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  • C++ Expose Already Existing Instance of Objects to a Scripting Language

    - by user947871
    So, I want to be able to modify already instanced C++ objects in a scripting language. I have been looking at Lua with LuaBind and Python with SWIG or Boost::Python, but all I see is how to make new instances of the objects, but I want to modify already existing ones. Example: C++: Player playerOne = new Player(); Scripting Language : playerOne.Transform.x += 5; Is this possible, and if so, wat would you suggest as a good Language/library to achieve this with?

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  • Correct approach to validate attributes of an instance of class

    - by systempuntoout
    Having a simple Python class like this: class Spam(object): __init__(self, description, value): self.description = description self.value = value Which is the correct approach to check these constraints: "description cannot be empty" "value must be greater than zero" Should i: 1.validate data before creating spam object ? 2.check data on __init__ method ? 3.create an is_valid method on Spam class and call it with spam.isValid() ? 4.create an is_valid static method on Spam class and call it with Spam.isValid(description, value) ? 5.check data on setters declaration ? 6.... Could you recommend a well designed\Pythonic\not verbose (on class with many attributes)\elegant approach?

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  • Java ME Runnable object takes up memory although not made an instance yet

    - by user1646684
    I am facing a strange problem with memory in Java ME. here is a part of my code: int variable=1; while (true) { if (variable==2) { display = Display.getDisplay(this); MyCanvas mc = new MyCanvas(this); // MyCanvas is a runnable object mcT = new Thread(mc); // new thread for MyCanvas mc.repaint(); display.setCurrent(mc); mcT.start(); // run thread } if (variable==1) { // Do some other stuff } } The problem is that although still the variable is set to 1, so it does not come through the if (variable==2) condition the program consumes 300kB more memory than when I delete the code after condition if (variable==2). As far as I know the code should by executed and the objects shall be created only when I set variable to value 2. But it consumes the memory also when the code after condition "if (variable==2)" is not executed. Why does this happen?

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  • Testing instance variables from controllers with rspec

    - by Thiago
    Hi, I am trying to get the following spec to run: describe BlacklistController, "GET index" do it "should display the list of universally blocked numbers" do get :index debugger assigns[:blocked_numbers].should contain "190" end end Here's the action def index @blocked_numbers << "190" respond_to do |format| format.html end end And the failure simply says that assigns[:blocked_numbers} is nil. Why's that?

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  • Use reflection to get the value of a property by name in a class instance

    - by TheMoot
    Lets say I have class Person { public Person(int age, string name) { Age = age; Name = name; } public int Age{get;set} public string Name{get;set} } and I would like to create a method that accepts a string that contains either "age" or "name" and returns an object with the value of that property. Like the following pseudo code: public object GetVal(string propName) { return <propName>.value; } How can I do this using reflection? I am coding using asp.net 3.5, c# 3.5

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  • Java Slick2d - Mouse picking how to take into account camera

    - by Corey
    When I move it it obviously changes the viewport so my mouse picking is off. My camera is just a float x and y and I use g.translate(-cam.cameraX+400, -cam.cameraY+300); to translate the graphics. I have the numbers hard coded just for testing purposes. How would I take into account the camera so my mouse picking works correctly. double mousetileX = Math.floor((double)mouseX/tiles.tileWidth); double mousetileY = Math.floor((double)mouseY/tiles.tileHeight); double playertileX = Math.floor(playerX/tiles.tileWidth); double playertileY = Math.floor(playerY/tiles.tileHeight); double lengthX = Math.abs((float)playertileX - mousetileX); double lengthY = Math.abs((float)playertileY - mousetileY); double distance = Math.sqrt((lengthX*lengthX)+(lengthY*lengthY)); if(input.isMousePressed(Input.MOUSE_LEFT_BUTTON) && distance < 4) { if(tiles.map[(int)mousetileX][(int)mousetileY] == 1) { tiles.map[(int)mousetileX][(int)mousetileY] = 0; } } That is my mouse picking code

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  • How to mount an Oracle database to new instance?

    - by Vimvq1987
    I have an instance of Oracle 10g R2 installed on Windows Server 2003. This instance was running an database, which does not have any backup. Now the OS went down, and could not repaired, all I got is the running files of the old instance. How can I restore the database from these files to new instance? A step-by-step guide will be much appreciated because I'm new with Oracle. Thank you very much

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  • Is there a way to get docky to launch a new instance?

    - by Matt Briggs
    So i'm really loving the whole gnome-do/docky thing. My question is that on other docks, you can hold down a modifier key to launch a new instance rather then switching to an already opened instance of an app. So lets say I have chrome on the win7 dock first click launches chrome other clicks will focus the opened window shift click will open a new instance of chrome ctrl-shift-click will launch a new instance as admin is there anything similar in docky?

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  • Routes on a sphere surface - Find geodesic?

