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  • [Facebook Graph API - Android] I want to know the HTTPSConnection redirected to which URL?

    - by Mohammad Abdelaziz
    I am building an application that uses the Facebook Graph API. To get the access token I should send the following request https://graph.facebook.com/oauth/authorize? client_id=...& redirect_uri=http://www.example.com/callback It redirects to the redirect_uri with the code to be used as access token. How can I capture that the HttpsURLConnection is redirected and how to get the code? Is it possible or I need to have server that gets the access token?

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  • How can I store this kind of graph in neo4j for fast traversal?

    - by James
    This is a graph whose nodes exist in many connected components at once because a node's relationships are a collection of edge groups such that only one edge per edge group can be present at once. I need to be able to find all of the connected components that a node exists in. What would be the best way to store this graph in neo4j to quickly find all of the connected components that a node exists in? Is there a way to use the built in traversals to do this? Also: is there a name for this kind of graph? I'd appreciate any help/ideas. Update: Sorry for not being clear. All nodes are of the same type. Nodes have a variable number of edge groups. Exactly one edge from each edge group needs to be chosen for a particular connected component. I'm going to try to explain through example: Node x1 is related to: (x2 or x3 or x4) AND (x5 or x6) AND (x7) Node x2 is related to: (x8) AND (x9 or x10) So x1's first edge group is (x2, x3, x4), its second edge group is (x5, x6), and its third edge group is (x7). So here are a few connected components that x1 exists in: CC1: x1 is related to: x2, x5, x7 x2 is related to: x8 x9 CC2: x1 is related to: x2, x6, x7 x2 is related to: x8, x9 CC3: x1 is related to: x3, x5, x7 CC4: x1 is related to: x3, x6, x7 etc. I'm grateful for your help in this.

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  • What algorithms do "the big ones" use to cluster news?

    - by marco92w
    I want to cluster texts for a news website. At the moment I use this algorithm to find the related articles. But I found out that PHP's similar_text() gives very good results, too. What sort of algorithms do "the big ones", Google News, Topix, Techmeme, Wikio, Megite etc., use? Of course, you don't know exactly how the algorithms work. It's secret. But maybe someone knows approximately the way they work? The algorithm I use at the moment is very slow. It only compares two articles. So for having the relations between 5,000 articles you need about 12,500,000 comparisons. This is quite a lot. Are there alternatives to reduce the number of necessary comparisons? [I don't look for improvements for my algorithm.] What do "the big ones" do? I'm sure they don't always compare one article to another and this 12,500,000 times for 5,000 news. It would be great if somebody can say something about this topic.

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  • problem with evolutionary algorithms degrading into simulated annealing: mutation too small?

    - by Schnalle
    i have a problem understanding evolutionary algorithms. i tried using this technique several times, but i always ran into the same problem: degeneration into simulated annealing. lets say my initial population, with fitness in brackets, is: A (7), B (9), C (14), D (19) after mating and mutation i have following children: AB (8.3), AC (12.2), AD (14.1), BC(11), BD (14.7), CD (17) after elimination of the weakest, we get A, AB, B, AC next turn, AB will mate again with a result around 8, pushing AC out. next turn, AB again, pushing B out (assuming mutation changes fitness mostly in the 1 range). now, after only a few turns the pool is populated with the originally fittest candidates (A, B) and mutations of those two (AB). this happens regardless of the size of the initial pool, it just takes a bit longer. say, with an initial population of 50 it takes 50 turns, then all others are eliminated, turning the whole setup in a more complicated simulated annealing. in the beginning i also mated canditates with themselves, worsening the problem. so, what do i miss? are my mutation rates simply too small and will it go away if i increase them? here's the project i'm using it for: http://stefan.schallerl.com/simuan-grid-grad/ yeah, the code is buggy and the interface sucks, but i'm too lazy to fix it right now - and be careful, it may lock up your browser. better use chrome, even thought firefox is not slower than chrome for once (probably the tracing for the image comparison pays off, yay!). if anyone is interested, the code can be found here. here i just dropped the ev-alg idea and went for simulated annealing. ps: i'm not even sure about simulated annealing - it is like evolutionary algorithms, just with a population size of one, right?

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  • How to return array of C++ objects from a PHP extension

    - by John Factorial
    I need to have my PHP extension return an array of objects, but I can't seem to figure out how to do this. I have a Graph object written in C++. Graph.getNodes() returns a std::map<int, Node*>. Here's the code I have currently: struct node_object { zend_object std; Node *node; }; zend_class_entry *node_ce; then PHP_METHOD(Graph, getNodes) { Graph *graph; GET_GRAPH(graph, obj) // a macro I wrote to populate graph node_object* n; zval* node_zval; if (obj == NULL) { RETURN_NULL(); } if (object_init_ex(node_zval, node_ce) != SUCCESS) { RETURN_NULL(); } std::map nodes = graph-getNodes(); array_init(return_value); for (std::map::iterator i = nodes.begin(); i != nodes.end(); ++i) { php_printf("X"); n = (node_object*) zend_object_store_get_object(node_zval TSRMLS_CC); n-node = i-second; add_index_zval(return_value, i-first, node_zval); } php_printf("]"); } When i run php -r '$g = new Graph(); $g->getNodes();' I get the output XX]Segmentation fault meaning the getNodes() function loops successfully through my 2-node list, returns, then segfaults. What am I doing wrong?

