Search Results

Search found 4133 results on 166 pages for 'boost graph'.

Page 25/166 | < Previous Page | 21 22 23 24 25 26 27 28 29 30 31 32  | Next Page >

  • Mixing C and C++, raw pointers and (boost) shared pointers

    - by oompahloompah
    I am working in C++ with some legacy C code. I have a data structure that (during initialisation), makes a copy of the structure pointed to a ptr passed to its initialisation pointer. Here is a simplification of what I am trying to do - hopefully, no important detail has been lost in the "simplification": /* C code */ typedef struct MyData { double * elems; unsigned int len; }; int NEW_mydata(MyData* data, unsigned int len) { // no error checking data->elems = (double *)calloc(len, sizeof(double)); return 0; } typedef struct Foo { MyData data data_; }; void InitFoo(Foo * foo, const MyData * the_data) { //alloc mem etc ... then assign the STRUCTURE foo.data_ = *thedata ; } C++ code ------------- typedef boost::shared_ptr<MyData> MyDataPtr; typedef std::map<std::string, MyDataPtr> Datamap; class FooWrapper { public: FooWrapper(const std::string& key) { MyDataPtr mdp = dmap[key]; InitFoo(&m_foo, const_cast<MyData*>((*mdp.get()))); } ~FooWrapper(); double get_element(unsigned int index ) const { return m_foo.elems[index]; } private: // non copyable, non-assignable FooWrapper(const FooWrapper&); FooWrapper& operator= (const FooWrapper&); Foo m_foo; }; int main(int argc, char *argv[]) { MyData data1, data2; Datamap dmap; NEW_mydata(&data1, 10); data1->elems[0] = static_cast<double>(22/7); NEW_mydata(&data2, 42); data2->elems[0] = static_cast<double>(13/21); boost::shared_ptr d1(&data1), d2(&data2); dmap["data1"] = d1; dmap["data2"] = d2; FooWrapper fw("data1"); //expect 22/7, get something else (random number?) double ret fw.get_element(0); } Essentially, what I want to know is this: Is there any reason why the data retrieved from the map is different from the one stored in the map?

    Read the article

  • any stl/boost functors to call operator()

    - by Voivoid
    template <typename T> struct Foo { void operator()(T& t) { t(); } }; Is there any standart or boost functor with the similar implementation? I need it to iterate over container of functors: std::for_each(beginIter, endIter, Foo<Bar>()); Or maybe there are other way to do it?

    Read the article

  • Boost::asio::endpoint::size() and resize()

    - by p00ya
    hi. I was reading the boost endpoint documentation and saw size() and resize() member funcs. the documentation says: Gets the underlying size of the endpoint in the native type. what does this size represent and where can it be used/resized ? thanks.

    Read the article

  • PHP OCI8 and Oracle 11g DRCP Connection Pooling in Pictures

    - by christopher.jones
    Here is a screen shot from a PHP OCI8 connection pooling demo that I like to run. It graphically shows how little database host memory is needed when using DRCP connection pooling with Oracle Database 11g. Migrating to DRCP can be as simple as starting the pool and changing the connection string in your PHP application. The script that generated the data for this graph was a simple "Parts" query application being run under various simulated user loads. I was running the database on a small Oracle Linux server with just 2G of memory. I used PHP OCI8 1.4. Apache is in pre-fork mode, as needed for PHP. Each graph has time on the horizontal access in arbitrary 'tick' time units. Click the image to see it full sized. Pooled connections Beginning with the top left graph, At tick time 65 I used Apache's 'ab' tool to start 100 concurrent 'users' running the application. These users connected to the database using DRCP: $c = oci_pconnect('phpdemo', 'welcome', 'myhost/orcl:pooled'); A second hundred DRCP users were added to the system at tick 80 and a final hundred users added at tick 100. At about tick 110 I stopped the test and restarted Apache. This closed all the connections. The bottom left graph shows the number of statements being executed by the database per second, with some spikes for background database activity and some variability for this small test. Each extra batch of users adds another 'step' of load to the system. Looking at the top right Server Process graph shows the database server processes doing the query work for each web user. As user load is added, the DRCP server pool increases (in green). The pool is initially at its default size 4 and quickly ramps up to about (I'm guessing) 35. At tick time 100 the pool increases to my configured maximum of 40 processes. Those 40 processes are doing the query work for all 300 web users. When I stopped the test at tick 110, the pooled processes remained open waiting for more users to connect. If I had left the test quiet for the DRCP 'inactivity_timeout' period (300 seconds by default), the pool would have shrunk back to 4 processes. Looking at the bottom right, you can see the amount of memory being consumed by the database. During the initial quiet period about 500M of memory was in use. The absolute number is just an indication of my particular DB configuration. As the number of pooled processes increases, each process needs more memory. You can see the shape of the memory graph echoes the Server Process graph above it. Each of the 300 web users will also need a few kilobytes but this is almost too small to see on the graph. Non-pooled connections Compare the DRCP case with using 'dedicated server' processes. At tick 140 I started 100 web users who did not use pooled connections: $c = oci_pconnect('phpdemo', 'welcome', 'myhost/orcl'); This connection string change is the only difference between the two tests. At ticks 155 and 165 I started two more batches of 100 simulated users each. At about tick 195 I stopped the user load but left Apache running. Apache then gradually returned to its quiescent state, killing idle httpd processes and producing the downward slope at the right of the graphs as the persistent database connection in each Apache process was closed. The Executions per Second graph on the bottom left shows the same step increases as for the earlier DRCP case. The database is handling this load. But look at the number of Server processes on the top right graph. There is now a one-to-one correspondence between Apache/PHP processes and DB server processes. Each PHP processes has one DB server processes dedicated to it. Hence the term 'dedicated server'. The memory required on the database is proportional to all those database server processes started. Almost all my system's memory was consumed. I doubt it would have coped with any more user load. Summary Oracle Database 11g DRCP connection pooling significantly reduces database host memory requirements allow more system memory to be allocated for the SGA and allowing the system to scale to handled thousands of concurrent PHP users. Even for small systems, using DRCP allows more web users to be active. More information about PHP and DRCP can be found in the PHP Scalability and High Availability chapter of The Underground PHP and Oracle Manual.