    - by CaNNaDaRk
    I'm working with some friends on a browser based game where people can move on a 2D map. It's been almost 7 years and still people play this game so we are thinking of a way to give them something new. Since then the game map was a limited plane and people could move from (0, 0) to (MAX_X, MAX_Y) in quantized X and Y increments (just imagine it as a big chessboard). We believe it's time to give it another dimension so, just a couple of weeks ago, we began to wonder how the game could look with other mappings: Unlimited plane with continous movement: this could be a step forward but still i'm not convinced. Toroidal World (continous or quantized movement): sincerely I worked with torus before but this time I want something more... Spherical world with continous movement: this would be great! What we want Users browsers are given a list of coordinates like (latitude, longitude) for each object on the spherical surface map; browsers must then show this in user's screen rendering them inside a web element (canvas maybe? this is not a problem). When people click on the plane we convert the (mouseX, mouseY) to (lat, lng) and send it to the server which has to compute a route between current user's position to the clicked point. What we have We began writing a Java library with many useful maths to work with Rotation Matrices, Quaternions, Euler Angles, Translations, etc. We put it all together and created a program that generates sphere points, renders them and show them to the user inside a JPanel. We managed to catch clicks and translate them to spherical coords and to provide some other useful features like view rotation, scale, translation etc. What we have now is like a little (very little indeed) engine that simulates client and server interaction. Client side shows points on the screen and catches other interactions, server side renders the view and does other calculus like interpolating the route between current position and clicked point. Where is the problem? Obviously we want to have the shortest path to interpolate between the two route points. We use quaternions to interpolate between two points on the surface of the sphere and this seemed to work fine until i noticed that we weren't getting the shortest path on the sphere surface: We though the problem was that the route is calculated as the sum of two rotations about X and Y axis. So we changed the way we calculate the destination quaternion: We get the third angle (the first is latitude, the second is longitude, the third is the rotation about the vector which points toward our current position) which we called orientation. Now that we have the "orientation" angle we rotate Z axis and then use the result vector as the rotation axis for the destination quaternion (you can see the rotation axis in grey): What we got is the correct route (you can see it lays on a great circle), but we get to this ONLY if the starting route point is at latitude, longitude (0, 0) which means the starting vector is (sphereRadius, 0, 0). With the previous version (image 1) we don't get a good result even when startin point is 0, 0, so i think we're moving towards a solution, but the procedure we follow to get this route is a little "strange" maybe? In the following image you get a view of the problem we get when starting point is not (0, 0), as you can see starting point is not the (sphereRadius, 0, 0) vector, and as you can see the destination point (which is correctly drawn!) is not on the route. The magenta point (the one which lays on the route) is the route's ending point rotated about the center of the sphere of (-startLatitude, 0, -startLongitude). This means that if i calculate a rotation matrix and apply it to every point on the route maybe i'll get the real route, but I start to think that there's a better way to do this. Maybe I should try to get the plane through the center of the sphere and the route points, intersect it with the sphere and get the geodesic? But how? Sorry for being way too verbose and maybe for incorrect English but this thing is blowing my mind! EDIT: This code version is related to the first image: public void setRouteStart(double lat, double lng) { EulerAngles tmp = new EulerAngles ( Math.toRadians(lat), 0, -Math.toRadians(lng)); //set route start Quaternion qtStart.setInertialToObject(tmp); //do other stuff like drawing start point... } public void impostaDestinazione(double lat, double lng) { EulerAngles tmp = new AngoliEulero( Math.toRadians(lat), 0, -Math.toRadians(lng)); qtEnd.setInertialToObject(tmp); //do other stuff like drawing dest point... } public V3D interpolate(double totalTime, double t) { double _t = t/totalTime; Quaternion q = Quaternion.Slerp(qtStart, qtEnd, _t); RotationMatrix.inertialQuatToIObject(q); V3D p = matInt.inertialToObject(V3D.Xaxis.scale(sphereRadius)); //other stuff, like drawing point ... return p; } //mostly taken from a book! public static Quaternion Slerp(Quaternion q0, Quaternion q1, double t) { double cosO = q0.dot(q1); double q1w = q1.w; double q1x = q1.x; double q1y = q1.y; double q1z = q1.z; if (cosO < 0.0f) { q1w = -q1w; q1x = -q1x; q1y = -q1y; q1z = -q1z; cosO = -cosO; } double sinO = Math.sqrt(1.0f - cosO*cosO); double O = Math.atan2(sinO, cosO); double oneOverSinO = 1.0f / senoOmega; k0 = Math.sin((1.0f - t) * O) * oneOverSinO; k1 = Math.sin(t * O) * oneOverSinO; // Interpolate return new Quaternion( k0*q0.w + k1*q1w, k0*q0.x + k1*q1x, k0*q0.y + k1*q1y, k0*q0.z + k1*q1z ); } A little dump of what i get (again check image 1): Route info: Sphere radius and center: 200,000, (0.0, 0.0, 0.0) Route start: lat 0,000 °, lng 0,000 ° @v: (200,000, 0,000, 0,000), |v| = 200,000 Route end: lat 30,000 °, lng 30,000 ° @v: (150,000, 86,603, 100,000), |v| = 200,000 Qt dump: (w, x, y, z), rot. angle°, (x, y, z) rot. axis Qt start: (1,000, 0,000, -0,000, 0,000); 0,000 °; (1,000, 0,000, 0,000) Qt end: (0,933, 0,067, -0,250, 0,250); 42,181 °; (0,186, -0,695, 0,695) Route start: lat 30,000 °, lng 10,000 ° @v: (170,574, 30,077, 100,000), |v| = 200,000 Route end: lat 80,000 °, lng -50,000 ° @v: (22,324, -26,604, 196,962), |v| = 200,000 Qt dump: (w, x, y, z), rot. angle°, (x, y, z) rot. axis Qt start: (0,962, 0,023, -0,258, 0,084); 31,586 °; (0,083, -0,947, 0,309) Qt end: (0,694, -0,272, -0,583, -0,324); 92,062 °; (-0,377, -0,809, -0,450)

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  • How do I set up a double domain like domain2.mydomain.com and mydomain.com?