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  • Qt Graphics et performance - velours et QML Scene Graph, un article de Gunnar, traduit par Thibaut Cuvelier

    Le 11 décembre 2009, la documentation de QPainter subissait un énorme ajout concernant l'optimisation de son utilisation. En effet, le bon usage de cet outil n'était pas accessible à tous, il n'était pas présenté dans la documentation. Ceci ne fut qu'un prétexte à une série d'articles sur l'optimisation de QPainter et de Qt Graphics en général. Voici donc le premier article de cette série, les autres sont en préparation : Qt Graphics et performances : ce qui est critique et ce qui ne l'est pas Pensez-vous que cet ajout à la documentation de QPainter sera utile ? Trouvez-vous les performances de vos applications trop faibles ?...

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  • What is the difference between these two nloglog(n) sorting algorithms? (Andersson et al., 1995 vs.

    - by Yktula
    Swanepoel's comment here lead me to this paper. Then, searching for an implementation in C, I came across this, which referenced another paper on an algorithm described here. Both papers describe integer sorting algorithms that run in O(nloglog(n)) time. What is the difference between the two? Have there been any more recent findings about this topic? Andersson et al., 1995 Han, 2004

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  • What problems have you solved using genetic algorithms/genetic programming?

    - by knorv
    Genetic algorithms (GA) and genetic programming (GP) are interesting areas of research. I'd like to know about specific problems you - the SO reader - have solved using GA/GP and what libraries/frameworks you used if you didn't roll your own. Questions: What problems have you used GA/GP to solve? What libraries/frameworks did you use? I'm looking for first-hand experiences, so please do not answer unless you have that.

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  • How to customize the renders in prefuse. Problem in customize images in prefuse layout

    - by user324926
    HI all, I have written a java application to show the images in different layouts. I am able to show it different layout correctly but some times the images are overlapped. Can you please help me, how to solve this problem. My code is given below `import javax.swing.JFrame; import java.awt.image.BufferedImage; import javax.imageio.ImageIO; import java.util.; import java.io.; import java.awt.Font; import prefuse.Constants; import prefuse.Display; import prefuse.Visualization; import prefuse.action.ActionList; import prefuse.action.RepaintAction; import prefuse.action.assignment.ColorAction; import prefuse.action.assignment.FontAction; import prefuse.action.assignment.DataColorAction; import prefuse.action.layout.graph.ForceDirectedLayout; import prefuse.action.layout.graph.; import prefuse.action.layout.; import prefuse.activity.Activity; import prefuse.controls.DragControl; import prefuse.controls.PanControl; import prefuse.controls.ZoomControl; import prefuse.data.Graph; import prefuse.data.io.DataIOException; import prefuse.data.io.GraphMLReader; import prefuse.render.DefaultRendererFactory; import prefuse.render.LabelRenderer; import prefuse.util.ColorLib; import prefuse.visual.VisualItem; import prefuse.visual.*; import prefuse.util.FontLib; import prefuse.action.assignment.DataSizeAction; import prefuse.data.*; import prefuse.render.ImageFactory; public class LayoutExample { public static void main(String[] argv) throws Exception { Graph graph = null; try { graph = new GraphMLReader().readGraph("/graphs.xml"); } catch ( DataIOException e ) { e.printStackTrace(); System.err.println("Error loading graph. Exiting..."); System.exit(1); } ImageFactory imageFactory = new ImageFactory(100,100); try { //load images and construct imageFactory. String images[] = new String[3]; images[0] = "data/images/switch.png"; images[1] = "data/images/ip_network.png"; images[2] = "data/images/router.png"; String[] names = new String[] {"Switch","Network","Router"}; BufferedImage img = null; for(int i=0; i < images.length ; i++) { try { img = ImageIO.read(new File(images[i])); imageFactory.addImage(names[i],img); } catch (IOException e){ } } } catch(Exception exp) { } Visualization vis = new Visualization(); vis.add("graph", graph); LabelRenderer nodeRenderer = new LabelRenderer("name", "type"); nodeRenderer.setVerticalAlignment(Constants.BOTTOM); nodeRenderer.setHorizontalPadding(0); nodeRenderer.setVerticalPadding(0); nodeRenderer.setImagePosition(Constants.TOP); nodeRenderer.setMaxImageDimensions(100,100); DefaultRendererFactory drf = new DefaultRendererFactory(); drf.setDefaultRenderer(nodeRenderer); vis.setRendererFactory(drf); ColorAction nText = new ColorAction("graph.nodes", VisualItem.TEXTCOLOR); nText.setDefaultColor(ColorLib.gray(100)); ColorAction nEdges = new ColorAction("graph.edges", VisualItem.STROKECOLOR); nEdges.setDefaultColor(ColorLib.gray(100)); // bundle the color actions ActionList draw = new ActionList(); //MAD - changing the size of the nodes dependent on the weight of the people final DataSizeAction dsa = new DataSizeAction("graph.nodes","size"); draw.add(dsa); draw.add(nText); draw.add(new FontAction("graph.nodes", FontLib.getFont("Tahoma",Font.BOLD, 12))); draw.add(nEdges); vis.putAction("draw", draw); ActionList layout = new ActionList(Activity.DEFAULT_STEP_TIME); BalloonTreeLayout balloonlayout = new BalloonTreeLayout("graph",50); layout.add(balloonlayout); Display d = new Display(vis); vis.putAction("layout", layout); // start up the animated layout vis.run("draw"); vis.run("layout"); d.addControlListener(new DragControl()); // pan with left-click drag on background d.addControlListener(new PanControl()); // zoom with right-click drag d.addControlListener(new ZoomControl()); // -- 6. launch the visualization ------------------------------------- // create a new window to hold the visualization JFrame frame = new JFrame("prefuse example"); // ensure application exits when window is closed frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.add(d); frame.pack(); // layout components in window frame.setVisible(true); // show the window } } ` Can anyone please let me know how to customize the image sizes / renders insuch way that images won't overlapped. Thanks R.Ravikumar

