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  • concurrency::extent<N> from amp.h

    - by Daniel Moth
    Overview We saw in a previous post how index<N> represents a point in N-dimensional space and in this post we'll see how to define the N-dimensional space itself. With C++ AMP, an N-dimensional space can be specified with the template class extent<N> where you define the size of each dimension. From a look and feel perspective, you'd expect the programmatic interface of a point type and size type to be similar (even though the concepts are different). Indeed, exactly like index<N>, extent<N> is essentially a coordinate vector of N integers ordered from most- to least- significant, BUT each integer represents the size for that dimension (and hence cannot be negative). So, if you read the description of index, you won't be surprised with the below description of extent<N> There is the rank field returning the value of N you passed as the template parameter. You can construct one extent from another (via the copy constructor or the assignment operator), you can construct it by passing an integer array, or via convenience constructor overloads for 1- 2- and 3- dimension extents. Note that the parameterless constructor creates an extent of the specified rank with all bounds initialized to 0. You can access the components of the extent through the subscript operator (passing it an integer). You can perform some arithmetic operations between extent objects through operator overloading, i.e. ==, !=, +=, -=, +, -. There are operator overloads so that you can perform operations between an extent and an integer: -- (pre- and post- decrement), ++ (pre- and post- increment), %=, *=, /=, +=, –= and, finally, there are additional overloads for plus and minus (+,-) between extent<N> and index<N> objects, returning a new extent object as the result. In addition to the usual suspects, extent offers a contains function that tests if an index is within the bounds of the extent (assuming an origin of zero). It also has a size function that returns the total linear size of this extent<N> in units of elements. Example code extent<2> e(3, 4); _ASSERT(e.rank == 2); _ASSERT(e.size() == 3 * 4); e += 3; e[1] += 6; e = e + index<2>(3,-4); _ASSERT(e == extent<2>(9, 9)); _ASSERT( e.contains(index<2>(8, 8))); _ASSERT(!e.contains(index<2>(8, 9))); grid<N> Our upcoming pre-release bits also have a similar type to extent, grid<N>. The way you create a grid is by passing it an extent, e.g. extent<3> e(4,2,6); grid<3> g(e); I am not going to dive deeper into grid, suffice for now to think of grid<N> simply as an alias for the extent<N> object, that you create when you encounter a function that expects a grid object instead of an extent object. Usage The extent class on its own simply defines the size of the N-dimensional space. We'll see in future posts that when you create containers (arrays) and wrappers (array_views) for your data, it is an extent<N> object that you'll need to use to create those (and use an index<N> object to index into them). We'll also see that it is a grid<N> object that you pass to the new parallel_for_each function that I'll cover in the next post. Comments about this post by Daniel Moth welcome at the original blog.

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  • Pantech Link II, Ubuntu and Virtual XP

    - by user85041
    Okay this is my problem. I have a Pantech Link II, dmesg states: [ 896.072037] usb 2-3: new high-speed USB device number 3 using ehci_hcd [ 896.258562] cdc_acm 2-3:1.0: ttyACM0: USB ACM device [ 896.260039] usbcore: registered new interface driver cdc_acm [ 896.260042] cdc_acm: USB Abstract Control Model driver for USB modems and ISDN adapters Have it installed through wine (pc suite and driver) and it doesn't see it. Virtual XP through VMWare Player sees my device, knows it needs a driver. The removable devices says Curitel Pantech USB Device (Maybe Driver). I have PC Suite installed in XP, I install the driver through the executable.. it says problem with installing hardware, and then it disappears. Ubuntu sees it after restart, but if I start XP with that driver installed, it disappears from both and I get these errors in dmesg: [ 1047.760555] /dev/vmmon[2882]: PTSC: initialized at 3093322000 Hz using TSC, TSCs are synchronized. [ 1048.174033] /dev/vmmon[2882]: Monitor IPI vector: 0 [ 1055.293060] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1055.293074] /dev/vmnet: port on hub 8 successfully opened [ 1055.293088] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1055.293094] /dev/vmnet: port on hub 8 successfully opened [ 1072.446305] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1072.446316] /dev/vmnet: port on hub 8 successfully opened [ 1072.446328] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1072.446334] /dev/vmnet: port on hub 8 successfully opened [ 1072.856024] usb 1-1: reset high-speed USB device number 2 using ehci_hcd [ 1079.292024] usb 1-1: reset high-speed USB device number 2 using ehci_hcd [ 1079.732024] usb 1-1: reset high-speed USB device number 2 using ehci_hcd [ 1127.743034] NET: Registered protocol family 39 [ 1127.749320] [3163]: VMCI: IOCTL_VMCI_QUEUEPAIR_ALLOC (cid=1522210225,result=4). [ 1144.104031] usb 2-3: reset high-speed USB device number 3 using ehci_hcd [ 1144.412031] usb 2-3: reset high-speed USB device number 3 using ehci_hcd [ 1155.889976] ehci_hcd 0000:00:13.2: force halt; handshake ffffc90000642024 00004000 00000000 -> -110 [ 1155.889980] ehci_hcd 0000:00:13.2: HC died; cleaning up [ 1155.890008] usb 2-3: USB disconnect, device number 3 [ 1155.890013] usb 2-3: usbfs: usb_submit_urb returned -110 [ 1658.310777] [3163]: VMCI: IOCTL_VMCI_QUEUEPAIR_DETACH (cid=1522210225,result=3). [ 1658.392018] NET: Unregistered protocol family 39 [ 1666.546438] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1666.546450] /dev/vmnet: port on hub 8 successfully opened [ 1666.546462] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1666.546467] /dev/vmnet: port on hub 8 successfully opened [ 1671.431383] uvcvideo: Found UVC 1.00 device USB2.0 Camera (1871:0101) [ 1671.432533] input: USB2.0 Camera as /devices/pci0000:00/0000:00:12.2/usb1/1-1/1-1:1.0/input/input13 lessa@X:~$ dmesg|tail [ 1155.890008] usb 2-3: USB disconnect, device number 3 [ 1155.890013] usb 2-3: usbfs: usb_submit_urb returned -110 [ 1658.310777] [3163]: VMCI: IOCTL_VMCI_QUEUEPAIR_DETACH (cid=1522210225,result=3). [ 1658.392018] NET: Unregistered protocol family 39 [ 1666.546438] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1666.546450] /dev/vmnet: port on hub 8 successfully opened [ 1666.546462] /dev/vmnet: open called by PID 3163 (vmx-vcpu-0) [ 1666.546467] /dev/vmnet: port on hub 8 successfully opened [ 1671.431383] uvcvideo: Found UVC 1.00 device USB2.0 Camera (1871:0101) [ 1671.432533] input: USB2.0 Camera as /devices/pci0000:00/0000:00:12.2/usb1/1-1/1-1:1.0/input/input13 I have tried uninstalling, and installing manually from the device manager update driver while it's still has the warning sign.. it doesn't see the drivers as valid. No idea how to fix this.. would prefer to not have to go to another computer. I'm not trying to do anything but get the pictures off of it. I have to restart ubuntu, plug in device, for ubuntu to see it correctly again. I am like a month and a half old linux newbie so I have no idea the commands I could use for this, and I don't have a memory card in the phone to mount.