    - by kdavis8
    I would like to set up a server similar to Google's. Their domain acts like a double domain, like you can use these URLS, "play.Google.com" or "apps.Google.com", to go to different sites.. For example, my domain would now be "my_domain.com" but i would like another one to be "domain2.my_domain.com". My question is,what is this officially called and how do i set it up? I'm not sure if you need two servers or just 1;

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  • Why does my .desktop file execute via double click but not from the menu?

    - by Insperatus
    I've installed FTL: Faster Than Light on my girlfriend's Lubuntu machine and created a .desktop file for it. Strangely, the program won't launch via its menu entry under 'Games'. If I navigate to /home/andi/.local/share/applications/ via pcmanfm and double click on FTL Faster Than Light.desktop the game launches without a problem. I know the menu entry is generated through the .desktop file so why won't it launch from the menu? Here's the .desktop file I created: FTL Faster Than Light.desktop

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  • TechDays 2011 : Microsoft a doublé le nombre de ses clients SaaS en France depuis l'été dernier avec 1,2 million d'utilisateurs

    Microsoft a doublé le nombre de ses clients SaaS en France Depuis l'été dernier avec 1,2 million d'utilisateurs A l'occasion de la deuxième journée des TechDays 2011 (placés sous le signe du Cloud), Microsoft met l'accent sur le rôle d'accélérateur de « l'entreprise numérique » joué par les technologies Microsoft qu'elles soient ou non dans le cloud. « Le cloud computing porte en lui la promesse d'accélérer l'accès aux bénéfices de l'entreprise numérique, aussi bien en termes d'infrastructures que de nouveaux usages. Il favorise la transformation des directions informatiques en centre de services et améliore son alignement sur les enjeux métiers, » explique Marc Jalabert, D...

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  • Why can't `main` return a double or String rather than int or void?

    - by sunny
    In many languages such as C, C++, and Java, the main method/function has a return type of void or int, but not double or String. What might be the reasons behind that? I know a little bit that we can't do that because main is called by runtime library and it expects some syntax like int main() or int main(int,char**) so we have to stick to that. So my question is: why does main have the type signature that it has, and not a different one?

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  • Coup d'envoi d'Imagine Cup 2013 : Microsoft double le montant des primes du championnat de l'innovation numérique pour étudiant

    Coup d'envoi d'Imagine Cup 2013 : Microsoft double les primes et modifie la thématique de son championnat de l'innovation numérique pour étudiant C'est parti pour une nouvelle saison d'Imagine Cup, le championnat du monde étudiant de l'innovation numérique organisé par Microsoft. [IMG]http://rdonfack.developpez.com/images/imaginecup20132.jpg[/IMG] Créé en 2002, Imagine Cup permet à des étudiants du monde entier de « s'affronter » pour révéler leur potentiel créatif et entrepreneurial avec une mission : répondre à un ou plusieurs des « Objectifs du Millénaire pour le Développement ». L'édition 2013 de la compétition est ouverte dan...

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  • Steganography Experiment - Trouble hiding message bits in DCT coefficients

