all work. Once a TypeScript file is saved it can be compiled to JavaScript using TypeScript’s tsc.exe compiler tool or by using a variety of editors/tools. TypeScript offers several key features. First, it provides built-in type support meaning that you define variables and function parameters as being “string”, “number”, “bool”, and more to avoid incorrect types being assigned to variables or passed to functions. Second, TypeScript provides a way to write modular code by directly supporting class and module definitions and it even provides support for custom interfaces that can be used to drive consistency. Finally, TypeScript integrates with several different tools such as Visual Studio, Sublime Text, Emacs, and Vi to provide syntax highlighting, code help, build support, and more depending on the editor. Find out more about editor support at http://www.typescriptlang.org/#Download. TypeScript can also be used with existing JavaScript frameworks such as Node.js, jQuery, and others and even catch type issues and provide enhanced code help. Special “declaration” files that have a d.ts extension are available for Node.js, jQuery, and other libraries out-of-the-box. Visit http://typescript.codeplex.com/SourceControl/changeset/view/fe3bc0bfce1f#samples%2fjquery%2fjquery.d.ts for an example of a jQuery TypeScript declaration file that can be used with tools such as Visual Studio 2012 to provide additional code help and ensure that a string isn’t passed to a parameter that expects a number. Although declaration files certainly aren’t required, TypeScript’s support for declaration files makes it easier to catch issues upfront while working with existing libraries such as jQuery. In the future I expect TypeScript declaration files will be released for different HTML5 APIs such as canvas, local storage, and others as well as some of the more popular JavaScript libraries and frameworks. Getting Started with TypeScript To get started learning TypeScript visit the TypeScript Playground available at http://www.typescriptlang.org. Using the playground editor you can experiment with TypeScript code, get code help as you type, and see the JavaScript that TypeScript generates once it’s compiled. Here’s an example of the TypeScript playground in action:   One of the first things that may stand out to you about the code shown above is that classes can be defined in TypeScript. This makes it easy to group related variables and functions into a container which helps tremendously with re-use and maintainability especially in enterprise-scale JavaScript applications. While you can certainly simulate classes using JavaScript patterns (note that ECMAScript 6 will support classes directly), TypeScript makes it quite easy especially if you come from an object-oriented programming background. An example of the Greeter class shown in the TypeScript Playground is shown next: class Greeter { greeting: string; constructor (message: string) { this.greeting = message; } greet() { return "Hello, " + this.greeting; } } Looking through the code you’ll notice that static types can be defined on variables and parameters such as greeting: string, that constructors can be defined, and that functions can be defined such as greet(). The ability to define static types is a key feature of TypeScript (and where its name comes from) that can help identify bugs upfront before even running the code. Many types are supported including primitive types like string, number, bool, undefined, and null as well as object literals and more complex types such as HTMLInputElement (for an <input> tag). Custom types can be defined as well. The JavaScript output by compiling the TypeScript Greeter class (using an editor like Visual Studio, Sublime Text, or the tsc.exe compiler) is shown next: var Greeter = (function () { function Greeter(message) { this.greeting = message; } Greeter.prototype.greet = function () { return "Hello, " + this.greeting; }; return Greeter; })(); Notice that the code is using JavaScript prototyping and closures to simulate a Greeter class in JavaScript. The body of the code is wrapped with a self-invoking function to take the variables and functions out of the global JavaScript scope. This is important feature that helps avoid naming collisions between variables and functions. In cases where you’d like to wrap a class in a naming container (similar to a namespace in C# or a package in Java) you can use TypeScript’s module keyword. The following code shows an example of wrapping an AcmeCorp module around the Greeter class. In order to create a new instance of Greeter the module name must now be used. This can help avoid naming collisions that may occur with the Greeter class.   module AcmeCorp { export class Greeter { greeting: string; constructor (message: string) { this.greeting = message; } greet() { return "Hello, " + this.greeting; } } } var greeter = new AcmeCorp.Greeter("world"); In addition to being able to define custom classes and modules in TypeScript, you can also take advantage of inheritance by using TypeScript’s extends keyword. The following code shows an example of using inheritance to define two report objects:   class Report { name: string; constructor (name: string) { this.name = name; } print() { alert("Report: " + this.name); } } class FinanceReport extends Report { constructor (name: string) { super(name); } print() { alert("Finance Report: " + this.name); } getLineItems() { alert("5 line items"); } } var report = new FinanceReport("Month's Sales"); report.print(); report.getLineItems();   In this example a base Report class is defined that has a variable (name), a constructor that accepts a name parameter of type string, and a function named print(). The FinanceReport class inherits from Report by using TypeScript’s extends keyword. As a result, it automatically has access to the print() function in the base class. In this example the FinanceReport overrides the base class’s print() method and adds its own. The FinanceReport class also forwards the name value it receives in the constructor to the base class using the super() call. TypeScript also supports the creation of custom interfaces when you need to provide consistency across a set of objects. The following code shows an example of an interface named Thing (from the TypeScript samples) and a class named Plane that implements the interface to drive consistency across the app. Notice that the Plane class includes intersect and normal as a result of implementing the interface.   interface Thing { intersect: (ray: Ray) => Intersection; normal: (pos: Vector) => Vector; surface: Surface; } class Plane implements Thing { normal: (pos: Vector) =>Vector; intersect: (ray: Ray) =>Intersection; constructor (norm: Vector, offset: number, public surface: Surface) { this.normal = function (pos: Vector) { return norm; } this.intersect = function (ray: Ray): Intersection { var denom = Vector.dot(norm, ray.dir); if (denom > 0) { return null; } else { var dist = (Vector.dot(norm, ray.start) + offset) / (-denom); return { thing: this, ray: ray, dist: dist }; } } } }   At first glance it doesn’t appear that the surface member is implemented in Plane but it’s actually included automatically due to the public surface: Surface parameter in the constructor. Adding public varName: Type to a constructor automatically adds a typed variable into the class without having to explicitly write the code as with normal and intersect. TypeScript has additional language features but defining static types and creating classes, modules, and interfaces are some of the key features it offers. So is TypeScript right for you and your applications? That’s a not a question that I or anyone else can answer for you. You’ll need to give it a spin to see what you think. In future posts I’ll discuss additional details about TypeScript and how it can be used with enterprise-scale JavaScript applications. In the meantime, I’m in the process of working with John Papa on a new Typescript course for Pluralsight that we hope to have out in December of 2012.

