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  • Is C# development effectively inseparable from the IDE you use?

    - by Ghopper21
    I'm a Python programmer learning C# who is trying to stop worrying and just love C# for what it is, rather than constantly comparing it back to Python. I'm really get caught up on one point: the lack of explicitness about where things are defined, as detailed in this Stack Overflow question. In short: in C#, using foo doesn't tell you what names from foo are being made available, which is analogous to from foo import * in Python -- a form that is discouraged within Python coding culture for being implicit rather than the more explicit approach of from foo import bar. I was rather struck by the Stack Overflow answers to this point from C# programmers, which was that in practice this lack of explicitness doesn't really matter because in your IDE (presumably Visual Studio) you can just hover over a name and be told by the system where the name is coming from. E.g.: Now, in theory I realise this means when you're looking with a text editor, you can't tell where the types come from in C#... but in practice, I don't find that to be a problem. How often are you actually looking at code and can't use Visual Studio? This is revelatory to me. Many Python programmers prefer a text editor approach to coding, using something like Sublime Text 2 or vim, where it's all about the code, plus command line tools and direct access and manipulation of folders and files. The idea of being dependent on an IDE to understand code at such a basic level seems anathema. It seems C# culture is radically different on this point. And I wonder if I just need to accept and embrace that as part of my learning of C#. Which leads me to my question here: is C# development effectively inseparable from the IDE you use?

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  • Amazon EC2 vs Dedicated server at Hetzner, what's the use for EC2?

    - by C-Blu
    After searching the web I still can't find the reason to use EC2. What's the point to scale EC2? If you expect a huge burst in traffic, they say. OK, but what if you already have a couple of sites with good traffic, and for example medium reserved EC2 instance is not enough. You are paying $36.60(medium reserved for 1year) in EU(Ireland) + traffic + optional expenses for databases and S3 if you use them. Of course as some point when you are under $56.6-$66.1 you can optimize your hosting costs with Amazon EC2. But when you get at some point if purchase EX4 server from Hetzner, it will surpass your perfomance needs for a long time, before you get a massive traffic. (I am wrong?) CPU: i7-2600 Quadcore (3.4-3.8 Ghz) RAM: 16 GB HDD: 2x3 TB SATA (6 Gbit/s) - I think that disc performance of a dedicated is better then of Amazon EBS Traffic: 10 TiB in month included. This is what you get from Hetzner for $56(- 19% VAT) or $66 for EU residents. Please, tell me what's the reason to use Amazon? Which load won't a server from Hetzner take, but Amazon Auto Scaling will? The maintenance of dedicated vs EC2 is still the same? Or hardware failure at Amazon, won't ruin your EBS storage? I'm still not at the level when I need expensive hosting, but want to know beforehand, just to be sure if Amazon infrastructure is better then pure performance of Hetzner's hardware.

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  • QuickTimeInstaller causing me buckets of issues

    - by Chadworthington
    Today I saw this message: After it installed and I rebooted, I was getting the Blue Screen of Death every few clicks. So...to resolve, I restored to a Restore Point when all was working, 2 days ago. Then, QuickTime reappeared and tried to reinstall itself. Is this iTunes related? or might it be related to Windows Live Messenger? Any suggestions on how to stop this auto installation? Update: Rolling back to a previous Restore Point temporarily fixed the issue but the patch was automatically applied a second time. Then, I made the horrible mistake of uninstalling iTunes and this caused my previous old restore point to be wiped away because of a limited amount of space that I alloted to the Windows Restore functionality. I fear that I will be faced with many issues ahead... Please help

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  • Restrict movement within a radius

    - by Phil
    I asked a similar question recently but now I think I know more about what I really want to know. I can answer my own question if I get to understand this bit. I have a situation where a sprite's center point needs to be constrained within a certain boundary in 2d space. The boundary is circular so the sprite is constrained within a radius. This radius is defined as a distance from the center of a certain point. I know the position of the center point and I can track the center position of the sprite. This is the code to detect the distance: float distance = Vector2.Distance(centerPosition, spritePosition)); if (distance > allowedDistance) { } The positions can be wherever on the grid, they are not described as in between -1 or 1. So basically the detecting code works, it only prints when the sprite is outside of it's boundary I just don't know what to do when it oversteps. Please explain any math used as I really want to understand what you're thinking to be able to elaborate on it myself.

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  • 2d game view camera zoom, rotation & offset using 'Filter' / 'Shader' processing?

    - by Arthur Wulf White
    I wish to add the ability to zoom-in, zoom-out, rotate and move the view in a top-down view over a collection of points and lines in a large 2d map. I split the map into a grid so I only need to render the points that are 'near' the camera. My question is, how do I render a point A(Xp,Yp) assuming the following details: Offset of the camera pov from the origin of the map is: Xc, Yc Meaning the camera center is positioned on top of that point. If there's a point in Xc, Yc it is positioned in the center of the screen. The rotation angle is: alpha The scale is: S Read my answer first. I am thinking there is more optimized solution, thanks. My question is how to include the following improvement: I read in the AS3 Bible book that: In regards to ShaderInput, You can use these methods to coerce Pixel Bender to crunch huge sets of data masquerading as images, without doing too much work on the ActionScript side to make them look like images. Meaning if I am performing the same linear function on a lot of items, I can do it all at once if I use Shaders correctly and save processing time. Does anyone know how that is accomplished? Here is a sample of what I mean: http://wonderfl.net/c/eFp0/

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  • How do you plan your asynchronous code?

    - by NullOrEmpty
    I created a library that is a invoker for a web service somewhere else. The library exposes asynchronous methods, since web service calls are a good candidate for that matter. At the beginning everything was just fine, I had methods with easy to understand operations in a CRUD fashion, since the library is a kind of repository. But then business logic started to become complex, and some of the procedures involves the chaining of many of these asynchronous operations, sometimes with different paths depending on the result value, etc.. etc.. Suddenly, everything is very messy, to stop the execution in a break point it is not very helpful, to find out what is going on or where in the process timeline have you stopped become a pain... Development becomes less quick, less agile, and to catch those bugs that happens once in a 1000 times becomes a hell. From the technical point, a repository that exposes asynchronous methods looked like a good idea, because some persistence layers could have delays, and you can use the async approach to do the most of your hardware. But from the functional point of view, things became very complex, and considering those procedures where a dozen of different calls were needed... I don't know the real value of the improvement. After read about TPL for a while, it looked like a good idea for managing tasks, but in the moment you have to combine them and start to reuse existing functionality, things become very messy. I have had a good experience using it for very concrete scenarios, but bad experience using them broadly. How do you work asynchronously? Do you use it always? Or just for long running processes? Thanks.