    - by JohnHankinson
    I have an application requiring me to be able to embed loss-less data into an image. As such I've been experimenting with steganography, specifically via modification of DCT coefficients as the method I select, apart from being loss-less must also be relatively resilient against format conversion, scaling/DSP etc. From the research I've done thus far this method seems to be the best candidate. I've seen a number of papers on the subject which all seem to neglect specific details (some neglect to mention modification of 0 coefficients, or modification of AC coefficient etc). After combining the findings and making a few modifications of my own which include: 1) Using a more quantized version of the DCT matrix to ensure we only modify coefficients that would still be present should the image be JPEG'ed further or processed (I'm using this in place of simply following a zig-zag pattern). 2) I'm modifying bit 4 instead of the LSB and then based on what the original bit value was adjusting the lower bits to minimize the difference. 3) I'm only modifying the blue channel as it should be the least visible. This process must modify the actual image and not the DCT values stored in file (like jsteg) as there is no guarantee the file will be a JPEG, it may also be opened and re-saved at a later stage in a different format. For added robustness I've included the message multiple times and use the bits that occur most often, I had considered using a QR code as the message data or simply applying the reed-solomon error correction, but for this simple application and given that the "message" in question is usually going to be between 10-32 bytes I have plenty of room to repeat it which should provide sufficient redundancy to recover the true bits. No matter what I do I don't seem to be able to recover the bits at the decode stage. I've tried including / excluding various checks (even if it degrades image quality for the time being). I've tried using fixed point vs. double arithmetic, moving the bit to encode, I suspect that the message bits are being lost during the IDCT back to image. Any thoughts or suggestions on how to get this working would be hugely appreciated. (PS I am aware that the actual DCT/IDCT could be optimized from it's naive On4 operation using row column algorithm, or an FDCT like AAN, but for now it just needs to work :) ) Reference Papers: http://www.lokminglui.com/dct.pdf http://arxiv.org/ftp/arxiv/papers/1006/1006.1186.pdf Code for the Encode/Decode process in C# below: using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Drawing.Imaging; using System.Drawing; namespace ImageKey { public class Encoder { public const int HIDE_BIT_POS = 3; // use bit position 4 (1 << 3). public const int HIDE_COUNT = 16; // Number of times to repeat the message to avoid error. // JPEG Standard Quantization Matrix. // (to get higher quality multiply by (100-quality)/50 .. // for lower than 50 multiply by 50/quality. Then round to integers and clip to ensure only positive integers. public static double[] Q = {16,11,10,16,24,40,51,61, 12,12,14,19,26,58,60,55, 14,13,16,24,40,57,69,56, 14,17,22,29,51,87,80,62, 18,22,37,56,68,109,103,77, 24,35,55,64,81,104,113,92, 49,64,78,87,103,121,120,101, 72,92,95,98,112,100,103,99}; // Maximum qauality quantization matrix (if all 1's doesn't modify coefficients at all). public static double[] Q2 = {1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1}; public static Bitmap Encode(Bitmap b, string key) { Bitmap response = new Bitmap(b.Width, b.Height, PixelFormat.Format32bppArgb); uint imgWidth = ((uint)b.Width) & ~((uint)7); // Maximum usable X resolution (divisible by 8). uint imgHeight = ((uint)b.Height) & ~((uint)7); // Maximum usable Y resolution (divisible by 8). // Start be transferring the unmodified image portions. // As we'll be using slightly less width/height for the encoding process we'll need the edges to be populated. for (int y = 0; y < b.Height; y++) for (int x = 0; x < b.Width; x++) { if( (x >= imgWidth && x < b.Width) || (y>=imgHeight && y < b.Height)) response.SetPixel(x, y, b.GetPixel(x, y)); } // Setup the counters and byte data for the message to encode. StringBuilder sb = new StringBuilder(); for(int i=0;i<HIDE_COUNT;i++) sb.Append(key); byte[] codeBytes = System.Text.Encoding.ASCII.GetBytes(sb.ToString()); int bitofs = 0; // Current bit position we've encoded too. int totalBits = (codeBytes.Length * 8); // Total number of bits to encode. for (int y = 0; y < imgHeight; y += 8) { for (int x = 0; x < imgWidth; x += 8) { int[] redData = GetRedChannelData(b, x, y); int[] greenData = GetGreenChannelData(b, x, y); int[] blueData = GetBlueChannelData(b, x, y); int[] newRedData; int[] newGreenData; int[] newBlueData; if (bitofs < totalBits) { double[] redDCT = DCT(ref redData); double[] greenDCT = DCT(ref greenData); double[] blueDCT = DCT(ref blueData); int[] redDCTI = Quantize(ref redDCT, ref Q2); int[] greenDCTI = Quantize(ref greenDCT, ref Q2); int[] blueDCTI = Quantize(ref blueDCT, ref Q2); int[] blueDCTC = Quantize(ref blueDCT, ref Q); HideBits(ref blueDCTI, ref blueDCTC, ref bitofs, ref totalBits, ref codeBytes); double[] redDCT2 = DeQuantize(ref redDCTI, ref Q2); double[] greenDCT2 = DeQuantize(ref greenDCTI, ref Q2); double[] blueDCT2 = DeQuantize(ref blueDCTI, ref Q2); newRedData = IDCT(ref redDCT2); newGreenData = IDCT(ref greenDCT2); newBlueData = IDCT(ref blueDCT2); } else { newRedData = redData; newGreenData = greenData; newBlueData = blueData; } MapToRGBRange(ref newRedData); MapToRGBRange(ref newGreenData); MapToRGBRange(ref newBlueData); for(int dy=0;dy<8;dy++) { for(int dx=0;dx<8;dx++) { int col = (0xff<<24) + (newRedData[dx+(dy*8)]<<16) + (newGreenData[dx+(dy*8)]<<8) + (newBlueData[dx+(dy*8)]); response.SetPixel(x+dx,y+dy,Color.FromArgb(col)); } } } } if (bitofs < totalBits) throw new Exception("Failed to encode data - insufficient cover image coefficients"); return (response); } public static void HideBits(ref int[] DCTMatrix, ref int[] CMatrix, ref int bitofs, ref int totalBits, ref byte[] codeBytes) { int tempValue = 0; for (int u = 0; u < 8; u++) { for (int v = 0; v < 8; v++) { if ( (u != 0 || v != 0) && CMatrix[v+(u*8)] != 0 && DCTMatrix[v+(u*8)] != 0) { if (bitofs < totalBits) { tempValue = DCTMatrix[v + (u * 8)]; int bytePos = (bitofs) >> 3; int bitPos = (bitofs) % 8; byte mask = (byte)(1 << bitPos); byte value = (byte)((codeBytes[bytePos] & mask) >> bitPos); // 0 or 1. if (value == 0) { int a = DCTMatrix[v + (u * 8)] & (1 << HIDE_BIT_POS); if (a != 0) DCTMatrix[v + (u * 8)] |= (1 << HIDE_BIT_POS) - 1; DCTMatrix[v + (u * 8)] &= ~(1 << HIDE_BIT_POS); } else if (value == 1) { int a = DCTMatrix[v + (u * 8)] & (1 << HIDE_BIT_POS); if (a == 0) DCTMatrix[v + (u * 8)] &= ~((1 << HIDE_BIT_POS) - 1); DCTMatrix[v + (u * 8)] |= (1 << HIDE_BIT_POS); } if (DCTMatrix[v + (u * 8)] != 0) bitofs++; else DCTMatrix[v + (u * 8)] = tempValue; } } } } } public static void MapToRGBRange(ref int[] data) { for(int i=0;i<data.Length;i++) { data[i] += 128; if(data[i] < 0) data[i] = 0; else if(data[i] > 255) data[i] = 255; } } public static int[] GetRedChannelData(Bitmap b, int sx, int sy) { int[] data = new int[8 * 8]; for (int y = sy; y < (sy + 8); y++) { for (int x = sx; x < (sx + 8); x++) { uint col = (uint)b.GetPixel(x,y).ToArgb(); data[(x - sx) + ((y - sy) * 8)] = (int)((col >> 16) & 0xff) - 128; } } return (data); } public static int[] GetGreenChannelData(Bitmap b, int sx, int sy) { int[] data = new int[8 * 8]; for (int y = sy; y < (sy + 8); y++) { for (int x = sx; x < (sx + 8); x++) { uint col = (uint)b.GetPixel(x, y).ToArgb(); data[(x - sx) + ((y - sy) * 8)] = (int)((col >> 8) & 0xff) - 128; } } return (data); } public static int[] GetBlueChannelData(Bitmap b, int sx, int sy) { int[] data = new int[8 * 8]; for (int y = sy; y < (sy + 8); y++) { for (int x = sx; x < (sx + 8); x++) { uint col = (uint)b.GetPixel(x, y).ToArgb(); data[(x - sx) + ((y - sy) * 8)] = (int)((col >> 0) & 0xff) - 128; } } return (data); } public static int[] Quantize(ref double[] DCTMatrix, ref double[] Q) { int[] DCTMatrixOut = new int[8*8]; for (int u = 0; u < 8; u++) { for (int v = 0; v < 8; v++) { DCTMatrixOut[v + (u * 8)] = (int)Math.Round(DCTMatrix[v + (u * 8)] / Q[v + (u * 8)]); } } return(DCTMatrixOut); } public static double[] DeQuantize(ref int[] DCTMatrix, ref double[] Q) { double[] DCTMatrixOut = new double[8*8]; for (int u = 0; u < 8; u++) { for (int v = 0; v < 8; v++) { DCTMatrixOut[v + (u * 8)] = (double)DCTMatrix[v + (u * 8)] * Q[v + (u * 8)]; } } return(DCTMatrixOut); } public static double[] DCT(ref int[] data) { double[] DCTMatrix = new double[8 * 8]; for (int v = 0; v < 8; v++) { for (int u = 0; u < 8; u++) { double cu = 1; if (u == 0) cu = (1.0 / Math.Sqrt(2.0)); double cv = 1; if (v == 0) cv = (1.0 / Math.Sqrt(2.0)); double sum = 0.0; for (int y = 0; y < 8; y++) { for (int x = 0; x < 8; x++) { double s = data[x + (y * 8)]; double dctVal = Math.Cos((2 * y + 1) * v * Math.PI / 16) * Math.Cos((2 * x + 1) * u * Math.PI / 16); sum += s * dctVal; } } DCTMatrix[u + (v * 8)] = (0.25 * cu * cv * sum); } } return (DCTMatrix); } public static int[] IDCT(ref double[] DCTMatrix) { int[] Matrix = new int[8 * 8]; for (int y = 0; y < 8; y++) { for (int x = 0; x < 8; x++) { double sum = 0; for (int v = 0; v < 8; v++) { for (int u = 0; u < 8; u++) { double cu = 1; if (u == 0) cu = (1.0 / Math.Sqrt(2.0)); double cv = 1; if (v == 0) cv = (1.0 / Math.Sqrt(2.0)); double idctVal = (cu * cv) / 4.0 * Math.Cos((2 * y + 1) * v * Math.PI / 16) * Math.Cos((2 * x + 1) * u * Math.PI / 16); sum += (DCTMatrix[u + (v * 8)] * idctVal); } } Matrix[x + (y * 8)] = (int)Math.Round(sum); } } return (Matrix); } } public class Decoder { public static string Decode(Bitmap b, int expectedLength) { expectedLength *= Encoder.HIDE_COUNT; uint imgWidth = ((uint)b.Width) & ~((uint)7); // Maximum usable X resolution (divisible by 8). uint imgHeight = ((uint)b.Height) & ~((uint)7); // Maximum usable Y resolution (divisible by 8). // Setup the counters and byte data for the message to decode. byte[] codeBytes = new byte[expectedLength]; byte[] outBytes = new byte[expectedLength / Encoder.HIDE_COUNT]; int bitofs = 0; // Current bit position we've decoded too. int totalBits = (codeBytes.Length * 8); // Total number of bits to decode. for (int y = 0; y < imgHeight; y += 8) { for (int x = 0; x < imgWidth; x += 8) { int[] blueData = ImageKey.Encoder.GetBlueChannelData(b, x, y); double[] blueDCT = ImageKey.Encoder.DCT(ref blueData); int[] blueDCTI = ImageKey.Encoder.Quantize(ref blueDCT, ref Encoder.Q2); int[] blueDCTC = ImageKey.Encoder.Quantize(ref blueDCT, ref Encoder.Q); if (bitofs < totalBits) GetBits(ref blueDCTI, ref blueDCTC, ref bitofs, ref totalBits, ref codeBytes); } } bitofs = 0; for (int i = 0; i < (expectedLength / Encoder.HIDE_COUNT) * 8; i++) { int bytePos = (bitofs) >> 3; int bitPos = (bitofs) % 8; byte mask = (byte)(1 << bitPos); List<int> values = new List<int>(); int zeroCount = 0; int oneCount = 0; for (int j = 0; j < Encoder.HIDE_COUNT; j++) { int val = (codeBytes[bytePos + ((expectedLength / Encoder.HIDE_COUNT) * j)] & mask) >> bitPos; values.Add(val); if (val == 0) zeroCount++; else oneCount++; } if (oneCount >= zeroCount) outBytes[bytePos] |= mask; bitofs++; values.Clear(); } return (System.Text.Encoding.ASCII.GetString(outBytes)); } public static void GetBits(ref int[] DCTMatrix, ref int[] CMatrix, ref int bitofs, ref int totalBits, ref byte[] codeBytes) { for (int u = 0; u < 8; u++) { for (int v = 0; v < 8; v++) { if ((u != 0 || v != 0) && CMatrix[v + (u * 8)] != 0 && DCTMatrix[v + (u * 8)] != 0) { if (bitofs < totalBits) { int bytePos = (bitofs) >> 3; int bitPos = (bitofs) % 8; byte mask = (byte)(1 << bitPos); int value = DCTMatrix[v + (u * 8)] & (1 << Encoder.HIDE_BIT_POS); if (value != 0) codeBytes[bytePos] |= mask; bitofs++; } } } } } } } UPDATE: By switching to using a QR Code as the source message and swapping a pair of coefficients in each block instead of bit manipulation I've been able to get the message to survive the transform. However to get the message to come through without corruption I have to adjust both coefficients as well as swap them. For example swapping (3,4) and (4,3) in the DCT matrix and then respectively adding 8 and subtracting 8 as an arbitrary constant seems to work. This survives a re-JPEG'ing of 96 but any form of scaling/cropping destroys the message again. I was hoping that by operating on mid to low frequency values that the message would be preserved even under some light image manipulation.