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  • Fun with Aggregates

    - by Paul White
    There are interesting things to be learned from even the simplest queries.  For example, imagine you are given the task of writing a query to list AdventureWorks product names where the product has at least one entry in the transaction history table, but fewer than ten. One possible query to meet that specification is: SELECT p.Name FROM Production.Product AS p JOIN Production.TransactionHistory AS th ON p.ProductID = th.ProductID GROUP BY p.ProductID, p.Name HAVING COUNT_BIG(*) < 10; That query correctly returns 23 rows (execution plan and data sample shown below): The execution plan looks a bit different from the written form of the query: the base tables are accessed in reverse order, and the aggregation is performed before the join.  The general idea is to read all rows from the history table, compute the count of rows grouped by ProductID, merge join the results to the Product table on ProductID, and finally filter to only return rows where the count is less than ten. This ‘fully-optimized’ plan has an estimated cost of around 0.33 units.  The reason for the quote marks there is that this plan is not quite as optimal as it could be – surely it would make sense to push the Filter down past the join too?  To answer that, let’s look at some other ways to formulate this query.  This being SQL, there are any number of ways to write logically-equivalent query specifications, so we’ll just look at a couple of interesting ones.  The first query is an attempt to reverse-engineer T-SQL from the optimized query plan shown above.  It joins the result of pre-aggregating the history table to the Product table before filtering: SELECT p.Name FROM ( SELECT th.ProductID, cnt = COUNT_BIG(*) FROM Production.TransactionHistory AS th GROUP BY th.ProductID ) AS q1 JOIN Production.Product AS p ON p.ProductID = q1.ProductID WHERE q1.cnt < 10; Perhaps a little surprisingly, we get a slightly different execution plan: The results are the same (23 rows) but this time the Filter is pushed below the join!  The optimizer chooses nested loops for the join, because the cardinality estimate for rows passing the Filter is a bit low (estimate 1 versus 23 actual), though you can force a merge join with a hint and the Filter still appears below the join.  In yet another variation, the < 10 predicate can be ‘manually pushed’ by specifying it in a HAVING clause in the “q1” sub-query instead of in the WHERE clause as written above. The reason this predicate can be pushed past the join in this query form, but not in the original formulation is simply an optimizer limitation – it does make efforts (primarily during the simplification phase) to encourage logically-equivalent query specifications to produce the same execution plan, but the implementation is not completely comprehensive. Moving on to a second example, the following query specification results from phrasing the requirement as “list the products where there exists fewer than ten correlated rows in the history table”: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) < 10 ); Unfortunately, this query produces an incorrect result (86 rows): The problem is that it lists products with no history rows, though the reasons are interesting.  The COUNT_BIG(*) in the EXISTS clause is a scalar aggregate (meaning there is no GROUP BY clause) and scalar aggregates always produce a value, even when the input is an empty set.  In the case of the COUNT aggregate, the result of aggregating the empty set is zero (the other standard aggregates produce a NULL).  To make the point really clear, let’s look at product 709, which happens to be one for which no history rows exist: -- Scalar aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709;   -- Vector aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709 GROUP BY th.ProductID; The estimated execution plans for these two statements are almost identical: You might expect the Stream Aggregate to have a Group By for the second statement, but this is not the case.  The query includes an equality comparison to a constant value (709), so all qualified rows are guaranteed to have the same value for ProductID and the Group By is optimized away. In fact there are some minor differences between the two plans (the first is auto-parameterized and qualifies for trivial plan, whereas the second is not auto-parameterized and requires cost-based optimization), but there is nothing to indicate that one is a scalar aggregate and the other is a vector aggregate.  This is something I would like to see exposed in show plan so I suggested it on Connect.  Anyway, the results of running the two queries show the difference at runtime: The scalar aggregate (no GROUP BY) returns a result of zero, whereas the vector aggregate (with a GROUP BY clause) returns nothing at all.  Returning to our EXISTS query, we could ‘fix’ it by changing the HAVING clause to reject rows where the scalar aggregate returns zero: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) BETWEEN 1 AND 9 ); The query now returns the correct 23 rows: Unfortunately, the execution plan is less efficient now – it has an estimated cost of 0.78 compared to 0.33 for the earlier plans.  Let’s try adding a redundant GROUP BY instead of changing the HAVING clause: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY th.ProductID HAVING COUNT_BIG(*) < 10 ); Not only do we now get correct results (23 rows), this is the execution plan: I like to compare that plan to quantum physics: if you don’t find it shocking, you haven’t understood it properly :)  The simple addition of a redundant GROUP BY has resulted in the EXISTS form of the query being transformed into exactly the same optimal plan we found earlier.  What’s more, in SQL Server 2008 and later, we can replace the odd-looking GROUP BY with an explicit GROUP BY on the empty set: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ); I offer that as an alternative because some people find it more intuitive (and it perhaps has more geek value too).  Whichever way you prefer, it’s rather satisfying to note that the result of the sub-query does not exist for a particular correlated value where a vector aggregate is used (the scalar COUNT aggregate always returns a value, even if zero, so it always ‘EXISTS’ regardless which ProductID is logically being evaluated). The following query forms also produce the optimal plan and correct results, so long as a vector aggregate is used (you can probably find more equivalent query forms): WHERE Clause SELECT p.Name FROM Production.Product AS p WHERE ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) < 10; APPLY SELECT p.Name FROM Production.Product AS p CROSS APPLY ( SELECT NULL FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ) AS ca (dummy); FROM Clause SELECT q1.Name FROM ( SELECT p.Name, cnt = ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) FROM Production.Product AS p ) AS q1 WHERE q1.cnt < 10; This last example uses SUM(1) instead of COUNT and does not require a vector aggregate…you should be able to work out why :) SELECT q.Name FROM ( SELECT p.Name, cnt = ( SELECT SUM(1) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID ) FROM Production.Product AS p ) AS q WHERE q.cnt < 10; The semantics of SQL aggregates are rather odd in places.  It definitely pays to get to know the rules, and to be careful to check whether your queries are using scalar or vector aggregates.  As we have seen, query plans do not show in which ‘mode’ an aggregate is running and getting it wrong can cause poor performance, wrong results, or both. © 2012 Paul White Twitter: @SQL_Kiwi email: [email protected]