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  • Is there supposed to be a Windows Network folder in the file manager?

    - by Cindy
    I pulled my hard drive out of my computer and started with a bootable usb version of Ubuntu, which I am using that at this point. At first boot, I see that there is a Windows folder when browsing network. Since there is no operating system present, besides the usb that I boot from, should there be a Windows network folder? Original question First of all I just want to say, I wish I had tried Ubuntu a couple years ago when I first heard about it, but I was like a lot of the population and went with the "easy way" and stuck with Windows because I didn't want to take the time to learn something new. Well, about 3 months ago I realized someone had hacked into my computer, and then found they had hacked my facebook account so I decided I had better do a complete credit check. I found student loans (totalling about 30,000 so far) had recently showed up on my credit report. I think it's going to be a long, long road to recovery now but I'm hoping Ubuntu will be a start and definitely an eye opener. My relationship with Windows is over. I had 3 antivirus programs running, none were protecting me like I thought they were. Turned out a free program that I downloaded was the only one that could detect and clean the virus, but by then it was too late. Anyhow, my question is, I pulled my hard drive out of my computer and started with a bootable usb version of Ubuntu, which I am using that at this point. At first boot, I see that there is a Windows folder when browsing network. Since there is no operating system present, besides the usb that I boot from, should there be a Windows network folder? I am using a local ISP (and won't be much longer because I am very paranoid at this point) and I want to make sure all is ok before I put my new hard drive in and install Ubuntu. Any help would be appreciated. Also, I want to thank Ubuntu and the community for giving people an alternative.

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  • How do I properly implement zooming in my game?

    - by Rudy_TM
    I'm trying to implement a zoom feature but I have a problem. I am zooming in and out a camera with a pinch gesture, I update the camera each time in the render, but my sprites keep their original position and don't change with the zoom in or zoom out. The Libraries are from libgdx. What am I missing? private void zoomIn() { ((OrthographicCamera)this.stage.getCamera()).zoom += .01; } public boolean pinch(Vector2 arg0, Vector2 arg1, Vector2 arg2, Vector2 arg3) { // TODO Auto-generated method stub zoomIn(); return false; } public void render(float arg0) { this.gl.glClear(GL10.GL_DEPTH_BUFFER_BIT | GL10.GL_COLOR_BUFFER_BIT); ((OrthographicCamera)this.stage.getCamera()).update(); this.stage.draw(); } public boolean touchDown(int arg0, int arg1, int arg2) { this.stage.toStageCoordinates(arg0, arg1, point); Actor actor = this.stage.hit(point.x, point.y); if(actor instanceof Group) { ((LevelSelect)((Group) actor).getActors().get(0)).touched(); } return true; } Zoom In Zoom Out

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  • how does HDR work?

    - by dotminic
    I'm trying to understand what HDR is and how it works. I understand the basic concepts and have an slight idea of how it is implemented with D3D/hlsl. However it's still pretty foggy. Say I'm rendering a sphere with a texture of the earth and a small point list of vertices to act as stars, how would I render this in HDR ? Here are a few things I'm confused about: I'm guessing, I can't use just any basic image format for the texture as the values would be limited to [0, 255] and clamped to [0, 1] in a shader. Same goes for the back buffer, I take it the format needs to be a float point format ? What are the other steps involved ? Surely there has to be more than just using floating point formats to render to a render target and then apply some bloom as a post process ? (considering the output will be 8bpp anyway) Basically, what are the steps for HDR ? How does it work ? I can't seem to find any good papers / articles that describe the process, other than this one, but it seems to skim over the basics a little, so it's confusing.

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  • Rotating object around moving object/player in 2D

    - by Boston
    I am trying to implement a camera which rotates around the world around the player. I have found many solutions online to the task of rotating an object about the origin, or about an arbitrary point. The procedure seems to be to translate the point to be rotated about to the origin, perform the rotation, translate back, then draw. I have gotten this working for rotation around the origin as well as for a fixed point. Rotation of objects around the player works as well, provided the player does not move. However, if the objects are rotated around the player by some non-zero degree, if the player moves after the rotation it causes the rotated objects to move as well. I probably have done a poor job explaining this so here's an image: http://i.imgur.com/1n63iWR.gif And here's the code for the behavior: renderx = (Ox - Px)*cos(camAngle) - (Oy - Py)*sin(camAngle) + Px; rendery = (Ox - Px)*sin(camAngle) + (Oy - Py)*cos(camAngle) + Py; Where (Ox,Oy) is the actual position of the object to be rotated and (Px,Py) is the actual position of the player. Any ideas? I am using C++ with SDL2.0.

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  • Is this one network or two networks?

    - by colemik
    I have this simple question and really don't know the answer. Does the drawing below show one network or two networks? This is a question about the definition of a network from the OSI / TCP/IP model point of view: From one point of view, those are two L2 networks connected with a bridge. From another point of view, this is one L3 network, that can have a common L3 address space (like 10.1.1.0). PS If this question is too dumb, please move it to Superuser.

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  • Function for building an isosurface (a sphere cut by planes)

    - by GameDevEnthusiast
    I want to build an octree over a quarter of a sphere (for debugging and testing). The octree generator relies on the AIsosurface interface to compute the density and normal at any given point in space. For example, for a full sphere the corresponding code is: // returns <0 if the point is inside the solid virtual float GetDensity( float _x, float _y, float _z ) const override { Float3 P = Float3_Set( _x, _y, _z ); Float3 v = Float3_Subtract( P, m_origin ); float l = Float3_LengthSquared( v ); float d = Float_Sqrt(l) - m_radius; return d; } // estimates the gradient at the given point virtual Float3 GetNormal( float _x, float _y, float _z ) const override { Float3 P = Float3_Set( _x, _y, _z ); float d = this->AIsosurface::GetDensity( P ); float Nx = this->GetDensity( _x + 0.001f, _y, _z ) - d; float Ny = this->GetDensity( _x, _y + 0.001f, _z ) - d; float Nz = this->GetDensity( _x, _y, _z + 0.001f ) - d; Float3 N = Float3_Normalized( Float3_Set( Nx, Ny, Nz ) ); return N; } What is a nice and fast way to compute those values when the shape is bounded by a low number of half-spaces?