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  • C++ Templates: implicit conversion, no matching function for call to ctor

    - by noname
    template<class T> class test { public: test() { } test(T& e) { } }; int main() { test<double> d(4.3); return 0; } Compiled using g++ 4.4.1 with the following errors: g++ test.cpp -Wall -o test.exe test.cpp: In function 'int main()': test.cpp:18: error: no matching function for call to 'test<double>::test(double) ' test.cpp:9: note: candidates are: test<T>::test(T&) [with T = double] test.cpp:5: note: test<T>::test() [with T = double] test.cpp:3: note: test<double>::test(const test<double>&) make: *** [test.exe] Error 1 However, this works: double a=1.1; test<double> d(a); Why is this happing? Is it possible that g++ cannot implicitly convert literal expression 1.1 to double? Thanks.

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  • How to get Distance Kilometer in android?

    - by user1787493
    i am very new to Google maps i want calculate the distance between two places in android .for that i get the two places lat and lag positions for that i write the following code: private double getDistance(double lat1, double lat2, double lon1, double lon2) { double dLat = Math.toRadians(lat2 - lat1); double dLon = Math.toRadians(lon2 - lon1); double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2)) * Math.sin(dLon / 2) * Math.sin(dLon / 2); double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a)); double temp = 6371 * c; temp=temp*0.621; return temp; } the above code cant give the accurate distance between two places .what is the another way to find distance please give me any suggestions thanks in advance....

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  • Annoying flickering of vertices and edges (possible z-fighting)