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  • OpenGL Fast-Object Instancing Error

    - by HJ Media Studios
    I have some code that loops through a set of objects and renders instances of those objects. The list of objects that needs to be rendered is stored as a std::map, where an object of class MeshResource contains the vertices and indices with the actual data, and an object of classMeshRenderer defines the point in space the mesh is to be rendered at. My rendering code is as follows: glDisable(GL_BLEND); glEnable(GL_CULL_FACE); glDepthMask(GL_TRUE); glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glEnable(GL_DEPTH_TEST); for (std::map<MeshResource*, std::vector<MeshRenderer*> >::iterator it = renderables.begin(); it != renderables.end(); it++) { it->first->setupBeforeRendering(); cout << "<"; for (unsigned long i =0; i < it->second.size(); i++) { //Pass in an identity matrix to the vertex shader- used here only for debugging purposes; the real code correctly inputs any matrix. uniformizeModelMatrix(Matrix4::IDENTITY); /** * StartHere fix rendering problem. * Ruled out: * Vertex buffers correctly. * Index buffers correctly. * Matrices correct? */ it->first->render(); } it->first->cleanupAfterRendering(); } geometryPassShader->disable(); glDepthMask(GL_FALSE); glDisable(GL_CULL_FACE); glDisable(GL_DEPTH_TEST); The function in MeshResource that handles setting up the uniforms is as follows: void MeshResource::setupBeforeRendering() { glEnableVertexAttribArray(0); glEnableVertexAttribArray(1); glEnableVertexAttribArray(2); glEnableVertexAttribArray(3); glEnableVertexAttribArray(4); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, iboID); glBindBuffer(GL_ARRAY_BUFFER, vboID); glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), 0); // Vertex position glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 12); // Vertex normal glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 24); // UV layer 0 glVertexAttribPointer(3, 3, GL_FLOAT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 32); // Vertex color glVertexAttribPointer(4, 1, GL_UNSIGNED_SHORT, GL_FALSE, sizeof(Vertex), (const GLvoid*) 44); //Material index } The code that renders the object is this: void MeshResource::render() { glDrawElements(GL_TRIANGLES, geometry->numIndices, GL_UNSIGNED_SHORT, 0); } And the code that cleans up is this: void MeshResource::cleanupAfterRendering() { glDisableVertexAttribArray(0); glDisableVertexAttribArray(1); glDisableVertexAttribArray(2); glDisableVertexAttribArray(3); glDisableVertexAttribArray(4); } The end result of this is that I get a black screen, although the end of my rendering pipeline after the rendering code (essentially just drawing axes and lines on the screen) works properly, so I'm fairly sure it's not an issue with the passing of uniforms. If, however, I change the code slightly so that the rendering code calls the setup immediately before rendering, like so: void MeshResource::render() { setupBeforeRendering(); glDrawElements(GL_TRIANGLES, geometry->numIndices, GL_UNSIGNED_SHORT, 0); } The program works as desired. I don't want to have to do this, though, as my aim is to set up vertex, material, etc. data once per object type and then render each instance updating only the transformation information. The uniformizeModelMatrix works as follows: void RenderManager::uniformizeModelMatrix(Matrix4 matrix) { glBindBuffer(GL_UNIFORM_BUFFER, globalMatrixUBOID); glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(Matrix4), matrix.ptr()); glBindBuffer(GL_UNIFORM_BUFFER, 0); }

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  • XNA - 3D AABB collision detection and response

    - by fastinvsqrt
    I've been fiddling around with 3D AABB collision in my voxel engine for the last couple of days, and every method I've come up with thus far has been almost correct, but each one never quite worked exactly the way I hoped it would. Currently what I do is get two bounding boxes for my entity, one modified by the X translation component and the other by the Z component, and check if each collides with any of the surrounding chunks (chunks have their own octrees that are populated only with blocks that support collision). If there is a collision, then I cast out rays into that chunk to get the shortest collision distance, and set the translation component to that distance if the component is greater than the distance. The problem is that sometimes collisions aren't even registered. Here's a video on YouTube that I created showing what I mean. I suspect the problem may be with the rays that I cast to get the collision distance not being where I think they are, but I'm not entirely sure what would be wrong with them if they are indeed the problem. Here is my code for collision detection and response in the X direction (the Z direction is basically the same): // create the XZ offset vector Vector3 offsXZ = new Vector3( ( _translation.X > 0.0f ) ? SizeX / 2.0f : ( _translation.X < 0.0f ) ? -SizeX / 2.0f : 0.0f, 0.0f, ( _translation.Z > 0.0f ) ? SizeZ / 2.0f : ( _translation.Z < 0.0f ) ? -SizeZ / 2.0f : 0.0f ); // X physics BoundingBox boxx = GetBounds( _translation.X, 0.0f, 0.0f ); if ( _translation.X > 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Right, offsXZ ) - 0.0001f; if ( dist < _translation.X ) { _translation.X = dist; } } } } else if ( _translation.X < 0.0f ) { foreach ( Chunk chunk in surrounding ) { if ( chunk.Collides( boxx ) ) { float dist = GetShortestCollisionDistance( chunk, Vector3.Left, offsXZ ) - 0.0001f; if ( dist < -_translation.X ) { _translation.X = -dist; } } } } And here is my implementation for GetShortestCollisionDistance: private float GetShortestCollisionDistance( Chunk chunk, Vector3 rayDir, Vector3 offs ) { int startY = (int)( -SizeY / 2.0f ); int endY = (int)( SizeY / 2.0f ); int incY = (int)Cube.Size; float dist = Chunk.Size; for ( int y = startY; y <= endY; y += incY ) { // Position is the center of the entity's bounding box Ray ray = new Ray( new Vector3( Position.X + offs.X, Position.Y + offs.Y + y, Position.Z + offs.Z ), rayDir ); // Chunk.GetIntersections(Ray) returns Dictionary<Block, float?> foreach ( var pair in chunk.GetIntersections( ray ) ) { if ( pair.Value.HasValue && pair.Value.Value < dist ) { dist = pair.Value.Value; } } } return dist; } I realize some of this code can be consolidated to help with speed, but my main concern right now is to get this bit of physics programming to actually work.