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  • overloaded stream insertion operator with a vector

    - by Julz
    hi, i'm trying to write an overloaded stream insertion operator for a class who's only member is a vector. i dont really know what i'm doing. (lets make that clear) it's a vector of "Points" which is a struct containing two doubles. i figure what i want is to insert user input (a bunch of doubles) into a stream that i then send to a modifier method? i keep working off other stream insertion examples such as... std::ostream& operator<< (std::ostream& o, Fred const& fred) { return o << fred.i_; } but when i try a similar..... istream & operator >> (istream &inStream, Polygon &vertStr) { inStream >> ws; inStream >> vertStr.vertices; return inStream; } i get an error "no match for operator etc etc. if i leave off the .vertices it compiles but i figure it's not right? (vertices is the name of my vector ) and even if it is right, i dont actually know what syntax to use in my driver to use it? also not %100 on what my modifier method needs to look like. here's my Polygon class //header #ifndef POLYGON_H #define POLYGON_H #include "Segment.h" #include <vector> class Polygon { friend std::istream & operator >> (std::istream &inStream, Polygon &vertStr); public: //Constructor Polygon(const Point &theVerts); //Default Constructor Polygon(); //Copy Constructor Polygon(const Polygon &polyCopy); //Accessor/Modifier methods inline std::vector<Point> getVector() const {return vertices;} //Return number of Vector elements inline int sizeOfVect() const {return (int) vertices.capacity();} //add Point elements to vector inline void setVertices(const Point &theVerts){vertices.push_back (theVerts);} private: std::vector<Point> vertices; }; #endif //Body using namespace std; #include "Polygon.h" // Constructor Polygon::Polygon(const Point &theVerts) { vertices.push_back (theVerts); } //Copy Constructor Polygon::Polygon(const Polygon &polyCopy) { vertices = polyCopy.vertices; } //Default Constructor Polygon::Polygon(){} istream & operator >> (istream &inStream, Polygon &vertStr) { inStream >> ws; inStream >> vertStr; return inStream; } any help greatly appreciated, sorry to be so vague, a lecturer has just kind of given us a brief example of stream insertion then left us on our own thanks. oh i realise there are probably many other problems that need fixing

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  • Any tool to make git build every commit to a branch in a seperate repository?

    - by Wayne
    A git tool that meets the specs below is needed. Does one already exists? If not, I will create a script and make it available on GitHub for others to use or contribute. Is there a completely different and better way to solve the need to build/test every commit to a branch in a git repository? Not just to the latest but each one back to a certain staring point. Background: Our development environment uses a separate continuous integration server which is wonderful. However, it is still necessary to do full builds locally on each developer's PC to make sure the commit won't "break the build" when pushed to the CI server. Unfortunately, with auto unit tests, those build force the developer to wait 10 or 15 minutes for a build every time. To solve this we have setup a "mirror" git repository on each developer PC. So we develop in the main repository but anytime a local full build is needed. We run a couple commands in a in the mirror repository to fetch, checkout the commit we want to build, and build. It's works extremely lovely so we can continue working in the main one with the build going in parallel. There's only one main concern now. We want to make sure every single commit builds and tests fine. But we often get busy and neglect to build several fresh commits. Then if it the build fails you have to do a bisect or manually figure build each interim commit to figure out which one broke. Requirements for this tool. The tool will look at another repo, origin by default, fetch and compare all commits that are in branches to 2 lists of commits. One list must hold successfully built commits and the other lists commits that failed. It identifies any commit or commits not yet in either list and begins to build them in a loop in the order that they were committed. It stops on the first one that fails. The tool appropriately adds each commit to either the successful or failed list after it as attempted to build each one. The tool will ignore any "legacy" commits which are prior to the oldest commit in the success list. This logic makes the starting point possible in the next point. Starting Point. The tool building a specific commit so that, if successful it gets added to the success list. If it is the earliest commit in the success list, it becomes the "starting point" so that none of the commits prior to that are examined for builds. Only linear tree support? Much like bisect, this tool works best on a commit tree which is, at least from it's starting point, linear without any merges. That is, it should be a tree which was built and updated entirely via rebase and fast forward commits. If it fails on one commit in a branch it will stop without building the rest that followed after that one. Instead if will just move on to another branch, if any. The tool must do these steps once by default but allow a parameter to loop with an option to set how many seconds between loops. Other tools like Hudson or CruiseControl could do more fancy scheduling options. The tool must have good defaults but allow optional control. Which repo? origin by default. Which branches? all of them by default. What tool? by default an executable file to be provided by the user named "buildtest", "buildtest.sh" "buildtest.cmd", or buildtest.exe" in the root folder of the repository. Loop delay? run once by default with option to loop after a number of seconds between iterations.

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  • How to use Boost 1.41.0 graph layout algorithmes