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  • Fun with Aggregates

    - by Paul White
    There are interesting things to be learned from even the simplest queries.  For example, imagine you are given the task of writing a query to list AdventureWorks product names where the product has at least one entry in the transaction history table, but fewer than ten. One possible query to meet that specification is: SELECT p.Name FROM Production.Product AS p JOIN Production.TransactionHistory AS th ON p.ProductID = th.ProductID GROUP BY p.ProductID, p.Name HAVING COUNT_BIG(*) < 10; That query correctly returns 23 rows (execution plan and data sample shown below): The execution plan looks a bit different from the written form of the query: the base tables are accessed in reverse order, and the aggregation is performed before the join.  The general idea is to read all rows from the history table, compute the count of rows grouped by ProductID, merge join the results to the Product table on ProductID, and finally filter to only return rows where the count is less than ten. This ‘fully-optimized’ plan has an estimated cost of around 0.33 units.  The reason for the quote marks there is that this plan is not quite as optimal as it could be – surely it would make sense to push the Filter down past the join too?  To answer that, let’s look at some other ways to formulate this query.  This being SQL, there are any number of ways to write logically-equivalent query specifications, so we’ll just look at a couple of interesting ones.  The first query is an attempt to reverse-engineer T-SQL from the optimized query plan shown above.  It joins the result of pre-aggregating the history table to the Product table before filtering: SELECT p.Name FROM ( SELECT th.ProductID, cnt = COUNT_BIG(*) FROM Production.TransactionHistory AS th GROUP BY th.ProductID ) AS q1 JOIN Production.Product AS p ON p.ProductID = q1.ProductID WHERE q1.cnt < 10; Perhaps a little surprisingly, we get a slightly different execution plan: The results are the same (23 rows) but this time the Filter is pushed below the join!  The optimizer chooses nested loops for the join, because the cardinality estimate for rows passing the Filter is a bit low (estimate 1 versus 23 actual), though you can force a merge join with a hint and the Filter still appears below the join.  In yet another variation, the < 10 predicate can be ‘manually pushed’ by specifying it in a HAVING clause in the “q1” sub-query instead of in the WHERE clause as written above. The reason this predicate can be pushed past the join in this query form, but not in the original formulation is simply an optimizer limitation – it does make efforts (primarily during the simplification phase) to encourage logically-equivalent query specifications to produce the same execution plan, but the implementation is not completely comprehensive. Moving on to a second example, the following query specification results from phrasing the requirement as “list the products where there exists fewer than ten correlated rows in the history table”: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) < 10 ); Unfortunately, this query produces an incorrect result (86 rows): The problem is that it lists products with no history rows, though the reasons are interesting.  The COUNT_BIG(*) in the EXISTS clause is a scalar aggregate (meaning there is no GROUP BY clause) and scalar aggregates always produce a value, even when the input is an empty set.  In the case of the COUNT aggregate, the result of aggregating the empty set is zero (the other standard aggregates produce a NULL).  To make the point really clear, let’s look at product 709, which happens to be one for which no history rows exist: -- Scalar aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709;   -- Vector aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709 GROUP BY th.ProductID; The estimated execution plans for these two statements are almost identical: You might expect the Stream Aggregate to have a Group By for the second statement, but this is not the case.  The query includes an equality comparison to a constant value (709), so all qualified rows are guaranteed to have the same value for ProductID and the Group By is optimized away. In fact there are some minor differences between the two plans (the first is auto-parameterized and qualifies for trivial plan, whereas the second is not auto-parameterized and requires cost-based optimization), but there is nothing to indicate that one is a scalar aggregate and the other is a vector aggregate.  This is something I would like to see exposed in show plan so I suggested it on Connect.  Anyway, the results of running the two queries show the difference at runtime: The scalar aggregate (no GROUP BY) returns a result of zero, whereas the vector aggregate (with a GROUP BY clause) returns nothing at all.  Returning to our EXISTS query, we could ‘fix’ it by changing the HAVING clause to reject rows where the scalar aggregate returns zero: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) BETWEEN 1 AND 9 ); The query now returns the correct 23 rows: Unfortunately, the execution plan is less efficient now – it has an estimated cost of 0.78 compared to 0.33 for the earlier plans.  Let’s try adding a redundant GROUP BY instead of changing the HAVING clause: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY th.ProductID HAVING COUNT_BIG(*) < 10 ); Not only do we now get correct results (23 rows), this is the execution plan: I like to compare that plan to quantum physics: if you don’t find it shocking, you haven’t understood it properly :)  The simple addition of a redundant GROUP BY has resulted in the EXISTS form of the query being transformed into exactly the same optimal plan we found earlier.  What’s more, in SQL Server 2008 and later, we can replace the odd-looking GROUP BY with an explicit GROUP BY on the empty set: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ); I offer that as an alternative because some people find it more intuitive (and it perhaps has more geek value too).  Whichever way you prefer, it’s rather satisfying to note that the result of the sub-query does not exist for a particular correlated value where a vector aggregate is used (the scalar COUNT aggregate always returns a value, even if zero, so it always ‘EXISTS’ regardless which ProductID is logically being evaluated). The following query forms also produce the optimal plan and correct results, so long as a vector aggregate is used (you can probably find more equivalent query forms): WHERE Clause SELECT p.Name FROM Production.Product AS p WHERE ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) < 10; APPLY SELECT p.Name FROM Production.Product AS p CROSS APPLY ( SELECT NULL FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ) AS ca (dummy); FROM Clause SELECT q1.Name FROM ( SELECT p.Name, cnt = ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) FROM Production.Product AS p ) AS q1 WHERE q1.cnt < 10; This last example uses SUM(1) instead of COUNT and does not require a vector aggregate…you should be able to work out why :) SELECT q.Name FROM ( SELECT p.Name, cnt = ( SELECT SUM(1) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID ) FROM Production.Product AS p ) AS q WHERE q.cnt < 10; The semantics of SQL aggregates are rather odd in places.  It definitely pays to get to know the rules, and to be careful to check whether your queries are using scalar or vector aggregates.  As we have seen, query plans do not show in which ‘mode’ an aggregate is running and getting it wrong can cause poor performance, wrong results, or both. © 2012 Paul White Twitter: @SQL_Kiwi email: [email protected]

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  • Complex event system for DungeonKeeper like game