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  • Entity System with C++ templates

    - by tommaisey
    I've been getting interested in the Entity/Component style of game programming, and I've come up with a design in C++ which I'd like a critique of. I decided to go with a fairly pure Entity system, where entities are simply an ID number. Components are stored in a series of vectors - one for each Component type. However, I didn't want to have to add boilerplate code for every new Component type I added to the game. Nor did I want to use macros to do this, which frankly scare me. So I've come up with a system based on templates and type hinting. But there are some potential issues I'd like to check before I spend ages writing this (I'm a slow coder!) All Components derive from a Component base class. This base class has a protected constructor, that takes a string parameter. When you write a new derived Component class, you must initialise the base with the name of your new class in a string. When you first instantiate a new DerivedComponent, it adds the string to a static hashmap inside Component mapped to a unique integer id. When you subsequently instantiate more Components of the same type, no action is taken. The result (I think) should be a static hashmap with the name of each class derived from Component that you instantiate at least once, mapped to a unique id, which can by obtained with the static method Component::getTypeId ("DerivedComponent"). Phew. The next important part is TypedComponentList<typename PropertyType>. This is basically just a wrapper to an std::vector<typename PropertyType> with some useful methods. It also contains a hashmap of entity ID numbers to slots in the array so we can find Components by their entity owner. Crucially TypedComponentList<> is derived from the non-template class ComponentList. This allows me to maintain a list of pointers to ComponentList in my main ComponentManager, which actually point to TypedComponentLists with different template parameters (sneaky). The Component manager has template functions such as: template <typename ComponentType> void addProperty (ComponentType& component, int componentTypeId, int entityId) and: template <typename ComponentType> TypedComponentList<ComponentType>* getComponentList (int componentTypeId) which deal with casting from ComponentList to the correct TypedComponentList for you. So to get a list of a particular type of Component you call: TypedComponentList<MyComponent>* list = componentManager.getComponentList<MyComponent> (Component::getTypeId("MyComponent")); Which I'll admit looks pretty ugly. Bad points of the design: If a user of the code writes a new Component class but supplies the wrong string to the base constructor, the whole system will fail. Each time a new Component is instantiated, we must check a hashed string to see if that component type has bee instantiated before. Will probably generate a lot of assembly because of the extensive use of templates. I don't know how well the compiler will be able to minimise this. You could consider the whole system a bit complex - perhaps premature optimisation? But I want to use this code again and again, so I want it to be performant. Good points of the design: Components are stored in typed vectors but they can also be found by using their entity owner id as a hash. This means we can iterate them fast, and minimise cache misses, but also skip straight to the component we need if necessary. We can freely add Components of different types to the system without having to add and manage new Component vectors by hand. What do you think? Do the good points outweigh the bad?

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  • glm matrix conversion for DirectX

    - by niktehpui
    For on of the coursework specification I need to work with DirectX, so I tried to implement a DirectX Renderer in my small cross-platform framework (to have it optionally available for Windows). Since I want to stick to my dependencies I want use glm for vector/matrix/quaternions math. The vectors seem to be fully compatible with DirectX, but the glm::mat4 is not working properly in DirectX Effects Framework. I assumed the reason is that DirectX uses row majors layouts and OpenGL column majors (although if I remember right internally in HLSL DX uses column major as well), so I transposed the matrix, but I still get no proper results compared to using XNA-Math. XNA-Version of the code (works): XMMATRIX world = XMMatrixIdentity(); XMMATRIX view = XMMatrixLookAtLH(XMVectorSet(5.0, 5.0, 5.0, 1.0f), XMVectorZero(), XMVectorSet(0.0f, 1.0f, 0.0f, 0.0f)); XMMATRIX proj = XMMatrixPerspectiveFovLH(0.25f*3.14f, 1.25f, 1.0f, 1000.0f); XMMATRIX worldViewProj = world*view*proj; m_fxWorldViewProj->SetMatrix(reinterpret_cast<float*>(&worldViewProj)); This works flawlessly and displays the expected colored cube. GLM-Version (does not work): glm::mat4 world(1.0f); glm::mat4 view = glm::lookAt(glm::vec3(5.0f, 5.0f, 5.0f), glm::vec3(0.0f, 0.0f, 0.0f), glm::vec3(0.0f, 1.0f, 0.0f)); glm::mat4 proj = glm::perspective(0.25f*3.14f, 1.25f, 1.0f, 1000.0f); glm::mat4 worldViewProj = glm::transpose(world*view*proj); m_fxWorldViewProj->SetMatrix(glm::value_ptr(worldViewProj)); Displays nothing, screen stays black. I really would like to stick to glm on all platforms.

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  • VS2008 -> VS2010 leads to cryptic STL errors