    - by Belgin
    I'm trying to make a software z-buffer implementation, however, after I generate the z-buffer and proceed with the vertex culling, I get pretty severe discrepancies between the vertex depth and the depth of the buffer at their projected coordinates on the screen (i.e. zbuffer[v.xp][v.yp] != v.z, where xp and yp are the projected x and y coordinates of the vertex v), sometimes by a small fraction of a unit and sometimes by 2 or 3 units. Here's what I think is happening: Each triangle's data structure holds the plane's (that is defined by the triangle) coefficients (a, b, c, d) computed from its three vertices from their normal: void computeNormal(Vertex *v1, Vertex *v2, Vertex *v3, double *a, double *b, double *c) { double a1 = v1 -> x - v2 -> x; double a2 = v1 -> y - v2 -> y; double a3 = v1 -> z - v2 -> z; double b1 = v3 -> x - v2 -> x; double b2 = v3 -> y - v2 -> y; double b3 = v3 -> z - v2 -> z; *a = a2*b3 - a3*b2; *b = -(a1*b3 - a3*b1); *c = a1*b2 - a2*b1; } void computePlane(Poly *p) { double x = p -> verts[0] -> x; double y = p -> verts[0] -> y; double z = p -> verts[0] -> z; computeNormal(p -> verts[0], p -> verts[1], p -> verts[2], &p -> a, &p -> b, &p -> c); p -> d = p -> a * x + p -> b * y + p -> c * z; } The z-buffer just holds the smallest depth at the respective xy coordinate by somewhat casting rays to the polygon (I haven't quite got interpolation right yet so I'm using this slower method until I do) and determining the z coordinate from the reversed perspective projection formulas (which I got from here: double z = -(b*Ez*y + a*Ez*x - d*Ez)/(b*y + a*x + c*Ez - b*Ey - a*Ex); Where x and y are the pixel's coordinates on the screen; a, b, c, and d are the planes coefficients; Ex, Ey, and Ez are the eye's (camera's) coordinates. This last formula does not accurately give the exact vertices' z coordinate at their projected x and y coordinates on the screen, probably because of some floating point inaccuracy (i.e. I've seen it return something like 3.001 when the vertex's z-coordinate was actually 2.998). Here is the portion of code that hides the vertices that shouldn't be visible: for(i = 0; i < shape.nverts; ++i) { double dist = shape.verts[i].z; if(z_buffer[shape.verts[i].yp][shape.verts[i].xp].z < dist) shape.verts[i].visible = 0; else shape.verts[i].visible = 1; } How do I solve this issue? EDIT I've implemented the near and far planes of the frustum, with 24 bit accuracy, and now I have some questions: Is this what I have to do this in order to resolve the flickering? When I compare the z value of the vertex with the z value in the buffer, do I have to convert the z value of the vertex to z' using the formula, or do I convert the value in the buffer back to the original z, and how do I do that? What are some decent values for near and far? Thanks in advance.

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  • What type of amazon instance should I use and do I need auto scaling and load balancing?

    - by Navetz
    Hi I am looking to release a website that will initially have large amounts of uploads from users. The first will be 65GB and the rest will probably be close to 1TB. They could happen simultaneously. My question is what type of amazon server instance would be best for this? The website is just being released so the traffic wont be very high. I have been using a micro instance for development but it is time to launch and I need more power. Should I use auto scaling and a load balancer to increase the number of instances when I need it or Will a small or medium instance do the trick? If I do use auto scaling and load balancing how do I handle things like sessions and the database/file lookups? Does one instance become the primary instance and the rest become clones?

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  • Make Ms Word activate window of file if it is already open when I double click the file's icon?

    - by barlop
    When I try to open a word document that is already open, I want it to just activate the window where the file is open. How can I do that? sometimes it takes time to check if an ms word document is already open, I don't to have to have to check through a bunch of open word documents to see if it's in there or not, I just want to double click the icon of a word document, and if it's open then go to it, if not then open it. With the doc/docx or shortcut to the doc/docx , I have some files where when I double click , it activates it when already open. I have other files where double clicking will bring up a "file in use" dialog box. I can't find what is the cause. I want it to always activate the window rather than reopen it. update- maybe that is default behaviour to activate when already open, and after a crash I had that stopped. i'll try deleting the working files and starting ms word again, idea from here

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  • New Features and Changes in OIM11gR2