    - by paul424
    I am working on opensource GPL3 game. http://opendungeons.sourceforge.net/ , new coders would be welcome. Now there's design question regarding Event System: We want to improve the game logic, that is program a new event system. I will just repost what's settled up already on http://forum.freegamedev.net/viewtopic.php?f=45&t=3033. From the discussion came the idea of the Publisher / Subscriber pattern + "domains": My current idea is to use the subscirbers / publishers model. Its similar to Observable pattern, but instead one subscribes to Events types, not Object's Events. For each Event would like to have both static and dynamic type. Static that is its's type would be resolved by belonging to the proper inherited class from Event. That is from Event we would have EventTile, EventCreature, EvenMapLoader, EventGameMap etc. From that there are of course subtypes like EventCreature would be EventKobold, EventKnight, EventTentacle etc. The listeners would collect the event from publishers, and send them subcribers , each of them would be a global singleton. The Listeners type hierachy would exactly mirror the type hierarchy of Events. In each constructor of Event type, the created instance would notify the proper listeners. That is when calling EventKnight the proper ctor would notify the Listeners : EventListener, CreatureLisener and KnightListener. The default action for an listner would be to notify all subscribers, but there would be some exceptions , like EventAttack would notify AttackListener which would dispatch event by the dynamic part ( that is the Creature pointer or hash). Any comments ? #include <vector> class Subscriber; class SubscriberAttack; class Event{ private: int foo; int bar; protected: // static std::vector<Publisher*> publishersList; static std::vector<Subscriber*> subscribersList; static std::vector<Event*> eventQueue; public: Event(){ eventQueue.push_back(this); } static int subscribe(Subscriber* ss); static int unsubscribe(Subscriber* ss); //static int reg_publisher(Publisher* pp); //static int unreg_publisher(Publisher* pp); }; // class Publisher{ // }; class Subscriber{ public: int (*newEvent) (Event* ee); Subscriber( ){ Event::subscribe(this); } Subscriber( int (*fp) (Event* ee) ):newEvent(fp){ Subscriber(); } ~Subscriber(){ Event::unsubscribe(this); } }; class EventAttack: Event{ private: int foo; int bar; protected: // static std::vector<Publisher*> publishersList; static std::vector<SubscriberAttack*> subscribersList; static std::vector<EventAttack*> eventQueue; public: EventAttack(){ eventQueue.push_back(this); } static int subscribe(SubscriberAttack* ss); static int unsubscribe(SubscriberAttack* ss); //static int reg_publisher(Publisher* pp); //static int unreg_publisher(Publisher* pp); }; class AttackSubscriber :Subscriber{ public: int (*newEvent) (EventAttack* ee); AttackSubscriber( ){ EventAttack::subscribe(this); } AttackSubscriber( int (*fp) (EventAttack* ee) ):newEventAttack(fp){ AttackSubscriber(); } ~AttackSubscriber(){ EventAttack::unsubscribe(this); } }; From that point, others wanted the Subject-Observer pattern, that is one would subscribe to all event types produced by particular object. That way it came out to add the domain system : Huh, to meet the ability to listen to particular game's object events, I though of introducing entity domains . Domains are trees, which nodes are labeled by unique names for each level. ( like the www addresses ). Each Entity wanting to participate in our event system ( that is be able to publish / produce events ) should at least now its domain name. That would end up in Player1/Room/Treasury/#24 or Player1/Creature/Kobold/#3 producing events. The subscriber picks some part of a tree. For example by specifiing subtree with the root in one of the nodes like Player1/Room/* ,would subscribe us to all Players1's room's event, and Player1/Creature/Kobold/#3 would subscribe to Players' third kobold's event. Does such event system make sense to you ? I have many implementation details to ask as well, but first let's start some general discussion. Note1: Notice that in the case of a fight between two creatues fight , the creature being attacked would have to throw an event, becuase it is HE/SHE/IT who have its domain address. So that would be BeingAttackedEvent() etc. I will edit that post if some other reflections on this would come out. Note2: the existing class hierarchy might be used to get the domains addresses being build in constructor . In a ctor you would just add + ."className" to domain address. If you are in a class'es hierarchy leaf constructor one might use nextID , hash or any other charactteristic, just to make the addresses distinguishable . Note3:subscribing to all entity's Events would require knowledge of all possible events produced by this entity . This could be done in one function call, but information on E produced would have to be handled for every Entity. SmartNote4 : Finding proper subscribers in a tree would be easy. One would start in particular Leaf for example Player1/Creature/Kobold/#3 and go up one parent a time , notifiying each Subscriber in a Node ie. : Player1/Creature/Kobold/* , Player1/Creature/* , Player1/* etc, , up to a root that is /* .<<<< Note5: The Event system was needed to have some way of incorporating Angelscript code into application. So the Event dispatcher was to be a gate to A-script functions. But it came out to this one.

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  • Re: Help with Boost Grammar