    - by Jakobud
    The following C++ library was successfully compiled in VS2008 http://sourceforge.net/projects/xmlrpcc4win/files/xmlrpcc4win/XmlRpcC4Win1.0.8.zip/download When I open it in VS2010, it goes through the conversion wizard process without any errors. Now, when I attempt to compile it in VS2010, I get some weird STL errors like these: 1>TimXmlRpc.cpp(1018): error C2039: 'back_insert_iterator' : is not a member of 'std' 1>TimXmlRpc.cpp(1018): error C2065: 'back_insert_iterator' : undeclared identifier 1>TimXmlRpc.cpp(1018): error C2275: 'XmlRpcValue::BinaryData' : illegal use of this type as an expression 1>TimXmlRpc.cpp(1018): error C2065: 'ins' : undeclared identifier 1>TimXmlRpc.cpp(1018): error C2039: 'back_inserter' : is not a member of 'std' 1>TimXmlRpc.cpp(1018): error C3861: 'back_inserter': identifier not found 1>TimXmlRpc.cpp(1019): error C2065: 'ins' : undeclared identifier 1>TimXmlRpc.cpp(1031): error C2039: 'back_insert_iterator' : is not a member of 'std' 1>TimXmlRpc.cpp(1031): error C2065: 'back_insert_iterator' : undeclared identifier 1>TimXmlRpc.cpp(1031): error C2275: 'std::vector<_Ty>' : illegal use of this type as an expression 1> with 1> [ 1> _Ty=char 1> ] 1>TimXmlRpc.cpp(1031): error C2065: 'ins' : undeclared identifier 1>TimXmlRpc.cpp(1031): error C2039: 'back_inserter' : is not a member of 'std' 1>TimXmlRpc.cpp(1031): error C3861: 'back_inserter': identifier not found 1>TimXmlRpc.cpp(1032): error C2065: 'ins' : undeclared identifier I'm not sure what to make of some of these. For instance, back_insert_iterator is in fact a member of std, but VS doesn't seem to think it is. How do I fix errors like these? They just don't seem to make much sense so I'm not sure where to begin. Perhaps its something in my project settings? For example, here is line 1018, which gives the std error: std::back_insert_iterator<BinaryData> ins = std::back_inserter(*(u.asBinary)); If anyone could give me some direction I'd appreciate it. I'm new enough to C++ that I'm having a tough time figuring out this one.

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  • Using the Rijndael Object in VB.NET

    - by broke
    I'm trying out the Rijndael to generate an encrypted license string to use for our new software, so we know that our customers are using the same amount of apps that they paid for. I'm doing two things: Getting the users computer name. Adding a random number between 100 and 1000000000 I then combine the two, and use that as the license number(This probably will change in the final version, but I'm just doing something simple for demonstration purposes). Here is some sample codez: Private Sub Main_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim generator As New Random Dim randomValue As Integer randomValue = generator.Next(100, 1000000000) ' Create a new Rijndael object to generate a key ' and initialization vector (IV). Dim RijndaelAlg As Rijndael = Rijndael.Create ' Create a string to encrypt. Dim sData As String = My.Computer.Name.ToString + randomValue.ToString Dim FileName As String = "C:\key.txt" ' Encrypt text to a file using the file name, key, and IV. EncryptTextToFile(sData, FileName, RijndaelAlg.Key, RijndaelAlg.IV) ' Decrypt the text from a file using the file name, key, and IV. Dim Final As String = DecryptTextFromFile(FileName, RijndaelAlg.Key, RijndaelAlg.IV) txtDecrypted.Text = Final End Sub That's my load event, but here is where the magic happens: Sub EncryptTextToFile(ByVal Data As String, ByVal FileName As String, ByVal Key() As Byte, ByVal IV() As Byte) Dim fStream As FileStream = File.Open(FileName, FileMode.OpenOrCreate) Dim RijndaelAlg As Rijndael = Rijndael.Create Dim cStream As New CryptoStream(fStream, _ RijndaelAlg.CreateEncryptor(Key, IV), _ CryptoStreamMode.Write) Dim sWriter As New StreamWriter(cStream) sWriter.WriteLine(Data) sWriter.Close() cStream.Close() fStream.Close() End Sub There is a couple things I don't understand. What if someone reads the text file and recognizes that it is Rijndael, and writes a VB or C# app that decrypts it? I don't really understand all of this code, so if you guys can help me out I will love you all forever. Thanks in advance

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  • Sample uniformly at random from an n-dimensional unit simplex.

    - by dreeves
    Sampling uniformly at random from an n-dimensional unit simplex is the fancy way to say that you want n random numbers such that they are all non-negative, they sum to one, and every possible vector of n non-negative numbers that sum to one are equally likely. In the n=2 case you want to sample uniformly from the segment of the line x+y=1 (ie, y=1-x) that is in the positive quadrant. In the n=3 case you're sampling from the triangle-shaped part of the plane x+y+z=1 that is in the positive octant of R3: (Image from http://en.wikipedia.org/wiki/Simplex.) Note that picking n uniform random numbers and then normalizing them so they sum to one does not work. You end up with a bias towards less extreme numbers. Similarly, picking n-1 uniform random numbers and then taking the nth to be one minus the sum of them also introduces bias. Wikipedia gives two algorithms to do this correctly: http://en.wikipedia.org/wiki/Simplex#Random_sampling (Though the second one currently claims to only be correct in practice, not in theory. I'm hoping to clean that up or clarify it when I understand this better. I initially stuck in a "WARNING: such-and-such paper claims the following is wrong" on that Wikipedia page and someone else turned it into the "works only in practice" caveat.) Finally, the question: What do you consider the best implementation of simplex sampling in Mathematica (preferably with empirical confirmation that it's correct)? Related questions http://stackoverflow.com/questions/2171074/generating-a-probability-distribution http://stackoverflow.com/questions/3007975/java-random-percentages

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  • Need help with artificial neural network

    - by deckard cain
    I have an input data for neural network that consists of 2 vectors with 200 elements, that i got from some program for generating signals. So it is actually 2x200 input to my nnet. As target data, i have one 1x200 vector that i also got from the same program. That is my training data set. I gather as much of those sets as i want so i transfer them to matlab and save them as, for example, set1, set2,.... When i am creating neural net, using newfit function (backropagation algorithm and everyhting else is set by default because i am kind of unexperianced with neural nets so i will have to experiment) i'm creating it using set1 only for example. Then, when i am to train neural net i train it for set1 then load set2 and train for it and so on. so its like this function net = create_fit_net(inputs,targets) numHiddenNeurons = 20; net = newfit(inputs,targets,numHiddenNeurons); net=train(net,inputs,targets); load set2; net=train(net,inputs,targets); load set3; net=train(net,inputs,targets); load set4; net=train(net,inputs,targets); i am using 4 sets of data here and all sets have variables of same name and size. My quesion is, am i doing this the right way, because, when doing simulation in some other m file, i am getting bad results, and every time i get different results. Does it matter if i create network with one set and then train with others too, and does it matter what set do i use to train network 1st? Also, i am confused about the amount of neurons to use (im using in the example 20 but actually i tried 1, 10, 30, 50, 100 200 and even 300 and i get nothing). If you have any suggestions, i'd be glad to take them into consideration. Any help is welcome. thanks in advance