    - by daniil-k
    Hi I have problem using boost graph layout algorithmes. boost verision 1_41_0 mingw g++ 4.4.0. So there are issues I have encountered Can you suggest me with them? The function fruchterman_reingold_force_directed_layout isn't compiled. The kamada_kawai_spring_layout compiled but program crashed. Boost documentation to layout algorithms is wrong, sample to fruchterman_reingold_force_directed_layout isn't compiled. This is my example. To use function just uncomment one. String 60, 61, 63. #include <boost/config.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graph_utility.hpp> #include <boost/graph/simple_point.hpp> #include <boost/property_map/property_map.hpp> #include <boost/graph/circle_layout.hpp> #include <boost/graph/fruchterman_reingold.hpp> #include <boost/graph/kamada_kawai_spring_layout.hpp> #include <iostream> //typedef boost::square_topology<>::point_difference_type Point; typedef boost::square_topology<>::point_type Point; struct VertexProperties { std::size_t index; Point point; }; struct EdgeProperty { EdgeProperty(const std::size_t &w):weight(w) {} double weight; }; typedef boost::adjacency_list<boost::listS, boost::listS, boost::undirectedS, VertexProperties, EdgeProperty > Graph; typedef boost::property_map<Graph, std::size_t VertexProperties::*>::type VertexIndexPropertyMap; typedef boost::property_map<Graph, Point VertexProperties::*>::type PositionMap; typedef boost::property_map<Graph, double EdgeProperty::*>::type WeightPropertyMap; typedef boost::graph_traits<Graph>::vertex_descriptor VirtexDescriptor; int main() { Graph graph; VertexIndexPropertyMap vertexIdPropertyMap = boost::get(&VertexProperties::index, graph); for (int i = 0; i < 3; ++i) { VirtexDescriptor vd = boost::add_vertex(graph); vertexIdPropertyMap[vd] = i + 2; } boost::add_edge(boost::vertex(1, graph), boost::vertex(0, graph), EdgeProperty(5), graph); boost::add_edge(boost::vertex(2, graph), boost::vertex(0, graph), EdgeProperty(5), graph); std::cout << "Vertices\n"; boost::print_vertices(graph, vertexIdPropertyMap); std::cout << "Edges\n"; boost::print_edges(graph, vertexIdPropertyMap); PositionMap positionMap = boost::get(&VertexProperties::point, graph); WeightPropertyMap weightPropertyMap = boost::get(&EdgeProperty::weight, graph); boost::circle_graph_layout(graph, positionMap, 100); // boost::fruchterman_reingold_force_directed_layout(graph, positionMap, boost::square_topology<>()); boost::kamada_kawai_spring_layout(graph, positionMap, weightPropertyMap, boost::square_topology<>(), boost::side_length<double>(10), boost::layout_tolerance<>(), 1, vertexIdPropertyMap); std::cout << "Coordinates\n"; boost::graph_traits<Graph>::vertex_iterator i, end; for (boost::tie(i, end) = boost::vertices(graph); i != end; ++i) { std::cout << "ID: (" << vertexIdPropertyMap[*i] << ") x: " << positionMap[*i][0] << " y: " << positionMap[*i][1] << "\n"; } return 0; }

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  • setTimeout in javascript not giving browser 'breathing room'

    - by C Bauer
    Alright, I thought I had this whole setTimeout thing perfect but I seem to be horribly mistaken. I'm using excanvas and javascript to draw a map of my home state, however the drawing procedure chokes the browser. Right now I'm forced to pander to IE6 because I'm in a big organisation, which is probably a large part of the slowness. So what I thought I'd do is build a procedure called distributedDrawPolys (I'm probably using the wrong word there, so don't focus on the word distributed) which basically pops the polygons off of a global array in order to draw 50 of them at a time. This is the method that pushes the polygons on to the global array and runs the setTimeout: for (var x = 0; x < polygon.length; x++) { coordsObject.push(polygon[x]); fifty++; if (fifty > 49) { timeOutID = setTimeout(distributedDrawPolys, 5000); fifty = 0; } } I put an alert at the end of that method, it runs in practically a second. The distributed method looks like: function distributedDrawPolys() { if (coordsObject.length > 0) { for (x = 0; x < 50; x++) { //Only do 50 polygons var polygon = coordsObject.pop(); var coordinate = polygon.selectNodes("Coordinates/point"); var zip = polygon.selectNodes("ZipCode"); var rating = polygon.selectNodes("Score"); if (zip[0].text.indexOf("HH") == -1) { var lastOriginCoord = []; for (var y = 0; y < coordinate.length; y++) { var point = coordinate[y]; latitude = shiftLat(point.getAttribute("lat")); longitude = shiftLong(point.getAttribute("long")); if (y == 0) { lastOriginCoord[0] = point.getAttribute("long"); lastOriginCoord[1] = point.getAttribute("lat"); } if (y == 1) { beginPoly(longitude, latitude); } if (y > 0) { if (translateLongToX(longitude) > 0 && translateLongToX(longitude) < 800 && translateLatToY(latitude) > 0 && translateLatToY(latitude) < 600) { drawPolyPoint(longitude, latitude); } } } y = 0; if (zip[0].text != targetZipCode) { if (rating[0] != null) { if (rating[0].text == "Excellent") { endPoly("rgb(0,153,0)"); } else if (rating[0].text == "Good") { endPoly("rgb(153,204,102)"); } else if (rating[0].text == "Average") { endPoly("rgb(255,255,153)"); } } else { endPoly("rgb(255,255,255)"); } } else { endPoly("rgb(255,0,0)"); } } } } Ugh I don't know if that is properly formatted, I ended up with an extra bracket < So I thought the setTimeout method would allow the site to draw the polygons in groups so the users would be able to interact with the page while it was still drawing. What am I doing wrong here?

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  • Why isn't my algorithm for find the biggest and smallest inputs working?

    - by Matt Ellen
    I have started a new job, and with it comes a new language: Ironpython. Thankfully a good language :D Before starting I got to grips with Python on the whole, but that was only a week's worth of learning. Now I'm writing actual code. I've been charged with writing an algorithm that finds the best input parameter to collect data with. The basic algorithm is (as I've been instructed): Set the input parameter to a good guess Start collecting data When data is available stop collecting find the highest point If the point before this (i.e. for the previous parameter value) was higher and the point before that was lower then we've found the max otherwise the input parameter is increased by the initial guess. goto 2 If the max is found then the min needs to be found. To do this the algorithm carries on increasing the input, but by 1/10 of the max, until the current point is greater than the previous point and the point before that is also greater. Once the min is found then the algorithm stops. Currently I have a simplified data generator outputting the sin of the input, so that I know that the min value should be PI and the max value should be PI/2 The main Python code looks like this (don't worry, this is just for my edification, I don't write real code like this): import sys sys.path.append(r"F:\Programming Source\C#\PythonHelp\PythonHelp\bin\Debug") import clr clr.AddReferenceToFile("PythonHelpClasses.dll") import PythonHelpClasses from PHCStruct import Helper from System import Math helper = Helper() def run(): b = PythonHelpClasses.Executor() a = PythonHelpClasses.HasAnEvent() b.Input = 0.0 helper.__init__() def AnEventHandler(e): b.Stop() h = helper h.lastLastVal, h.lastVal, h.currentVal = h.lastVal, h.currentVal, e.Number if h.lastLastVal < h.lastVal and h.currentVal < h.lastVal and h.NotPast90: h.NotPast90 = False h.bestInput = h.lastInput inputInc = 0.0 if h.NotPast90: inputInc = Math.PI/10.0 else: inputInc = h.bestInput/10.0 if h.lastLastVal > h.lastVal and h.currentVal > h.lastVal and h.NotPast180: h.NotPast180 = False if h.NotPast180: h.lastInput, b.Input = b.Input, b.Input + inputInc b.Start(a) else: print "Best input:", h.bestInput print "Last input:", h.lastInput b.Stop() a.AnEvent += AnEventHandler b.Start(a) PHCStruct.py: class Helper(): def __init__(self): self.currentVal = 0 self.lastVal = 0 self.lastLastVal = 0 self.NotPast90 = True self.NotPast180 = True self.bestInput = 0 self.lastInput = 0 PythonHelpClasses has two small classes I wrote in C# before I realised how to do it in Ironpython. Executor runs a delegate asynchronously while it's running member is true. The important code: public void Start(HasAnEvent hae) { running = true; RunDelegate r = new RunDelegate(hae.UpdateNumber); AsyncCallback ac = new AsyncCallback(UpdateDone); IAsyncResult ar = r.BeginInvoke(Input, ac, null); } public void Stop() { running = false; } public void UpdateDone(IAsyncResult ar) { RunDelegate r = (RunDelegate)((AsyncResult)ar).AsyncDelegate; r.EndInvoke(ar); if (running) { AsyncCallback ac = new AsyncCallback(UpdateDone); IAsyncResult ar2 = r.BeginInvoke(Input, ac, null); } } HasAnEvent has a function that generates the sin of its input and fires an event with that result as its argument. i.e.: public void UpdateNumber(double val) { AnEventArgs e = new AnEventArgs(Math.Sin(val)); System.Threading.Thread.Sleep(1000); if (null != AnEvent) { AnEvent(e); } } The sleep is in there just to slow things down a bit. The problem I am getting is that the algorithm is not coming up with the best input being PI/2 and the final input being PI, but I can't see why. Also the best and final inputs are different each time I run the programme. Can anyone see why? Also when the algorithm terminates the best and final inputs are printed to the screen multiple times, not just once. Can someone explain why?