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  • Are there any well known algorithms to detect the presence of names?

    - by Rhubarb
    For example, given a string: "Bob went fishing with his friend Jim Smith." Bob and Jim Smith are both names, but bob and smith are both words. Weren't for them being uppercase, there would be less indication of this outside of our knowledge of the sentence. Without doing grammar analysis, are there any well known algorithms for detecting the presence of names, at least Western names?

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  • graphviz segmentation fault

    - by LucaB
    Hi I'm building a graph with many nodes, around 3000. I wrote a simple python program to do the trick with graphviz, but it gives me segmentation fault and I don't know why, if the graph is too big or if i'm missing something. The code is: #!/usr/bin/env python # Import graphviz import sys sys.path.append('..') sys.path.append('/usr/lib/graphviz') import gv # Import pygraph from pygraph.classes.graph import graph from pygraph.classes.digraph import digraph from pygraph.algorithms.searching import breadth_first_search from pygraph.readwrite.dot import write # Graph creation gr = graph() file = open('nodes.dat', 'r') line = file.readline() while line: gr.add_nodes([line[0:-1]]) line = file.readline() file.close() print 'nodes finished, beginning edges' edges = open('edges_ok.dat', 'r') edge = edges.readline() while edge: gr.add_edge((edge.split()[0], edge.split()[1])) edge = edges.readline() edges.close() print 'edges finished' print 'Drawing' # Draw as PNG dot = write(gr) gvv = gv.readstring(dot) gv.layout(gvv,'dot') gv.render(gvv,'svg','graph.svg') and it crashes at the gv.layout() call. The files are somthing like: nodes: node1 node2 node3 edges_ok: node1 node2 node2 node3

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  • Complex Entity Framework linked-graphs issue: how to limit change set / break the graph?

    - by Hightechrider
    I have an EDMX containing Sentences, and Words, say and a Sentence contains three Words, say. Appropriate FK relationships exist between the tables. I create some words: Word word1 = new Word(); Word word2 = ... I build a Sentence: Sentence x = new Sentence (word1, word2, word3); I build another Sentence: Sentence y = new Sentence (word1, word4, word5); I try to save x to the database, but EF builds a change set that includes everything, including y, word4 and word5 that aren't ready to save to the database. When SaveChanges() happens it throws an exception: Unable to determine the principal end of the ... relationship. Multiple added entities may have the same primary key. I think it does this because Word has an EntityCollection<Sentence> on it from the FK relationship between the two tables, and thus Sentence y is inextricably linked to Sentence x through word1. So I remove the Navigation Property Sentences from Word and try again. It still tries to put the entire graph into the change set. What suggestions do the Entity Framework experts have for ways to break this connection. Essentially what I want is a one-way mapping from Sentence to Word; I don't want an EntityCollection<Sentence> on Word and I don't want the object graph to get intertwined like this. Code sample: This puts two sentences into the database because Verb1 links them and EF explores the entire graph of existing objects and added objects when you do Add/SaveChanges. Word subject1 = new Word(){ Text = "Subject1"}; Word subject2 = new Word(){ Text = "Subject2"}; Word verb1 = new Word(){ Text = "Verb11"}; Word object1 = new Word(){ Text = "Object1"}; Word object2 = new Word(){ Text = "Object2"}; Sentence s1 = new Sentence(){Subject = subject1, Verb=verb1, Object=object1}; Sentence s2 = new Sentence(){Subject=subject2, Verb=verb1, Object=object2}; context.AddToSentences(s1); context.SaveChanges(); foreach (var s in context.Sentences) { Console.WriteLine(s.Subject + " " + s.Verb + " " + s.Object); }