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  • Android Client : Web service - what's the correct SOAP_ACTION, METHOD_NAME, NAMESPACE, URL I should

    - by Hubert
    if I want to use the following Web service (help.be is just an example, let's say it does exist): http://www.help.be/webservice/webservice_help.php (it's written in PHP=client's choice, not .NET) with the following WSDL : <?xml version="1.0" encoding="UTF-8"?> <definitions xmlns="http://schemas.xmlsoap.org/wsdl/" name="webservice_help" targetNamespace="http://www.help.be/webservice/webservice_help.php" xmlns:tns="http://www.help.be/webservice/webservice_help.php" xmlns:impl="http://www.help.be/webservice/webservice_help.php" xmlns:xsd1="http://www.help.be/webservice/webservice_help.php" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:soapenc="http://schemas.xmlsoap.org/soap/encoding/"> <portType name="webservice_helpPortType"> <operation name="webservice_help"> <input message="tns:Webservice_helpRequest"/> </operation> <operation name="getLocation" parameterOrder="input"> <input message="tns:GetLocationRequest"/> <output message="tns:GetLocationResponse"/> </operation> <operation name="getStationDetail" parameterOrder="input"> <input message="tns:GetStationDetailRequest"/> <output message="tns:GetStationDetailResponse"/> </operation> <operation name="getStationList" parameterOrder="input"> <input message="tns:GetStationListRequest"/> <output message="tns:GetStationListResponse"/> </operation> </portType> <binding name="webservice_helpBinding" type="tns:webservice_helpPortType"> <soap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http"/> <operation name="webservice_help"> <soap:operation soapAction="urn:webservice_help#webservice_helpServer#webservice_help"/> <input> <soap:body use="encoded" namespace="http://www.help.be/webservice/webservice_help.php" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> </input> </operation> <operation name="getLocation"> <soap:operation soapAction="urn:webservice_help#webservice_helpServer#getLocation"/> <input> <soap:body parts="input" use="encoded" namespace="http://www.help.be/webservice/webservice_help.php" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> </input> <output> <soap:body parts="return" use="encoded" namespace="http://www.help.be/webservice/webservice_help.php" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> </output> </operation> <operation name="getStationDetail"> <soap:operation soapAction="urn:webservice_help#webservice_helpServer#getStationDetail"/> <input> <soap:body parts="input" use="encoded" namespace="http://www.help.be/webservice/webservice_help.php" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> </input> <output> <soap:body parts="return" use="encoded" namespace="http://www.help.be/webservice/webservice_help.php" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> </output> </operation> <operation name="getStationList"> <soap:operation soapAction="urn:webservice_help#webservice_helpServer#getStationList"/> <input> <soap:body parts="input" use="encoded" namespace="http://www.help.be/webservice/webservice_help.php" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> </input> <output> <soap:body parts="return" use="encoded" namespace="http://www.help.be/webservice/webservice_help.php" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/> </output> </operation> </binding> <message name="Webservice_helpRequest"/> <message name="GetLocationRequest"> <part name="input" type="xsd:array"/> </message> <message name="GetLocationResponse"> <part name="return" type="xsd:array"/> </message> <message name="GetStationDetailRequest"> <part name="input" type="xsd:array"/> </message> <message name="GetStationDetailResponse"> <part name="return" type="xsd:string"/> </message> <message name="GetStationListRequest"> <part name="input" type="xsd:array"/> </message> <message name="GetStationListResponse"> <part name="return" type="xsd:string"/> </message> <service name="webservice_helpService"> <port name="webservice_helpPort" binding="tns:webservice_helpBinding"> <soap:address location="http://www.help.be/webservice/webservice_help.php"/> </port> </service> </definitions> What is the correct SOAP_ACTION, METHOD_NAME, NAMESPACE, URL I should use below ? I've tried with this : public class Main extends Activity { /** Called when the activity is first created. */ private static final String SOAP_ACTION_GETLOCATION = "getLocation"; private static final String METHOD_NAME_GETLOCATION = "getLocation"; private static final String NAMESPACE = "http://www.help.be/webservice/"; private static final String URL = "http://www.help.be/webservice/webservice_help.php"; TextView tv; @SuppressWarnings("unchecked") @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); tv = (TextView)findViewById(R.id.TextView01); // -------------------------------------------------------------------------------------- SoapObject request_location = new SoapObject(NAMESPACE, METHOD_NAME_GETLOCATION); request_location.addProperty("login", "login"); // -> string required request_location.addProperty("password", "password"); // -> string required request_location.addProperty("serial", "serial"); // -> string required request_location.addProperty("language", "fr"); // -> string required (available « fr,nl,uk,de ») request_location.addProperty("keyword", "Braine"); // -> string required // -------------------------------------------------------------------------------------- SoapSerializationEnvelope soapEnvelope = new SoapSerializationEnvelope(SoapEnvelope.VER11); //soapEnvelope.dotNet = true; // don't forget it for .NET WebServices ! soapEnvelope.setOutputSoapObject(request_location); AndroidHttpTransport aht = new AndroidHttpTransport(URL); try { aht.call(SOAP_ACTION_GETLOCATION, soapEnvelope); // Get the SAOP Envelope back and then extract the body SoapObject resultsRequestSOAP = (SoapObject) soapEnvelope.bodyIn; Vector XXXX = (Vector) resultsRequestSOAP.getProperty("GetLocationResponse"); int vector_size = XXXX.size(); Log.i("Hub", "testat="+vector_size); tv.setText("OK"); } catch(Exception E) { tv.setText("ERROR:" + E.getClass().getName() + ": " + E.getMessage()); Log.i("Hub", "Exception E"); Log.i("Hub", "E.getClass().getName()="+E.getClass().getName()); Log.i("Hub", "E.getMessage()="+E.getMessage()); } // -------------------------------------------------------------------------------------- } } I'm not sure of the SOAP_ACTION, METHOD_NAME, NAMESPACE, URL I have to use? because soapAction is pointing to a URN instead of a traditional URL and it's PHP and not .NET ... also, I'm not sure if I have to use request_location.addProperty("login", "login"); of request_location.addAttribute("login", "login"); ? = <message name="GetLocationRequest"> <part name="input" type="xsd:array"/> What would you say ? Txs for your help. H. EDIT : Here is some code working in PHP - I simply want to have the same but in Android/JAVA : <?php ini_set("soap.wsdl_cache_enabled", "0"); // disabling WSDL cache $request['login'] = 'login'; $request['password'] = 'password'; $request['serial'] = 'serial'; $request['language'] = 'fr'; $client= new SoapClient("http://www.test.be/webservice/webservice_test.wsdl"); print_r( $client->__getFunctions()); ?><hr><h1>getLocation</h1> <h2>Input:</h2> <? $request['keyword'] = 'Bruxelles'; print_r($request); ?><h2>Result</h2><? $result = $client->getLocation($request); print_r($result); ?>

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  • Scaling a CBitmap - what am I doing wrong?