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  • overloaded stream insetion operator with a vector

    - by julz666
    hi, i'm trying to write an overloaded stream insertion operator for a class who's only member is a vector. i dont really know what i'm doing. (lets make that clear) it's a vector of "Points" which is a struct containing two doubles. i figure what i want is to insert user input (a bunch of doubles) into a stream that i then send to a modifier method? i keep working off other stream insertion examples such as... std::ostream& operator<< (std::ostream& o, Fred const& fred) { return o << fred.i_; } but when i try a similar..... istream & operator >> (istream &inStream, Polygon &vertStr) { inStream >> ws; inStream >> vertStr.vertices; return inStream; } i get an error "no match for operator etc etc. if i leave off the .vertices it compiles but i figure it's not right? (vertices is the name of my vector ) and even if it is right, i dont actually know what syntax to use in my driver to use it? also not %100 on what my modifier method needs to look like. here's my Polygon class //header #ifndef POLYGON_H #define POLYGON_H #include "Segment.h" #include <vector> class Polygon { friend std::istream & operator >> (std::istream &inStream, Polygon &vertStr); public: //Constructor Polygon(const Point &theVerts); //Default Constructor Polygon(); //Copy Constructor Polygon(const Polygon &polyCopy); //Accessor/Modifier methods inline std::vector<Point> getVector() const {return vertices;} //Return number of Vector elements inline int sizeOfVect() const {return (int) vertices.capacity();} //add Point elements to vector inline void setVertices(const Point &theVerts){vertices.push_back (theVerts);} private: std::vector<Point> vertices; }; #endif //Body using namespace std; #include "Polygon.h" // Constructor Polygon::Polygon(const Point &theVerts) { vertices.push_back (theVerts); } //Copy Constructor Polygon::Polygon(const Polygon &polyCopy) { vertices = polyCopy.vertices; } //Default Constructor Polygon::Polygon(){} istream & operator >> (istream &inStream, Polygon &vertStr) { inStream >> ws; inStream >> vertStr; return inStream; } any help greatly appreciated, sorry to be so vague, a lecturer has just kind of given us a brief example of stream insertion then left us on our own thanks. oh i realise there are probably many other problems that need fixing

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  • Memory management in iphone cocos2d

    - by muthu
    i am iphone developer very new to this field....i am developing a ebook app in iphone using cocos2d...i use more than 150 images(i guess) the problem while turning from one page to another images get hanged randomly...... i tried this also [[TextureMgr sharedTextureMgr] removeAllTextures]; but went in vain...i guess the the problem is with the memory.....this my coding for all the pages -(id)init { if( (self=[super init] )) { self.isTouchEnabled = YES; [SimpleAudioEngine sharedEngine]; NSLog(@"b4 cover"); Sprite *bg1 = [Sprite spriteWithFile:@"a.jpg"]; bg1.anchorPoint = CGPointZero; [self addChild:bg1 z:-1]; once = TRUE; soundId = [[SimpleAudioEngine sharedEngine] playEffect:@".mp3"]; } return self; } -(void) transitionfront:(id) sender { [[SimpleAudioEngine sharedEngine] stopEffect:soundId]; soundId1 = [[SimpleAudioEngine sharedEngine] playEffect:@"page_turn.mp3"]; flip = [[Sprite spriteWithFile:@"a.jpg"] retain]; [self addChild: flip z:1]; [flip setPosition:ccp(160,240)]; Animation* animation1 = [Animation animationWithName:@"Page1" delay:0.09]; for( int i=1;i<4;i++) [animation1 addFrameWithFilename: [NSString stringWithFormat:@".jpg", i]]; id action = [Animate actionWithAnimation: animation1]; //id action = [RepeatForever actionWithAction:[Animate actionWithAnimation: animation1]]; [flip runAction:action]; [NSTimer scheduledTimerWithTimeInterval:0.3 target:self selector:@selector(moveforward) userInfo:nil repeats:NO]; } -(void) moveforward { [[SimpleAudioEngine sharedEngine] stopEffect:soundId1]; [[Director sharedDirector] replaceScene: [ [Scene node] addChild: [nextpage node] z:0] ]; } -(void) transitionback:(id) sender { [[SimpleAudioEngine sharedEngine] stopEffect:soundId]; soundId1 = [[SimpleAudioEngine sharedEngine] playEffect:@".mp3"]; flip = [[Sprite spriteWithFile:@".jpg"] retain]; [self addChild: flip z:1]; [flip setPosition:ccp(160,240)]; Animation* animation1 = [Animation animationWithName:@"Page1" delay:0.09]; for( int i=3;i>0;i--) [animation1 addFrameWithFilename: [NSString stringWithFormat:@".jpg", i]]; id action = [Animate actionWithAnimation: animation1]; //id action = [RepeatForever actionWithAction:[Animate actionWithAnimation: animation1]]; [flip runAction:action]; [NSTimer scheduledTimerWithTimeInterval:0.3 target:self selector:@selector(movebackward) userInfo:nil repeats:NO]; } -(void) movebackward{ //[[SimpleAudioEngine sharedEngine]stopEffect:@".mp3"]; [[Director sharedDirector]replaceScene:[[Scene node]addChild:[b4page node] z:0]]; } -(void) glossary :(id) sender { [[SimpleAudioEngine sharedEngine]stopEffect:soundId]; [[Director sharedDirector]replaceScene:[[Scene node]addChild:[ node] z:0]]; } -(BOOL)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event { UITouch *touch = [touches anyObject]; CGPoint cocosTouchPoint = [touch locationInView: [touch view]]; CGPoint point = [[Director sharedDirector] convertToGL:cocosTouchPoint]; NSLog(@"pointx: %f pointy:%f", point.x, point.y); // Was a tab touched, if so, which one... if (CGRectContainsPoint(CGRectMake(220, 0, 100, 70), point)) { if(once) { NSLog(@"enterred page1"); [self transitionfront:nil]; once = FALSE; } } if (CGRectContainsPoint(CGRectMake(0,0,60,60), point)) { if(once) { NSLog(@"enterred cover"); [self transitionback:nil]; once = FALSE; } } if (CGRectContainsPoint(CGRectMake(100, 15, 30, 30), point)) { if(once){ [self glossary :nil]; once = FALSE; } } return kEventHandled; } -(void)playEffect:(NSString*)sound{ if(effectPlayer!=nil){ [effectPlayer release]; } NSURL *url = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:sound ofType:@"mp3"]]; effectPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil]; [effectPlayer setDelegate:self]; [effectPlayer play]; } -(void)stopEffect { [effectPlayer stop]; } -(void) dealloc{ [super dealloc]; } do pls help me........ do give me a exact coding this is the err..... *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSCFDictionary setObject:forKey:]: attempt to insert nil value (key: aesop.mp3)' 2010-05-27 10:43:09.834 abc[276:20b] Stack: ( 11674715, 2476006971, 11758651, 11758490, 5126917, 660698, 660881, 661061, 131577, 448857, 120432, 153433, 630890, 23694899, 23603228, 23630005, 47120081, 11459456, 11455560, 47114125, 47114322, 23633923, 9928, 9814 )