    - by Decmac04
    I have redesigned and extended the grammar I asked about earlier as shown below: // BIFAnalyser.cpp : Defines the entry point for the console application. // // /*============================================================================= Copyright (c) Temitope Jos Onunkun 2010 http://www.dcs.kcl.ac.uk/pg/onun/ Use, modification and distribution is subject to the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) =============================================================================*/ //////////////////////////////////////////////////////////////////////////// // // // B Machine parser using the Boost "Grammar" and "Semantic Actions". // // // //////////////////////////////////////////////////////////////////////////// include include include include include include //////////////////////////////////////////////////////////////////////////// using namespace std; using namespace boost::spirit; //////////////////////////////////////////////////////////////////////////// // // Semantic Actions // //////////////////////////////////////////////////////////////////////////// // // namespace { //semantic action function on individual lexeme void do_noint(char const* start, char const* end) { string str(start, end); if (str != "NAT1") cout << "PUSH(" << str << ')' << endl; } //semantic action function on addition of lexemes void do_add(char const*, char const*) { cout << "ADD" << endl; // for(vector::iterator vi = strVect.begin(); vi < strVect.end(); ++vi) // cout << *vi << " "; } //semantic action function on subtraction of lexemes void do_subt(char const*, char const*) { cout << "SUBTRACT" << endl; } //semantic action function on multiplication of lexemes void do_mult(char const*, char const*) { cout << "\nMULTIPLY" << endl; } //semantic action function on division of lexemes void do_div(char const*, char const*) { cout << "\nDIVIDE" << endl; } // // vector flowTable; //semantic action function on simple substitution void do_sSubst(char const* start, char const* end) { string str(start, end); //use boost tokenizer to break down tokens typedef boost::tokenizer Tokenizer; boost::char_separator sep(" -+/*:=()",0,boost::drop_empty_tokens); // char separator definition Tokenizer tok(str, sep); Tokenizer::iterator tok_iter = tok.begin(); pair dependency; //create a pair object for dependencies //create a vector object to store all tokens vector dx; // int counter = 0; // tracks token position for(tok.begin(); tok_iter != tok.end(); ++tok_iter) //save all tokens in vector { dx.push_back(*tok_iter ); } counter = dx.size(); // vector d_hat; //stores set of dependency pairs string dep; //pairs variables as string object // dependency.first = *tok.begin(); vector FV; for(int unsigned i=1; i < dx.size(); i++) { // if(!atoi(dx.at(i).c_str()) && (dx.at(i) !=" ")) { dependency.second = dx.at(i); dep = dependency.first + "|-" + dependency.second + " "; d_hat.push_back(dep); vector<string> row; row.push_back(dependency.first); //push x_hat into first column of each row for(unsigned int j=0; j<2; j++) { row.push_back(dependency.second);//push an element (column) into the row } flowTable.push_back(row); //Add the row to the main vector } } //displays internal representation of information flow table cout << "\n****************\nDependency Table\n****************\n"; cout << "X_Hat\tDx\tG_Hat\n"; cout << "-----------------------------\n"; for(unsigned int i=0; i < flowTable.size(); i++) { for(unsigned int j=0; j<2; j++) { cout << flowTable[i][j] << "\t "; } if (*tok.begin() != "WHILE" ) //if there are no global flows, cout << "\t{}"; //display empty set cout << "\n"; } cout << "***************\n\n"; for(int unsigned j=0; j < FV.size(); j++) { if(FV.at(j) != dependency.second) dep = dependency.first + "|-" + dependency.second + " "; d_hat.push_back(dep); } cout << "PUSH(" << str << ')' << endl; cout << "\n*******\nDependency pairs\n*******\n"; for(int unsigned i=0; i < d_hat.size(); i++) cout << d_hat.at(i) << "\n...\n"; cout << "\nSIMPLE SUBSTITUTION\n\n"; } //semantic action function on multiple substitution void do_mSubst(char const* start, char const* end) { string str(start, end); cout << "PUSH(" << str << ')' << endl; //cout << "\nMULTIPLE SUBSTITUTION\n\n"; } //semantic action function on unbounded choice substitution void do_mChoice(char const* start, char const* end) { string str(start, end); cout << "PUSH(" << str << ')' << endl; cout << "\nUNBOUNDED CHOICE SUBSTITUTION\n\n"; } void do_logicExpr(char const* start, char const* end) { string str(start, end); //use boost tokenizer to break down tokens typedef boost::tokenizer Tokenizer; boost::char_separator sep(" -+/*=:()<",0,boost::drop_empty_tokens); // char separator definition Tokenizer tok(str, sep); Tokenizer::iterator tok_iter = tok.begin(); //pair dependency; //create a pair object for dependencies //create a vector object to store all tokens vector dx; for(tok.begin(); tok_iter != tok.end(); ++tok_iter) //save all tokens in vector { dx.push_back(*tok_iter ); } for(unsigned int i=0; i cout << "PUSH(" << str << ')' << endl; cout << "\nPREDICATE\n\n"; } void do_predicate(char const* start, char const* end) { string str(start, end); cout << "PUSH(" << str << ')' << endl; cout << "\nMULTIPLE PREDICATE\n\n"; } void do_ifSelectPre(char const* start, char const* end) { string str(start, end); //if cout << "PUSH(" << str << ')' << endl; cout << "\nPROTECTED SUBSTITUTION\n\n"; } //semantic action function on machine substitution void do_machSubst(char const* start, char const* end) { string str(start, end); cout << "PUSH(" << str << ')' << endl; cout << "\nMACHINE SUBSTITUTION\n\n"; } } //////////////////////////////////////////////////////////////////////////// // // Machine Substitution Grammar // //////////////////////////////////////////////////////////////////////////// // Simple substitution grammar parser with integer values removed struct Substitution : public grammar { template struct definition { definition(Substitution const& ) { machine_subst = ( (simple_subst) | (multi_subst) | (if_select_pre_subst) | (unbounded_choice) )[&do_machSubst] ; unbounded_choice = str_p("ANY") ide_list str_p("WHERE") predicate str_p("THEN") machine_subst str_p("END") ; if_select_pre_subst = ( ( str_p("IF") predicate str_p("THEN") machine_subst *( str_p("ELSIF") predicate machine_subst ) !( str_p("ELSE") machine_subst) str_p("END") ) | ( str_p("SELECT") predicate str_p("THEN") machine_subst *( str_p("WHEN") predicate machine_subst ) !( str_p("ELSE") machine_subst) str_p("END")) | ( str_p("PRE") predicate str_p("THEN") machine_subst str_p("END") ) )[&do_ifSelectPre] ; multi_subst = ( (machine_subst) *( ( str_p("||") (machine_subst) ) | ( str_p("[]") (machine_subst) ) ) ) [&do_mSubst] ; simple_subst = (identifier str_p(":=") arith_expr) [&do_sSubst] ; expression = predicate | arith_expr ; predicate = ( (logic_expr) *( ( ch_p('&') (logic_expr) ) | ( str_p("OR") (logic_expr) ) ) )[&do_predicate] ; logic_expr = ( identifier (str_p("<") arith_expr) | (str_p("<") arith_expr) | (str_p("/:") arith_expr) | (str_p("<:") arith_expr) | (str_p("/<:") arith_expr) | (str_p("<<:") arith_expr) | (str_p("/<<:") arith_expr) | (str_p("<=") arith_expr) | (str_p("=") arith_expr) | (str_p("=") arith_expr) | (str_p("=") arith_expr) ) [&do_logicExpr] ; arith_expr = term *( ('+' term)[&do_add] | ('-' term)[&do_subt] ) ; term = factor ( ('' factor)[&do_mult] | ('/' factor)[&do_div] ) ; factor = lexeme_d[( identifier | +digit_p)[&do_noint]] | '(' expression ')' | ('+' factor) ; ide_list = identifier *( ch_p(',') identifier ) ; identifier = alpha_p +( alnum_p | ch_p('_') ) ; } rule machine_subst, unbounded_choice, if_select_pre_subst, multi_subst, simple_subst, expression, predicate, logic_expr, arith_expr, term, factor, ide_list, identifier; rule<ScannerT> const& start() const { return predicate; //return multi_subst; //return machine_subst; } }; }; //////////////////////////////////////////////////////////////////////////// // // Main program // //////////////////////////////////////////////////////////////////////////// int main() { cout << "*********************************\n\n"; cout << "\t\t...Machine Parser...\n\n"; cout << "*********************************\n\n"; // cout << "Type an expression...or [q or Q] to quit\n\n"; string str; int machineCount = 0; char strFilename[256]; //file name store as a string object do { cout << "Please enter a filename...or [q or Q] to quit:\n\n "; //prompt for file name to be input //char strFilename[256]; //file name store as a string object cin strFilename; if(*strFilename == 'q' || *strFilename == 'Q') //termination condition return 0; ifstream inFile(strFilename); // opens file object for reading //output file for truncated machine (operations only) if (inFile.fail()) cerr << "\nUnable to open file for reading.\n" << endl; inFile.unsetf(std::ios::skipws); Substitution elementary_subst; // Simple substitution parser object string next; while (inFile str) { getline(inFile, next); str += next; if (str.empty() || str[0] == 'q' || str[0] == 'Q') break; parse_info< info = parse(str.c_str(), elementary_subst !end_p, space_p); if (info.full) { cout << "\n-------------------------\n"; cout << "Parsing succeeded\n"; cout << "\n-------------------------\n"; } else { cout << "\n-------------------------\n"; cout << "Parsing failed\n"; cout << "stopped at: " << info.stop << "\"\n"; cout << "\n-------------------------\n"; } } } while ( (*strFilename != 'q' || *strFilename !='Q')); return 0; } However, I am experiencing the following unexpected behaviours on testing: The text files I used are: f1.txt, ... containing ...: debt:=(LoanRequest+outstandingLoan1)*20 . f2.txt, ... containing ...: debt:=(LoanRequest+outstandingLoan1)*20 || newDebt := loanammount-paidammount || price := purchasePrice + overhead + bb . f3.txt, ... containing ...: yy < (xx+7+ww) . f4.txt, ... containing ...: yy < (xx+7+ww) & yy : NAT . When I use multi_subst as start rule both files (f1 and f2) are parsed correctly; When I use machine_subst as start rule file f1 parse correctly, while file f2 fails, producing the error: “Parsing failed stopped at: || newDebt := loanammount-paidammount || price := purchasePrice + overhead + bb” When I use predicate as start symbol, file f3 parse correctly, but file f4 yields the error: “ “Parsing failed stopped at: & yy : NAT” Can anyone help with the grammar, please? It appears there are problems with the grammar that I have so far been unable to spot.