    - by Smashery
    I've written the following code, which attempts to take a 32x32 bitmap (loaded through MFC's Resource system) and turn it into a 16x16 bitmap, so they can be used as the big and small CImageLists for a CListCtrl. However, when I open the CListCtrl, all the icons are black (in both small and large view). Before I started playing with resizing, everything worked perfectly in Large View. What am I doing wrong? // Create the CImageLists if (!m_imageListL.Create(32,32,ILC_COLOR24, 1, 1)) { throw std::exception("Failed to create CImageList"); } if (!m_imageListS.Create(16,16,ILC_COLOR24, 1, 1)) { throw std::exception("Failed to create CImageList"); } // Fill the CImageLists with items loaded from ResourceIDs int i = 0; for (std::vector<UINT>::iterator it = vec.begin(); it != vec.end(); it++, i++) { CBitmap* bmpBig = new CBitmap(); bmpBig->LoadBitmap(*it); CDC bigDC; bigDC.CreateCompatibleDC(m_itemList.GetDC()); bigDC.SelectObject(bmpBig); CBitmap* bmpSmall = new CBitmap(); bmpSmall->CreateBitmap(16, 16, 1, 24, 0); CDC smallDC; smallDC.CreateCompatibleDC(&bigDC); smallDC.SelectObject(bmpSmall); smallDC.StretchBlt(0, 0, 32, 32, &bigDC, 0, 0, 16, 16, SRCCOPY); m_imageListL.Add(bmpBig, RGB(0,0,0)); m_imageListS.Add(bmpSmall, RGB(0,0,0)); } m_itemList.SetImageList(&m_imageListS, LVSIL_SMALL); m_itemList.SetImageList(&m_imageListL, LVSIL_NORMAL);

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  • Open source GIS tools

    - by TRV_SQL
    Hi I’ve been looking at Open Source GIS tools. In particular MapServer and GeoServer. The problem I’m seeing is that to actually deploy these to the public you can’t use a regular $5/ month (or free) hosting service because you have to install these services on the server in ways that are not accessible in the average hosting scheme. So you either have to use a host that has MapServer installed (many of which look unreliable) or have a dedicated server or VPS. All of these options have a significant cost barrier ($30 - $200/month). I’m just doing this for fun. Are there any free or inexpensive ways to have your GIS services hosted? Or are there any products that install in a way that you don’t need to access the root structure of the server? I have tried OpenLayers and GeoExt but I don’t think a client side option will work for me because of the size of the datasets I am using. My base data will be vector data not WMS data (or something similar). I haven’t tried Google maps yet, but I will be looking into it. Also, any thought on using SVG for GIS purposes? Thanks

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  • Disco/MapReduce: Using results of previous iteration as input to new iteration

    - by muckabout
    Currently am implementing PageRank on Disco. As an iterative algorithm, the results of one iteration are used as input to the next iteration. I have a large file which represents all the links, with each row representing a page and the values in the row representing the pages to which it links. For Disco, I break this file into N chunks, then run MapReduce for one round. As a result, I get a set of (page, rank) tuples. I'd like to feed this rank to the next iteration. However, now my mapper needs two inputs: the graph file, and the pageranks. I would like to "zip" together the graph file and the page ranks, such that each line represents a page, it's rank, and it's out links. Since this graph file is separated into N chunks, I need to split the pagerank vector into N parallel chunks, and zip the regions of the pagerank vectors to the graph chunks This all seems more complicated than necessary, and as a pretty straightforward operation (with the quintessential mapreduce algorithm), it seems I'm missing something about Disco that could really simplify the approach. Any thoughts?

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  • Calculating skew of text OpenCV

    - by Nick
    I am trying to calculate the skew of text in an image so I can correct it for the best OCR results. Currently this is the function I am using: double compute_skew(Mat &img) { // Binarize cv::threshold(img, img, 225, 255, cv::THRESH_BINARY); // Invert colors cv::bitwise_not(img, img); cv::Mat element = cv::getStructuringElement(cv::MORPH_RECT, cv::Size(5, 3)); cv::erode(img, img, element); std::vector<cv::Point> points; cv::Mat_<uchar>::iterator it = img.begin<uchar>(); cv::Mat_<uchar>::iterator end = img.end<uchar>(); for (; it != end; ++it) if (*it) points.push_back(it.pos()); cv::RotatedRect box = cv::minAreaRect(cv::Mat(points)); double angle = box.angle; if (angle < -45.) angle += 90.; cv::Point2f vertices[4]; box.points(vertices); for(int i = 0; i < 4; ++i) cv::line(img, vertices[i], vertices[(i + 1) % 4], cv::Scalar(255, 0, 0), 1, CV_AA); return angle; } When I look at then angle in debug I get 0.000000 However when I give it this image I get proper results of a skew of about 16 degrees: How can I properly detect the skew in the first image?

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  • Advice using leaks in instruments for noobs

    - by Gyozo Kudor
    Hello I am pretty new to iphone development. I have run my app for the first time using the "Leaks" from "Instruments". It shows me several leaks around 20 the smallest is 32 bytes and there is one with 1KB. I have followed the memory management guidelines, (i (think i) understand how and when to use release, not to use it when adding to autorelease pools, for every copy, retain, init there should be a release,... etc). I don't think I understand the output of the Leaks in instruments. What does "Responsible library" and "Responsible frame" mean. Because there are some classes and methods i never used directly. Are there any good tutorials for debugging memory leaks in instruments or other advice you can give me regarding leaks. Thanks in advance. Here are the largest 2 leaks. Leaked Object # Address Size Responsible Library Responsible Frame Malloc 1.00 KB 0x4827400 1024 CFNetwork std::vector *, std::allocator * ::reserve(unsigned long) // i have no idea what this is. Leaked Object # Address Size Responsible Library Responsible Frame Malloc 128 Bytes 5 640 UIKit UIImagePickerLoadPhotoLibraryIfNecessary // so this means UIImagePicker is leaking memory? The first leak i get Leaked Object # Address Size Responsible Library Responsible Frame Malloc 128 Bytes 0x442dfd0 128 UIKit UIKeyboardInputManagerClassForInputMode I don't understand any of those.