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  • how to make a div(black border,and on the google-maps) panel drop-disable,thanks

    - by zjm1126
    the black div is used to panel,so it can not be droppable. <!DOCTYPE html PUBLIC "-//WAPFORUM//DTD XHTML Mobile 1.0//EN" "http://www.wapforum.org/DTD/xhtml-mobile10.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" > <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <meta name="viewport" content="width=device-width,minimum-scale=0.3,maximum-scale=5.0,user-scalable=yes"> </head> <body onload="initialize()" onunload="GUnload()"> <style type="text/css"> *{ margin:0; padding:0; } .container{ padding:10px; width:50px; height:50px; border:5px solid black; } </style> <!--<div style="width:100px;height:100px;background:blue;"> </div>--> <div id="map_canvas" style="width: 500px; height: 300px;"></div> <!-- <div class=b style="width: 20px; height: 20px;background:red;position:absolute;left:700px;top:200px;"></div> <div class=b style="width: 20px; height: 20px;background:red;position:absolute;left:700px;top:200px;"></div> <div class=b style="width: 20px; height: 20px;background:red;position:absolute;left:700px;top:200px;"></div> <div class=b style="width: 20px; height: 20px;background:red;position:absolute;left:700px;top:200px;"></div> <div class=b style="width: 20px; height: 20px;background:red;position:absolute;left:700px;top:200px;"></div> --> <script src="jquery-1.4.2.js" type="text/javascript"></script> <script src="jquery-ui-1.8rc3.custom.min.js" type="text/javascript"></script> <script src="http://maps.google.com/maps?file=api&amp;v=2&amp;key=ABQIAAAA-7cuV3vqp7w6zUNiN_F4uBRi_j0U6kJrkFvY4-OX2XYmEAa76BSNz0ifabgugotzJgrxyodPDmheRA&sensor=false"type="text/javascript"></script> <script type="text/javascript"> var aFn; //********** function initialize() { if (GBrowserIsCompatible()) { //************ function a() { } a.prototype = new GControl(); a.prototype.initialize = function(map) { var container = document.createElement("div"); var a=''; for(i=0;i<5;i++){ a+='<div class=b style="width: 20px; height: 20px;background:red;position:absolute;"></div>' } $(container).addClass('container'); $(container).droppable( 'destroy' ).css('z-index','2700') $(map.getContainer()).append($(container).append(a)); return container; } a.prototype.getDefaultPosition = function() { return new GControlPosition(G_ANCHOR_TOP_LEFT, new GSize(7, 7)); } //************ var map = new GMap2(document.getElementById("map_canvas")); map.addControl(new a()); var center=new GLatLng(39.9493, 116.3975); map.setCenter(center, 13); aFn=function(x,y){ var point =new GPoint(x,y) point = map.fromContainerPixelToLatLng(point); //console.log(point.x+" "+point.y) map.addOverlay(new GMarker(point)); } $(".b").draggable({}); $("#map_canvas").droppable({ drop: function(event,ui) { //console.log(ui.offset.left+' '+ui.offset.top) aFn(ui.offset.left+10,ui.offset.top+10); ui.draggable.remove(); } }); } } //************* </script> </body> </html>

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  • Can someone explain this color wheel code to me?