    - by Abhishek Tripathi
    WEB CONSOLEs in OIM 11gR2 ** In 11gR1 there were 3 Admin Web Consoles : ·         Self Service Console ·         Administration Console and ·         Advanced Administration Console accessible Whereas in OIM 11gR2 , Self Service and Administration Console have are now combined and now called as Identity Self Service Console http://host:port/identity  This console has 3 features in it for managing self profile (My Profile), Managing Requests like requesting for App Instances and Approving requests (Requests) and General Administration tasks of creating/managing users, roles, organization, attestation etc (Administration) ** In OIM 11gR2 – new console sysadmin has been added Administrators which includes some of the design console functions apart from general administrations features. http://host:port/sysadmin   Application Instances Application instance is the object that is to be provisioned to a user. Application Instances are checked out in the catalog and user can request for application instances via catalog. ·         In OIM 11gR2 resources and entitlements are bundled in Application Instance which user can select and request from catalog.  ·         Application instance is a combination of IT Resource and RO. So, you cannot create another App Instance with the same RO & IT Resource if it already exists for some other App Instance. One of these ( RO or IT Resource) must have a different name. ·         If you want that users of a particular Organization should be able to request for an Application instances through catalog then App Instances must be attached to that particular Organization. ·         Application instance can be associated with multiple organizations. ·         An application instance can also have entitlements associated with it. Entitlement can include Roles/Groups or Responsibility. ·         Application Instance are published to the catalog by a scheduled task “Catalog Synchronization Job” ·         Application Instance can have child/ parent application instance where child application instance inherits all attributes of parent application instance. Important point to remember with Application Instance If you delete the application Instance in OIM 11gR2 and create a new one with the same name, OIM will not allow doing so. It throws error saying Application Instance already exists with same Resource Object and IT resource. This is because there is still some reference that is not removed in OIM for deleted application Instance.  So to completely delete your application Instance from OIM, you must: 1. Delete the app Instance from sysadmin console. 2. Run the App Instance Post Delete Processing Job in Revoke/Delete mode. 3. Run the Catalog Synchronization job. Once done, you should be able to create a new App instance with the previous RO & IT Resouce name.   Catalog  Catalog allows users to request Roles, Application Instance, and Entitlements in an Application. Catalog Items – Roles, Application Instance and Entitlements that can be requested via catalog are called as catalog items. Detailed Information ( attributes of Catalog item)  Category – Each catalog item is associated with one and only one category. Catalog Administrators can provide a value for catalog item. ·         Tags – are search keywords helpful in searching Catalog. When users search the Catalog, the search is performed against the tags. To define a tag, go to Catalog->Search the resource-> select the resource-> update the tag field with custom search keyword. Tags are of three types: a) Auto-generated Tags: The Catalog synchronization process auto-tags the Catalog Item using the Item Type, Item Name and Item Display Name b) User-defined Tags: User-defined Tags are additional keywords entered by the Catalog Administrator. c) Arbitrary Tags: While defining a metadata if user has marked that metadata as searchable, then that will also be part of tags.   Sandbox  Sanbox is a new feature introduced in OIM11gR2. This serves as a temporary development environment for UI customizations so that they don’t affect other users before they are published and linked to existing OIM UI. All UI customizations should be done inside a sandbox, this ensures that your changes/modifications don’t affect other users until you have finalized the changes and customization is complete. Once UI customization is completed, the Sandbox must be published for the customizations to be merged into existing UI and available to other users. Creating and activating a sandbox is mandatory for customizing the UI by .Without an active sandbox, OIM does not allow to customize any page. a)      Before you perform any activity in OIM (like Create/Modify Forms, Custom Attribute, creating application instances, adding roles/attributes to catalog) you must create a Sand Box and activate it. b)      One can create multiple sandboxes in OIM but only one sandbox can be active at any given time. c)      You can export/import the sandbox to move the changes from one environment to the other. Creating Sandbox To create sandbox, login to identity manager self service (/identity) or System Administration (/sysadmin) and click on top right of link “Sandboxes” and then click on Create SandBox. Publishing Sandbox Before you publish a sandbox, it is recommended to backup MDS. Use /EM to backup MDS by following the steps below : Creating MDS Backup 1.      Login to Oracle Enterprise Manager as the administrator. 2.      On the landing page, click oracle.iam.console.identity.self-service.ear(V2.0). 3.      From the Application Deployment menu at the top, select MDS configuration. 4.      Under Export, select the Export metadata documents to an archive on the machine where this web browser is running option, and then click Export. All the metadata is exported in a ZIP file.   Creating Password Policy through Admin Console : In 11gR1 and previous versions password policies could be created & applied via OIM Design Console only. From OIM11gR2 onwards, Password Policies can be created and assigned using Admin Console as well.  

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  • Is having a single `IndexWriter` instance in Lucene a good idea?

    - by Dragos
    I am trying to understand how Lucene should be used. From what I have read, creating an IndexReader is costly, so using a Search Manager shoulg be the right choice. However, a SearchManager should be produced by a NRTManager(which, by the way, should replace the IndexWriter for every add or delete operation performed). But in order to have a NRTManager, I should first have an IndexWriter, and here comes my problem. The documentation says: an IndexWriter is thread-safe the constructor of this class takes a Directory object, so it seems creating an instace should be costly(as in the case of an IndexReader) all changes are buffered and flushed periodically(so they seem to encourage using a single instance) but: the changes, although flushed will only be visible after commit or close after finished making updates(add/delete), the instance should be closed I also found this: http://stackoverflow.com/questions/5374419/forgot-to-close-the-lucene-indexwriter-after-adding-documents-to-the-index where it is said that not closing a writer might ruin everything So what am I really supposed to do? Is having a single IndexWriter instance a good idea (make only commit and never close it)? EDIT: What is more, if I use NRTManager, how can I make acommit`? Is it even possible?

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  • AWS instance went down for restart, came back up and has been "Waiting for network configuration... " for 12 hours

    - by kavisiegel
    What happened was about a month ago, I created a new instance, re-configured everything, and mounted the old instances drive to the new one. I then detached the old drive from the instance, but it was still mounted, so it errored out. Now, come the outage last month, and when the instance boots back up - the drive isn't there, because in the downtime, it dismounted. It hangs because the fstab is looking for it. I get word that the server's not up today, I check the logs, re-attach the drive and restart. Now I'm getting "Waiting for network configuration..." and it doesn't seem to be doing anything. Some googling told me that I'm going to need to start from zero again, which I don't think is right. I created a new instance, which booted no problem, then I stopped it and swapped the two old drives into the new instance. Still the same error. Using the fresh AMI, it worked. I figure it's just a misconfigured Amazon file. I can attach the drive to a functioning instance on the same AMI and copy some files over, then try again - but I don't know where to even start or what files to check.

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