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  • Typedef and Struct in C and H files

    - by Leif Andersen
    I've been using the following code to create various struct, but only give people outside of the C file a pointer to it. (Yes, I know that they could potentially mess around with it, so it's not entirely like the private keyword in Java, but that's okay with me). Anyway, I've been using the following code, and I looked at it today, and I'm really surprised that it's actually working, can anyone explain why this is? In my C file, I create my struct, but don't give it a tag in the typedef namespace: struct LABall { int x; int y; int radius; Vector velocity; }; And in the H file, I put this: typedef struct LABall* LABall; I am obviously using #import "LABall.h" in the c file, but I am NOT using #import "LABall.c" in the header file, as that would defeat the whole purpose of a separate header file. So, why am I able to create a pointer to the LABall* struct in the H file when I haven't actually included it? Does it have something to do with the struct namespace working accross files, even when one file is in no way linked to another? Thank you.

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  • Spatial Rotation in Gmod Expression2.

    - by Fascia
    I'm using expression2 to program behavior in Garry's mod (http://wiki.garrysmod.com/?title=Wire_Expression2) Okay so, to set the precedent. In Gmod I have a block and I am at a complete loss of how to get it to rotate around the 3 up, down and right vectors (Which are local. ie; if I pitch it 45 degrees the forward vector is 0.707, 0.707, 0). Essentially, From the 3 vectors I'd like to be able to get local Pitch/Roll/Yaw. By Local Pitch Roll Yaw I mean that they are completely independent of one another allowing true 3d rotation. So for example; if I place my craft so its nose is parallel to the floor the X,Y,Z would be 0,0,0. If I turn it parallel to the floor (World and Local Yaw) 90 degrees it's now 0, 0, 90. If I then pitch it (World Roll, Local Pitch) it 180 degrees it's now 180, 0, 90. I've already explored quaternions however I don't believe I should post my code here as I think I was re-inventing the wheel. I know I didn't explain that well but I believe the problem is pretty generic. Any help anyone could offer is greatly appreciated. Oh, I'd like to avoid gimblelock too. Essentially calculating the rotation around each of the crafts up/forward/right vectors using the up/forward/right vectors. To simply the question a generic implementation rather than one specific to Gmod is absolutely fine.

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  • Subset a data.frame by list and apply function on each part, by rows

    - by aL3xa
    This may seem as a typical plyr problem, but I have something different in mind. Here's the function that I want to optimize (skip the for loop). # dummy data set.seed(1985) lst <- list(a=1:10, b=11:15, c=16:20) m <- matrix(round(runif(200, 1, 7)), 10) m <- as.data.frame(m) dfsub <- function(dt, lst, fun) { # check whether dt is `data.frame` stopifnot (is.data.frame(dt)) # check if vectors in lst are "whole" / integer # vector elements should be column indexes is.wholenumber <- function(x, tol = .Machine$double.eps^0.5) abs(x - round(x)) < tol # fall if any non-integers in list idx <- rapply(lst, is.wholenumber) stopifnot(idx) # check for list length stopifnot(ncol(dt) == length(idx)) # subset the data subs <- list() for (i in 1:length(lst)) { # apply function on each part, by row subs[[i]] <- apply(dt[ , lst[[i]]], 1, fun) } # preserve names names(subs) <- names(lst) # convert to data.frame subs <- as.data.frame(subs) # guess what =) return(subs) } And now a short demonstration... actually, I'm about to explain what I primarily intended to do. I wanted to subset a data.frame by vectors gathered in list object. Since this is a part of code from a function that accompanies data manipulation in psychological research, you can consider m as a results from personality questionnaire (10 subjects, 20 vars). Vectors in list hold column indexes that define questionnaire subscales (e.g. personality traits). Each subscale is defined by several items (columns in data.frame). If we presuppose that the score on each subscale is nothing more than sum (or some other function) of row values (results on that part of questionnaire for each subject), you could run: > dfsub(m, lst, sum) a b c 1 46 20 24 2 41 24 21 3 41 13 12 4 37 14 18 5 57 18 25 6 27 18 18 7 28 17 20 8 31 18 23 9 38 14 15 10 41 14 22 I took a glance at this function and I must admit that this little loop isn't spoiling the code at all... BUT, if there's an easier/efficient way of doing this, please, let me know!

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  • Drawing a PDF Right-Side-Up in CGContext

    - by Carter Allen
    I'm overriding the drawRect: method in a custom UIView, and I'm doing some custom drawing. All was going well, until I needed to draw a PDF resource (a vector glyph, to be precise) into the context. First I retrieve the PDF from a file: NSURL *pdfURL = [NSURL fileURLWithPath:[[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"CardKit.bundle/A.pdf"]]; CGPDFDocumentRef pdfDoc = CGPDFDocumentCreateWithURL((CFURLRef)pdfURL); CGPDFPageRef pdfPage = CGPDFDocumentGetPage(pdfDoc, 1); Then I create a box with the same dimensions as the loaded PDF: CGRect box = CGPDFPageGetBoxRect(pdfPage, kCGPDFArtBox); Then I save my graphics state, so that I don't screw anything up: CGContextSaveGState(context); And then I perform a scale+translate of the CTM, theoretically flipping the whole context: CGContextScaleCTM(context, 1.0, -1.0); CGContextTranslateCTM(context, 0.0, rect.size.height); I then scale the PDF so that it fits into the view properly: CGContextScaleCTM(context, rect.size.width/box.size.width, rect.size.height/box.size.height); And finally, I draw the PDF and restore the graphics state: CGContextDrawPDFPage(context, pdfPage); CGContextRestoreGState(context); The issue is that there is nothing visible drawn. All this code should theoretically draw the PDF glyph into the view, right? If I remove the scale+translate used to flip the context, it draws perfectly: it just draws upside-down. Any ideas?