    - by user1869438
    I just started doing java and i need some help with understanding this code. I got it from a this website. This is supposed to be code for a color wheel but i don't really understand how it works, especially the final ints STEPS and SLICES. import java.awt.Color; import objectdraw.*; public class ColorWheel extends WindowController { private double brightness; private Text text; private FilledRect swatch; private Location center; private int size; private FilledRect brightnessOverlay; private static final int SLICES = 96; private static final int STEPS = 16; public void begin() { canvas.setBackground(Color.BLACK); brightness = 1.; size = Math.min(canvas.getWidth(), canvas.getHeight() - 20); center = new Location(canvas.getWidth() / 2, size / 2); for(int j = STEPS; j >= 1; j--) { int arcSize = size * j / STEPS; int x = center.getX() - arcSize / 2; int y = center.getY() - arcSize / 2; for(int i = 0; i < SLICES; i++) { Color c = Color.getHSBColor((float)i / SLICES, (float)j / STEPS, (float)brightness); new FilledArc(x, y, arcSize, arcSize, i * 360. / SLICES, 360. / SLICES + .5, c, canvas); } } swatch = new FilledRect(0, canvas.getHeight() - 20, canvas.getWidth(), 20, Color.BLACK, canvas); brightnessOverlay = new FilledRect(0, 0, canvas.getWidth(), canvas.getHeight() - 20, new Color(0, 0, 0, 0), canvas); text = new Text("", canvas.getWidth() / 2, canvas.getHeight() - 18, canvas); text.setAlignment(Text.CENTER, Text.TOP); text.setBold(true); } public void onMouseDrag(Location point) { brightness = (canvas.getHeight() - point.getY()) / (double)(canvas.getHeight()); if(brightness < 0) { brightness = 0; } else if(brightness > 1) { brightness = 1; } if(brightness < .5) { text.setColor(Color.WHITE); } else { text.setColor(Color.BLACK); } brightnessOverlay.setColor(new Color(0f, 0f, 0f, (float)(1 - brightness))); } public void onMouseMove(Location point) { double saturation = 2 * center.distanceTo(point) / size; if(saturation > 1) { text.setText(""); swatch.setColor(Color.BLACK); return; } double hue = -Math.atan2(point.getY() - center.getY(), point.getX() - center.getX()) / (2 * Math.PI); if(hue < 0) { hue += 1; } swatch.setColor(Color.getHSBColor((float)hue, (float)saturation, (float)brightness)); text.setText("Color.getHSBColor(" + Text.formatDecimal(hue, 2) + "f, " + Text.formatDecimal(saturation, 2) + "f, " + Text.formatDecimal(brightness, 2) + "f)"); } }

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  • Effective optimization strategies on modern C++ compilers

    - by user168715
    I'm working on scientific code that is very performance-critical. An initial version of the code has been written and tested, and now, with profiler in hand, it's time to start shaving cycles from the hot spots. It's well-known that some optimizations, e.g. loop unrolling, are handled these days much more effectively by the compiler than by a programmer meddling by hand. Which techniques are still worthwhile? Obviously, I'll run everything I try through a profiler, but if there's conventional wisdom as to what tends to work and what doesn't, it would save me significant time. I know that optimization is very compiler- and architecture- dependent. I'm using Intel's C++ compiler targeting the Core 2 Duo, but I'm also interested in what works well for gcc, or for "any modern compiler." Here are some concrete ideas I'm considering: Is there any benefit to replacing STL containers/algorithms with hand-rolled ones? In particular, my program includes a very large priority queue (currently a std::priority_queue) whose manipulation is taking a lot of total time. Is this something worth looking into, or is the STL implementation already likely the fastest possible? Along similar lines, for std::vectors whose needed sizes are unknown but have a reasonably small upper bound, is it profitable to replace them with statically-allocated arrays? I've found that dynamic memory allocation is often a severe bottleneck, and that eliminating it can lead to significant speedups. As a consequence I'm interesting in the performance tradeoffs of returning large temporary data structures by value vs. returning by pointer vs. passing the result in by reference. Is there a way to reliably determine whether or not the compiler will use RVO for a given method (assuming the caller doesn't need to modify the result, of course)? How cache-aware do compilers tend to be? For example, is it worth looking into reordering nested loops? Given the scientific nature of the program, floating-point numbers are used everywhere. A significant bottleneck in my code used to be conversions from floating point to integers: the compiler would emit code to save the current rounding mode, change it, perform the conversion, then restore the old rounding mode --- even though nothing in the program ever changed the rounding mode! Disabling this behavior significantly sped up my code. Are there any similar floating-point-related gotchas I should be aware of? One consequence of C++ being compiled and linked separately is that the compiler is unable to do what would seem to be very simple optimizations, such as move method calls like strlen() out of the termination conditions of loop. Are there any optimization like this one that I should look out for because they can't be done by the compiler and must be done by hand? On the flip side, are there any techniques I should avoid because they are likely to interfere with the compiler's ability to automatically optimize code? Lastly, to nip certain kinds of answers in the bud: I understand that optimization has a cost in terms of complexity, reliability, and maintainability. For this particular application, increased performance is worth these costs. I understand that the best optimizations are often to improve the high-level algorithms, and this has already been done.

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  • OpenGL FrameBuffer Objects weird behavior