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  • Do you know of a free .Net component for visual flow model graph design and editing?

    - by Ivan
    An app (C#4, WinForms, Entity Framework, SQL Server 2008) of mine maintains a graph of interconnected objects, each having some simple member fields and a set of many directed (in and out) one-to-one links to other objects. I'd like to offer a user an ability to view and edit this graph visually some way, creating and removing connections, modifying objects attributes values and introducing/dropping objects. I suppose there has to be a framework (at list a primitive kind of) for this as visual model design tools are pretty common to meet. Do you know one?

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  • What data structures and algorithms are applied within data warehouse cubes?

    - by Jeff Meatball Yang
    I understand that cubes are optimized data structures for aggregating and "slicing" large amounts of data. I just don't know how they are implemented. I can imagine a lot of this technology is proprietary, but are there any resources that I could use to start implementing my own cube technology? Set theory and lots of math are probably involved (and welcome as suggestions!), but I'm primarily interested in implementations: the data structures and query algorithms. Thanks!

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  • Facebook Graph API: Feed publishing showing up as link type instead of status?

    - by Redth
    So I'm publishing to a Facebook Group's Feed in my app, using the Graph API. It works fine, except facebook keeps treating the published info as a 'link' feed item type instead of 'status' like it does when I enter the same from facebook's site. eg: string url = "https://graph.facebook.com/<id-of-group/feed?access_token=<access-token>"; string data = "message=hello"; webClient.UploadString(url, "POST", data); Now when I pull the feed items, the json that is returned has "item":"link", with "link":"http://www.facebook.com", whereas I'd expect it to be "item":"status" and no or an empty "link" property. Any ideas?

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  • How to upload a picture for an event using the Facebook Graph API?

    - by Thorarin
    I would like to know how to add a picture to an event using the Facebook Graph API. I have seen this question and tried some variations on that theme, without any success. The official documentation doesn't seem to make any mention of it. I'm using PHP for this particular project and I've looked at the PHP SDK source code, which is not helpful in any way. Requesting metadata for pictures using https://graph.facebook.com/eventid/picture?metadata=1&access_token... doesn't seem to be recognized, so no help there either. Has anyone come across some example or documentation on how to do this? (don't care about which language it is in)

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  • How i access the array of CGPoints to draw the graph?

    - by Rajendra Bhole
    Hi, I have the code in which i want to develop the graph.The code is, NSArray *coordinate = [[NSArray alloc] initWithObjects: @"42,213", @"75,173", @"108,153", @"141,133", @"174,113", @"207,73", @"240,33", nil]; CGContextSetRGBFillColor(ctx, 255, 0, 0, 1.0); CGContextSetLineWidth(ctx, 8.0); for(int intIndex = 0; intIndex < [coordinate count]; fltX1+=33, intIndex++) { CGContextMoveToPoint(ctx, fltX1+37, fltY2+18); CGPoint point = [[coordinate objectAtIndex:intIndex] CGPointValue]; CGContextAddLineToPoint(ctx, point); CGContextStrokePath(ctx); } The problem is that the function of CGContextAddLineToPoint(ctx, point); not working properly. How i drawing the line in the graph using above code????????

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  • Are there algorithms for increasing resolution of an image?

    - by David
    Are there any algorithms or tools that can increase the resolution of an image - besides just a simple zoom that makes each individual pixel in the image a little larger? I realize that such an algorithm would have to invent pixels that don't really exist in the original image, but I figured there might be some algorithm that could intelligently figure out what pixels to add to the image to increase its resolution.

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  • Flex Custom UIComponents

    - by user164142
    I have created a graph component in AS3 which extends UIComponent. I created an mxml component which is just a Label. The idea is to use the label component to show the values on the graph when you hover over points. I have tried two approaches. Create the Label component using ClassFactory inside the graph so it gets created in the graph component and addChild is called there. The problem is it is always 0 in size. Create in main mxml file and pass in to graph using a setter, the sizing is perfect but the x an y dont relate to my graph :( I suppose its similar to flex and itemrenderers, but in my case i have a graph and another component which can be changed, at the moment it is just a Label. Thanks Neil

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