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  • Qt Object Linker Problem " undefined reverence to vtable"

    - by Thomas
    This is my header: #ifndef BARELYSOCKET_H #define BARELYSOCKET_H #include <QObject> //! The First Draw of the BarelySocket! class BarelySocket: public QObject { Q_OBJECT public: BarelySocket(); public slots: void sendMessage(Message aMessage); signals: void reciveMessage(Message aMessage); private: // QVector<Message> reciveMessages; }; #endif // BARELYSOCKET_H This is my class: #include <QTGui> #include <QObject> #include "type.h" #include "client.h" #include "server.h" #include "barelysocket.h" BarelySocket::BarelySocket() { //this->reciveMessages.clear(); qDebug("BarelySocket::BarelySocket()"); } void BarelySocket::sendMessage(Message aMessage) { } void BarelySocket::reciveMessage(Message aMessage) { } I get the Linker Problem : undefined reference to 'vtable for barelySocket' This should mean, i have a virtual Function not implemented. But as you can see, there is non. I comment the vector cause that should solve the Problem, but i does not. The Message is a complex struct, but even converting it to int did not solve it. I searched Mr G but he could not help me. Thank you for your support, Thomas

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  • Fitting Gaussian KDE in numpy/scipy in Python

    - by user248237
    I am fitting a Gaussian kernel density estimator to a variable that is the difference of two vectors, called "diff", as follows: gaussian_kde_covfact(diff, smoothing_param) -- where gaussian_kde_covfact is defined as: class gaussian_kde_covfact(stats.gaussian_kde): def __init__(self, dataset, covfact = 'scotts'): self.covfact = covfact scipy.stats.gaussian_kde.__init__(self, dataset) def _compute_covariance_(self): '''not used''' self.inv_cov = np.linalg.inv(self.covariance) self._norm_factor = sqrt(np.linalg.det(2*np.pi*self.covariance)) * self.n def covariance_factor(self): if self.covfact in ['sc', 'scotts']: return self.scotts_factor() if self.covfact in ['si', 'silverman']: return self.silverman_factor() elif self.covfact: return float(self.covfact) else: raise ValueError, \ 'covariance factor has to be scotts, silverman or a number' def reset_covfact(self, covfact): self.covfact = covfact self.covariance_factor() self._compute_covariance() This works, but there is an edge case where the diff is a vector of all 0s. In that case, I get the error: File "/srv/pkg/python/python-packages/python26/scipy/scipy-0.7.1/lib/python2.6/site-packages/scipy/stats/kde.py", line 334, in _compute_covariance self.inv_cov = linalg.inv(self.covariance) File "/srv/pkg/python/python-packages/python26/scipy/scipy-0.7.1/lib/python2.6/site-packages/scipy/linalg/basic.py", line 382, in inv if info>0: raise LinAlgError, "singular matrix" numpy.linalg.linalg.LinAlgError: singular matrix What's a way to get around this? In this case, I'd like it to return a density that's essentially peaked completely at a difference of 0, with no mass everywhere else. thanks.

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  • How bad is code using std::basic_string<t> as a contiguous buffer?

    - by BillyONeal
    I know technically the std::basic_string template is not required to have contiguous memory. However, I'm curious how many implementations exist for modern compilers that actually take advantage of this freedom. For example, if one wants code like the following it seems silly to allocate a vector just to turn around instantly and return it as a string: DWORD valueLength = 0; DWORD type; LONG errorCheck = RegQueryValueExW( hWin32, value.c_str(), NULL, &type, NULL, &valueLength); if (errorCheck != ERROR_SUCCESS) WindowsApiException::Throw(errorCheck); else if (valueLength == 0) return std::wstring(); std::wstring buffer; do { buffer.resize(valueLength/sizeof(wchar_t)); errorCheck = RegQueryValueExW( hWin32, value.c_str(), NULL, &type, &buffer[0], &valueLength); } while (errorCheck == ERROR_MORE_DATA); if (errorCheck != ERROR_SUCCESS) WindowsApiException::Throw(errorCheck); return buffer; I know code like this might slightly reduce portability because it implies that std::wstring is contiguous -- but I'm wondering just how unportable that makes this code. Put another way, how may compilers actually take advantage of the freedom having noncontiguous memory allows? Oh: And of course given what the code's doing this only matters for Windows compilers.

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  • Trying to parse OpenCV YAML ouput with yaml-cpp

    - by Kenn Sebesta
    I've got a series of OpenCv generated YAML files and would like to parse them with yaml-cpp I'm doing okay on simple stuff, but the matrix representation is proving difficult. # Center of table tableCenter: !!opencv-matrix rows: 1 cols: 2 dt: f data: [ 240, 240] This should map into the vector 240 240 with type float. My code looks like: #include "yaml.h" #include <fstream> #include <string> struct Matrix { int x; }; void operator >> (const YAML::Node& node, Matrix& matrix) { unsigned rows; node["rows"] >> rows; } int main() { std::ifstream fin("monsters.yaml"); YAML::Parser parser(fin); YAML::Node doc; Matrix m; doc["tableCenter"] >> m; return 0; } But I get terminate called after throwing an instance of 'YAML::BadDereference' what(): yaml-cpp: error at line 0, column 0: bad dereference Abort trap I searched around for some documentation for yaml-cpp, but there doesn't seem to be any, aside from a short introductory example on parsing and emitting. Unfortunately, neither of these two help in this particular circumstance. As I understand, the !! indicate that this is a user-defined type, but I don't see with yaml-cpp how to parse that.

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  • Trouble move-capturing std::unique_ptr in a lambda using std::bind

    - by user2478832
    I'd like to capture a variable of type std::vector<std::unique_ptr<MyClass>> in a lambda expression (in other words, "capture by move"). I found a solution which uses std::bind to capture unique_ptr (http://stackoverflow.com/a/12744730/2478832) and decided to use it as a starting point. However, the most simplified version of the proposed code I could get doesn't compile (lots of template mistakes, it seems to try to call unique_ptr's copy constructor). #include <functional> #include <memory> std::function<void ()> a(std::unique_ptr<int>&& param) { return std::bind( [] (int* p) {}, std::move(param)); } int main() { a(std::unique_ptr<int>(new int())); } Can anybody point out what is wrong with this code? EDIT: tried changing the lambda to take a reference to unique_ptr, it still doesn't compile. #include <functional> #include <memory> std::function<void ()> a(std::unique_ptr<int>&& param) { return std::bind( [] (std::unique_ptr<int>& p) {}, // also as a const reference std::move(param)); } int main() { a(std::unique_ptr<int>(new int())); }

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