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  • Help with Boost Grammar

    - by Decmanc04
    I have been using the following win32 console code to try to parse a B Machine Grammar embedded within C++ using Boost Spirit grammar template. I am a relatively new Boost user. The code compiles, but when I run the .exe file produced by VC++2008, the program partially parses the input file. I believe the problem is with my grammar definition or the functions attached as semantic atctions. The code is given below: // BIFAnalyser.cpp : Defines the entry point for the console application. // // /*============================================================================= Copyright (c) Temitope Jos Onunkun 2010 http://www.dcs.kcl.ac.uk/pg/onun/ Use, modification and distribution is subject to the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) =============================================================================*/ //////////////////////////////////////////////////////////////////////////// // // // B Machine parser using the Boost "Grammar" and "Semantic Actions". // // // //////////////////////////////////////////////////////////////////////////// #include <boost/spirit/core.hpp> #include <boost/tokenizer.hpp> #include <iostream> #include <string> #include <fstream> #include <vector> #include <utility> /////////////////////////////////////////////////////////////////////////////////////////// using namespace std; using namespace boost::spirit; /////////////////////////////////////////////////////////////////////////////////////////// // // Semantic actions // //////////////////////////////////////////////////////////////////////////// vector<string> strVect; namespace { //semantic action function on individual lexeme void do_noint(char const* str, char const* end) { string s(str, end); if(atoi(str)) { ; } else { strVect.push_back(s); cout << "PUSH(" << s << ')' << endl; } } //semantic action function on addition of lexemes void do_add(char const*, char const*) { cout << "ADD" << endl; for(vector<string>::iterator vi = strVect.begin(); vi < strVect.end(); ++vi) cout << *vi << " "; } //semantic action function on subtraction of lexemes void do_subt(char const*, char const*) { cout << "SUBTRACT" << endl; for(vector<string>::iterator vi = strVect.begin(); vi < strVect.end(); ++vi) cout << *vi << " "; } //semantic action function on multiplication of lexemes void do_mult(char const*, char const*) { cout << "\nMULTIPLY" << endl; for(vector<string>::iterator vi = strVect.begin(); vi < strVect.end(); ++vi) cout << *vi << " "; cout << "\n"; } //semantic action function on division of lexemes void do_div(char const*, char const*) { cout << "\nDIVIDE" << endl; for(vector<string>::iterator vi = strVect.begin(); vi < strVect.end(); ++vi) cout << *vi << " "; } //semantic action function on simple substitution void do_sSubst(char const* str, char const* end) { string s(str, end); //use boost tokenizer to break down tokens typedef boost::tokenizer<boost::char_separator<char> > Tokenizer; boost::char_separator<char> sep("-+/*:=()"); // default char separator Tokenizer tok(s, sep); Tokenizer::iterator tok_iter = tok.begin(); pair<string, string > dependency; //create a pair object for dependencies //save first variable token in simple substitution dependency.first = *tok.begin(); //create a vector object to store all tokens vector<string> dx; // for( ; tok_iter != tok.end(); ++tok_iter) //save all tokens in vector { dx.push_back(*tok_iter ); } vector<string> d_hat; //stores set of dependency pairs string dep; //pairs variables as string object for(int unsigned i=1; i < dx.size()-1; i++) { dependency.second = dx.at(i); dep = dependency.first + "|->" + dependency.second + " "; d_hat.push_back(dep); } cout << "PUSH(" << s << ')' << endl; for(int unsigned i=0; i < d_hat.size(); i++) cout <<"\n...\n" << d_hat.at(i) << " "; cout << "\nSIMPLE SUBSTITUTION\n"; } //semantic action function on multiple substitution void do_mSubst(char const* str, char const* end) { string s(str, end); //use boost tokenizer to break down tokens typedef boost::tokenizer<boost::char_separator<char> > Tok; boost::char_separator<char> sep("-+/*:=()"); // default char separator Tok tok(s, sep); Tok::iterator tok_iter = tok.begin(); // string start = *tok.begin(); vector<string> mx; for( ; tok_iter != tok.end(); ++tok_iter) //save all tokens in vector { mx.push_back(*tok_iter ); } mx.push_back("END\n"); //add a marker "end" for(unsigned int i=0; i<mx.size(); i++) { // if(mx.at(i) == "END" || mx.at(i) == "||" ) // break; // else if( mx.at(i) == "||") // do_sSubst(str, end); // else // { // do_sSubst(str, end); // } cout << "\nTokens ... " << mx.at(i) << " "; } cout << "PUSH(" << s << ')' << endl; cout << "MULTIPLE SUBSTITUTION\n"; } } //////////////////////////////////////////////////////////////////////////// // // Simple Substitution Grammar // //////////////////////////////////////////////////////////////////////////// // Simple substitution grammar parser with integer values removed struct Substitution : public grammar<Substitution> { template <typename ScannerT> struct definition { definition(Substitution const& ) { multi_subst = (simple_subst [&do_mSubst] >> +( str_p("||") >> simple_subst [&do_mSubst]) ) ; simple_subst = (Identifier >> str_p(":=") >> expression)[&do_sSubst] ; Identifier = alpha_p >> +alnum_p//[do_noint] ; expression = term >> *( ('+' >> term)[&do_add] | ('-' >> term)[&do_subt] ) ; term = factor >> *( ('*' >> factor)[&do_mult] | ('/' >> factor)[&do_div] ) ; factor = lexeme_d[( (alpha_p >> +alnum_p) | +digit_p)[&do_noint]] | '(' >> expression >> ')' | ('+' >> factor) ; } rule<ScannerT> expression, term, factor, Identifier, simple_subst, multi_subst ; rule<ScannerT> const& start() const { return multi_subst; } }; }; //////////////////////////////////////////////////////////////////////////// // // Main program // //////////////////////////////////////////////////////////////////////////// int main() { cout << "************************************************************\n\n"; cout << "\t\t...Machine Parser...\n\n"; cout << "************************************************************\n\n"; // cout << "Type an expression...or [q or Q] to quit\n\n"; //prompt for file name to be input cout << "Please enter a filename...or [q or Q] to quit:\n\n "; char strFilename[256]; //file name store as a string object cin >> strFilename; ifstream inFile(strFilename); // opens file object for reading //output file for truncated machine (operations only) Substitution elementary_subst; // Simple substitution parser object string str, next; // inFile.open(strFilename); while (inFile >> str) { getline(cin, next); str += next; if (str.empty() || str[0] == 'q' || str[0] == 'Q') break; parse_info<> info = parse(str.c_str(), elementary_subst, space_p); if (info.full) { cout << "\n-------------------------\n"; cout << "Parsing succeeded\n"; cout << "\n-------------------------\n"; } else { cout << "\n-------------------------\n"; cout << "Parsing failed\n"; cout << "stopped at: \": " << info.stop << "\"\n"; cout << "\n-------------------------\n"; } } cout << "Please enter a filename...or [q or Q] to quit\n"; cin >> strFilename; return 0; } The contents of the file I tried to parse, which I named "mf7.txt" is given below: debt:=(LoanRequest+outstandingLoan1)*20 || newDebt := loanammount-paidammount The output when I execute the program is: ************************************************************ ...Machine Parser... ************************************************************ Please enter a filename...or [q or Q] to quit: c:\tplat\mf7.txt PUSH(LoanRequest) PUSH(outstandingLoan1) ADD LoanRequest outstandingLoan1 MULTIPLY LoanRequest outstandingLoan1 PUSH(debt:=(LoanRequest+outstandingLoan1)*20) ... debt|->LoanRequest ... debt|->outstandingLoan1 SIMPLE SUBSTITUTION Tokens ... debt Tokens ... LoanRequest Tokens ... outstandingLoan1 Tokens ... 20 Tokens ... END PUSH(debt:=(LoanRequest+outstandingLoan1)*20) MULTIPLE SUBSTITUTION ------------------------- Parsing failedstopped at: ": " ------------------------- My intention is to capture only the variables in the file, which I managed to do up to the "||" string. Clearly, the program is not parsing beyond the "||" string in the input file. I will appreciate assistance to fix the grammar. SOS, please.