    - by Ben Jones
    My algorithm is this: Render the scene to a FBO with shadow mapping from multiple locations Render the scene to the screen with shadow mapping ...black magic that I still have to imlement... Combine the samples from step 1 with the image from step 2 I'm trying to debug steps 1 and 2 and am coming across STRANGE behavior. My algorithm for each shadow mapped pass is: render the scene to a FBO connected to a depth array texture from the POV of each light render the scene from the viewpoint and use vertex/frag shaders to compare the depths When I run my algorithm this way: render from point to FBO render from point to screen glutSwapBuffers() The normal vectors in the screen pass appear to be incorrect (inverted possibly). I'm pretty sure that's the issue because my diffuse lighting calculation is incorrect, but the material colors are correct, and the shadows appear in the correct places. So, it seems like the only thing that could be the culprit is the normals. However if I do render from point to FBO render from point to Screen glutSwapBuffers() //wrong here render from point to Screen glutSwapBuffers() the second pass is correct. I assume there's a problem with my framebuffer calls. Can anyone see what the problem is from the log below? Its from a bugle trace grepped for 'buffer' with a few edits to make it a little more clear. Thanks! [INFO] trace.call: glGenFramebuffersEXT(1, 0xdfeb90 - { 1 }) [INFO] trace.call: glGenFramebuffersEXT(1, 0xdfebac - { 2 }) [INFO] trace.call: glBindFramebufferEXT(GL_FRAMEBUFFER, 1) [INFO] trace.call: glDrawBuffer(GL_NONE) [INFO] trace.call: glReadBuffer(GL_NONE) [INFO] trace.call: glBindFramebufferEXT(GL_FRAMEBUFFER, 0) //start render to FBO [INFO] trace.call: glBindFramebufferEXT(GL_FRAMEBUFFER, 2) [INFO] trace.call: glReadBuffer(GL_NONE) [INFO] trace.call: glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, 2, 0) [INFO] trace.call: glFramebufferTexture2DEXT(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, 3, 0) [INFO] trace.call: glDrawBuffer(GL_COLOR_ATTACHMENT0) //bind to the FBO attached to a depth tex array for shadows [INFO] trace.call: glBindFramebufferEXT(GL_FRAMEBUFFER, 1) [INFO] trace.call: glFramebufferTextureLayerARB(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, 1, 0, 0) [INFO] trace.call: glClear(GL_DEPTH_BUFFER_BIT) //draw geometry //bind to the FBO I want the shadow mapped image rendered to [INFO] trace.call: glBindFramebufferEXT(GL_FRAMEBUFFER, 2) [INFO] trace.call: glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) //draw geometry //draw to screen pass //again shadow mapping FBO [INFO] trace.call: glBindFramebufferEXT(GL_FRAMEBUFFER, 1) [INFO] trace.call: glFramebufferTextureLayerARB(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, 1, 0, 0) [INFO] trace.call: glClear(GL_DEPTH_BUFFER_BIT) //draw geometry //bind to the screen [INFO] trace.call: glBindFramebufferEXT(GL_FRAMEBUFFER, 0) [INFO] trace.call: glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) //finished, swap buffers [INFO] trace.call: glXSwapBuffers(0xd5fc10, 0x05800002) //INCORRECT OUTPUT //second try at render to screen: [INFO] trace.call: glBindFramebufferEXT(GL_FRAMEBUFFER, 1) [INFO] trace.call: glFramebufferTextureLayerARB(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, 1, 0, 0) [INFO] trace.call: glClear(GL_DEPTH_BUFFER_BIT) //draw geometry [INFO] trace.call: glBindFramebufferEXT(GL_FRAMEBUFFER, 0) [INFO] trace.call: glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT) draw geometry [INFO] trace.call: glXSwapBuffers(0xd5fc10, 0x05800002) //correct output

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  • Smooth animation using MatrixTransform?

    - by Mattias Konradsson
    I'm trying to do an Matrix animation where I both scale and transpose a canvas at the same time. The only approach I found was using a MatrixTransform and MatrixAnimationUsingKeyFrames. Since there doesnt seem to be any interpolation for matrices built in (only for path/rotate) it seems the only choice is to try and build the interpolation and DiscreteMatrixKeyFrame's yourself. I did a basic implementation of this but it isnt exactly smooth and I'm not sure if this is the best way and how to handle framerates etc. Anyone have suggestions for improvement? Here's the code: MatrixAnimationUsingKeyFrames anim = new MatrixAnimationUsingKeyFrames(); int duration = 1; anim.KeyFrames = Interpolate(new Point(0, 0), centerPoint, 1, factor,100,duration); this.matrixTransform.BeginAnimation(MatrixTransform.MatrixProperty, anim,HandoffBehavior.Compose); public MatrixKeyFrameCollection Interpolate(Point startPoint, Point endPoint, double startScale, double endScale, double framerate,double duration) { MatrixKeyFrameCollection keyframes = new MatrixKeyFrameCollection(); double steps = duration * framerate; double milliSeconds = 1000 / framerate; double timeCounter = 0; double diffX = Math.Abs(startPoint.X- endPoint.X); double xStep = diffX / steps; double diffY = Math.Abs(startPoint.Y - endPoint.Y); double yStep = diffY / steps; double diffScale= Math.Abs(startScale- endScale); double scaleStep = diffScale / steps; if (endPoint.Y < startPoint.Y) { yStep = -yStep; } if (endPoint.X < startPoint.X) { xStep = -xStep; } if (endScale < startScale) { scaleStep = -scaleStep; } Point currentPoint = new Point(); double currentScale = startScale; for (int i = 0; i < steps; i++) { keyframes.Add(new DiscreteMatrixKeyFrame(new Matrix(currentScale, 0, 0, currentScale, currentPoint.X, currentPoint.Y), KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(timeCounter)))); currentPoint.X += xStep; currentPoint.Y += yStep; currentScale += scaleStep; timeCounter += milliSeconds; } keyframes.Add(new DiscreteMatrixKeyFrame(new Matrix(endScale, 0, 0, endScale, endPoint.X, endPoint.Y), KeyTime.FromTimeSpan(TimeSpan.FromMilliseconds(0)))); return keyframes; }

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  • MySql multiple selects batching in .net

    - by Amith George
    I have a situation in my application. For each x-axis point in my chart, I am plotting 5 y-axis values. To calculate each of these 5 values, I need to make 4 different queries. Ie, for each x-axis point I need to fire 20 sql queries. Now, I need to plot 40 such points in the my chart. Its resulting in a pathetic performance where it takes close to a minute to get all the data back from the database. Each of 4 different queries consists of a join between 2 tables. One has only 6 rows. The other close to 10,000. Each of the 4 queries has different WHERE clauses, so they are different queries. For each point in the x-axis, only the values for the where clauses change. I have tried combining each of the 4 queries into one big string. Basically batch the four selects. These are again batched for each y-axis value. So, for each x-axis point, I am now firing one big command that consists of 20 different select statements. Technically, I should be experiencing a big performance boost, right? Instead of hitting the db 40x5x4 = 800 times, I am now hitting it just 40 times. But instead of taking 60 seconds, it taking 50-55 seconds... not much of a help. I am using MySql 5.1, and the 6.1 version of its .Net connector. What can I do to improve the performance? Edit: One of the 4 queries is as follows: SELECT SUM(TIME_TO_SEC(TIMEDIFF(T1.col2, T1.col1))* T2.col1 / (3600 *1000)) AS TotalTime FROM Table T1 JOIN Table T2 ON T1.col3 = T2.col3 WHERE T1.col4 = 'i' AND T1.col1 >= '2009-12-25 00:00:00' AND T1.col2 <= '2009-12-26 00:00:00'; The other 3 queries are similar, only the where clause changes slightly. This set of 4 queries is fired 5 times. The first 3 times against the join of table T1 and T2, passing in different values for col4. And the next two times against the join of table T3 and T2 passing in different values for col4. These 5 values are the y-axis values for a particular x-axis point. The data returned by all these queries is the same format. so, we tried doing a UNION ALL on all these queries. No substantial difference. One strange thing, however, after indexing the foreign key on the table T1 [while it contained over a lakh records], the queries were using the index, but they had become slower. At times, the queries would take double the time to return the data.

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