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  • How to compile a C++ source code written for Linux/Unix on Windows Vista (code given)

    - by HTMZ
    I have a c++ source code that was written in linux/unix environment by some other author. It gives me errors when i compile it in windows vista environment. I am using Bloodshed Dev C++ v 4.9. please help. #include <iostream.h> #include <map> #include <vector> #include <string> #include <string.h> #include <strstream> #include <unistd.h> #include <stdlib.h> using namespace std; template <class T> class PrefixSpan { private: vector < vector <T> > transaction; vector < pair <T, unsigned int> > pattern; unsigned int minsup; unsigned int minpat; unsigned int maxpat; bool all; bool where; string delimiter; bool verbose; ostream *os; void report (vector <pair <unsigned int, int> > &projected) { if (minpat > pattern.size()) return; // print where & pattern if (where) { *os << "<pattern>" << endl; // what: if (all) { *os << "<freq>" << pattern[pattern.size()-1].second << "</freq>" << endl; *os << "<what>"; for (unsigned int i = 0; i < pattern.size(); i++) *os << (i ? " " : "") << pattern[i].first; } else { *os << "<what>"; for (unsigned int i = 0; i < pattern.size(); i++) *os << (i ? " " : "") << pattern[i].first << delimiter << pattern[i].second; } *os << "</what>" << endl; // where *os << "<where>"; for (unsigned int i = 0; i < projected.size(); i++) *os << (i ? " " : "") << projected[i].first; *os << "</where>" << endl; *os << "</pattern>" << endl; } else { // print found pattern only if (all) { *os << pattern[pattern.size()-1].second; for (unsigned int i = 0; i < pattern.size(); i++) *os << " " << pattern[i].first; } else { for (unsigned int i = 0; i < pattern.size(); i++) *os << (i ? " " : "") << pattern[i].first << delimiter << pattern[i].second; } *os << endl; } } void project (vector <pair <unsigned int, int> > &projected) { if (all) report(projected); map <T, vector <pair <unsigned int, int> > > counter; for (unsigned int i = 0; i < projected.size(); i++) { int pos = projected[i].second; unsigned int id = projected[i].first; unsigned int size = transaction[id].size(); map <T, int> tmp; for (unsigned int j = pos + 1; j < size; j++) { T item = transaction[id][j]; if (tmp.find (item) == tmp.end()) tmp[item] = j ; } for (map <T, int>::iterator k = tmp.begin(); k != tmp.end(); ++k) counter[k->first].push_back (make_pair <unsigned int, int> (id, k->second)); } for (map <T, vector <pair <unsigned int, int> > >::iterator l = counter.begin (); l != counter.end (); ) { if (l->second.size() < minsup) { map <T, vector <pair <unsigned int, int> > >::iterator tmp = l; tmp = l; ++tmp; counter.erase (l); l = tmp; } else { ++l; } } if (! all && counter.size () == 0) { report (projected); return; } for (map <T, vector <pair <unsigned int, int> > >::iterator l = counter.begin (); l != counter.end(); ++l) { if (pattern.size () < maxpat) { pattern.push_back (make_pair <T, unsigned int> (l->first, l->second.size())); project (l->second); pattern.erase (pattern.end()); } } } public: PrefixSpan (unsigned int _minsup = 1, unsigned int _minpat = 1, unsigned int _maxpat = 0xffffffff, bool _all = false, bool _where = false, string _delimiter = "/", bool _verbose = false): minsup(_minsup), minpat (_minpat), maxpat (_maxpat), all(_all), where(_where), delimiter (_delimiter), verbose (_verbose) {}; ~PrefixSpan () {}; istream& read (istream &is) { string line; vector <T> tmp; T item; while (getline (is, line)) { tmp.clear (); istrstream istrs ((char *)line.c_str()); while (istrs >> item) tmp.push_back (item); transaction.push_back (tmp); } return is; } ostream& run (ostream &_os) { os = &_os; if (verbose) *os << transaction.size() << endl; vector <pair <unsigned int, int> > root; for (unsigned int i = 0; i < transaction.size(); i++) root.push_back (make_pair (i, -1)); project (root); return *os; } void clear () { transaction.clear (); pattern.clear (); } }; int main (int argc, char **argv) { extern char *optarg; unsigned int minsup = 1; unsigned int minpat = 1; unsigned int maxpat = 0xffffffff; bool all = false; bool where = false; string delimiter = "/"; bool verbose = false; string type = "string"; int opt; while ((opt = getopt(argc, argv, "awvt:M:m:L:d:")) != -1) { switch(opt) { case 'a': all = true; break; case 'w': where = true; break; case 'v': verbose = true; break; case 'm': minsup = atoi (optarg); break; case 'M': minpat = atoi (optarg); break; case 'L': maxpat = atoi (optarg); break; case 't': type = string (optarg); break; case 'd': delimiter = string (optarg); break; default: cout << "Usage: " << argv[0] << " [-m minsup] [-M minpat] [-L maxpat] [-a] [-w] [-v] [-t type] [-d delimiter] < data .." << endl; return -1; } } if (type == "int") { PrefixSpan<unsigned int> prefixspan (minsup, minpat, maxpat, all, where, delimiter, verbose); prefixspan.read (cin); prefixspan.run (cout); }else if (type == "short") { PrefixSpan<unsigned short> prefixspan (minsup, minpat, maxpat, all, where, delimiter, verbose); prefixspan.read (cin); prefixspan.run (cout); } else if (type == "char") { PrefixSpan<unsigned char> prefixspan (minsup, minpat, maxpat, all, where, delimiter, verbose); prefixspan.read (cin); prefixspan.run (cout); } else if (type == "string") { PrefixSpan<string> prefixspan (minsup, minpat, maxpat, all, where, delimiter, verbose); prefixspan.read (cin); prefixspan.run (cout); } else { cerr << "Unknown Item Type: " << type << " : choose from [string|int|short|char]" << endl; return -1; } return 0; }

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  • How to disable SSLCompression on Apache httpd 2.2.15?

    - by Stefan Lasiewski
    I read about the CRIME attack against TLS Compression (CRIME is a successor to the BEAST attack against ssl & tls), and I want to protect my webservers against this attack by disabling SSL Compression, which was added to Apache 2.2.22 (See Bug 53219). I am running Scientific Linux 6.1, which ships with httpd-2.2.15. Security fixes for upstream versions of httpd 2.2 should be backported to this version. # rpm -q httpd httpd-2.2.15-15.sl6.1.x86_64 # httpd -V Server version: Apache/2.2.15 (Unix) Server built: Feb 14 2012 09:47:14 Server's Module Magic Number: 20051115:24 Server loaded: APR 1.3.9, APR-Util 1.3.9 Compiled using: APR 1.3.9, APR-Util 1.3.9 I tried SSLCompression off in my configuration, but that results in the following error message: # /etc/init.d/httpd restart Stopping httpd: [ OK ] Starting httpd: Syntax error on line 147 of /etc/httpd/httpd.conf: Invalid command 'SSLCompression', perhaps misspelled or defined by a module not included in the server configuration [FAILED] Is it possible to disable SSLCompression with this version of Apache Webserver?

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  • How to explain pointers to a Java/VB programmer

    - by Skeith
    I am writing a game and my friend has offered to help me as it is a RPG and will take a long time to do the "scripting" bit of the game. The problem is IMO he's not that good a programmer :( (add flame war here). He has only programmed in Java and VB and keeps saying really stupid things to me like "Why don't you drag and drop an onClick event" to design my UI when I'm using DirectX. I tried explaining pointers to him but his response was, if it's just a variable that holds a memory address, why don't you just use an int? I create an instance of an attack class and give the creature a pointer to it so if several creatures use the same attack there is only one instance of it. He keeps saying why not put if statements in the creature class for every attack class and set true for the ones that are there. He has programmed mainly in VB and a little in Java just to learn OOP. How can I explain advanced C++ concepts like pointers and memory management to him? He just doesn't understand there are no super functions like form.show in C++.

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  • Today in the OTN Lounge (Tuesday October 2, 2012)

    - by Bob Rhubart
    Here's a quick rundown of today's activities in the OTN Lounge:   (OTN Lounge hours today: 8:00 am - 7:00 pm) 9:00 am - 1:00 pm RAC Attack Learn about Oracle Real Application Clustering (RAC) in this collaborative event. You'll work with experts from the IOUG RAC SIG to get an Oracle Database 11gR2 RAC cluster running inside a virtual machine. For more information: RAC attack at Oracle Open World (Pythian Blog) RAC Attack - Oracle Cluster Database at Home/Events (WikiBooks) 4:30 pm - 8:00 pm Oracle Social Network Developer Challenge Office Hours Find information, expertise, and a collaborative work environment for those participating in the OSN Developer Challenge. Click here for more information. 4:30 pm - 6:00 pm Oracle Database / Oracle Fusion Middleware Tweet Meet Free as in beer! Oracle Database and Oracle Fusion Middleware tweeters, gather in the OTN Lounge for refreshments and conversation with fellow tweeters and Oracle Database and Middleware experts. The OTN Lounge is located in the Howard St. Tent, between 3rd and 4th, directly between Moscone North and Moscone South. Access to the OTN Lounge requires an Oracle OpenWorld or JavaOne conference badge.

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  • Find vertices of a convex hull

    - by Jeff Bullard
    I am attempting to do this within CGAL. From a 3D point cloud, find the convex hull, then loop over the finite facets of the convex hull and print each facet's vertices. It seems like there should be a straightforward way to do this; I would have expected that 3D polyhedra would own a vector of facet objects, each of which in turn would own a vector of its edges, each of which in turn would own a vector of its vertices, and that their would be some access through this hierarchy using iterators. But so far I have been unable to find a simple way to navigate through this hierarchy (if it exists).

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  • What's the most efficient way to find barycentric coordinates?

    - by bobobobo
    In my profiler, finding barycentric coordinates is apparently somewhat of a bottleneck. I am looking to make it more efficient. It follows the method in shirley, where you compute the area of the triangles formed by embedding the point P inside the triangle. Code: Vector Triangle::getBarycentricCoordinatesAt( const Vector & P ) const { Vector bary ; // The area of a triangle is real areaABC = DOT( normal, CROSS( (b - a), (c - a) ) ) ; real areaPBC = DOT( normal, CROSS( (b - P), (c - P) ) ) ; real areaPCA = DOT( normal, CROSS( (c - P), (a - P) ) ) ; bary.x = areaPBC / areaABC ; // alpha bary.y = areaPCA / areaABC ; // beta bary.z = 1.0f - bary.x - bary.y ; // gamma return bary ; } This method works, but I'm looking for a more efficient one!

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  • How do i mitigate DDOS attacks on static servers?

    - by acidzombie24
    Here is a slightly different take on DDOS attacks. Rather than a server with dynamic content being attack i was curious how to deal with attacks on servers with STATIC CONTENT. This means cpu tends to not be an issue. Its either bandwidth or connection problems. How would i mitigate a DDOS attack knowing nothing about the attacker (for example country, ip address or anything else). I was wondering is shorting the timeout and increasing amount of connections is an acceptable solution? Or maybe that is completely useless? Also i would limit the amount of connections per IP address. Would the above help or be pointless? Keeping in mind everything is static checking for multiple request of the same page (html, css, js, etc) could be a sign of a attack. What are some measures i can take on a static content server?

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