    Read the article

  • How does I/O work for large graph databases?

    - by tjb1982
    I should preface this by saying that I'm mostly a front end web developer, trained as a musician, but over the past few years I've been getting more and more into computer science. So one idea I have as a fun toy project to learn about data structures and C programming was to design and implement my own very simple database that would manage an adjacency list of posts. I don't want SQL (maybe I'll do my own query language? I'm just having fun). It should support ACID. It should be capable of storing 1TB let's say. So with that, I was trying to think of how a database even stores data, without regard to data structures necessarily. I'm working on linux, and I've read that in that world "everything is a file," including hardware (like /dev/*), so I think that that obviously has to apply to a database, too, and it clearly does--whether it's MySQL or PostgreSQL or Neo4j, the database itself is a collection of files you can see in the filesystem. That said, there would come a point in scale where loading the entire database into primary memory just wouldn't work, so it doesn't make sense to design it with that mindset (I assume). However, reading from secondary memory would be much slower and regardless some portion of the database has to be in primary memory in order for you to be able to do anything with it. I read this post: Why use a database instead of just saving your data to disk? And I found it difficult to understand how other databases, like SQLite or Neo4j, read and write from secondary memory and are still very fast (faster, it would seem, than simply writing files to the filesystem as the above question suggests). It seems the key is indexing. But even indexes need to be stored in secondary memory. They are inherently smaller than the database itself, but indexes in a very large database might be prohibitively large, too. So my question is how is I/O generally done with large databases like the one I described above that would be at least 1TB storing a big adjacency list? If indexing is more or less the answer, how exactly does indexing work--what data structures should be involved?

    Read the article

  • Facebook - Publish Checkins using Graph API

    - by Zany
    I'm trying to publish Checkin using Facebook Graph API. I've gone through Facebook API documentation (checkins) and also have the publish_checkins permission. However, my checkin is not getting published. May I know is there anything wrong or am I missing anything else? Thank you for your time :) fbmain.php $user = $facebook->getUser(); $access_token = $facebook->getAccessToken(); // Session based API call if ($user) { try { $me = $facebook->api('/me'); if($me) { $_SESSION['fbID'] = $me['id']; $uid = $me['id']; } } catch (FacebookApiException $e) { error_log($e); } } else { echo "<script type='text/javascript'>top.location.href='$loginUrl';</script>"; exit; } $loginUrl = $facebook->getLoginUrl( array( 'redirect_uri' => $redirect_url, 'scope' => status_update, publish_stream, publish_checkins, user_checkins, user_location, user_status' ) ); main.php (Updated: 18/6/2012 11.12pm) <?php include_once "fbmain.php"; if (!isset($_POST['latitude']) && !isset($_POST['longitude'])) { ?> <html> <head> //ajax POST of latitude and longitude </head> <body> <script type="text/javascript"> window.fbAsyncInit = function() { FB.init({ appId: '<?php echo $facebook->getAppID() ?>', cookie: true, xfbml: true, oauth: true, frictionlessRequests: true }); FB.Canvas.setAutoGrow(); }; (function() { var e = document.createElement('script'); e.async = true; e.src = document.location.protocol + '//connect.facebook.net/en_US/all.js'; document.getElementById('fb-root').appendChild(e); }()); </script> ... <input type="button" value="Check In!" onclick="checkin(<?=$facebook?>);"/></span> </body> </html> <?php } else { print_r($_POST['latitude']); print_r($_POST['longitude']); ?> <script type="text/javascript"> // not using latitude and longitude to test function checkin($fb) { try { $tryCatch = $facebook->api('/'.$_SESSION['fbID'].'/checkins', 'POST', array( 'access_token' => $fb->getAccessToken(), //corrected 'place' => '165122993538708', 'message' =>'I went to placename today', 'coordinates' => json_encode(array( 'latitude' => '1.3019399200902', 'longitude' => '103.84067653695' )) )); } catch(FacebookApiException $e) { $tryCatch=$e->getMessage(); } return $tryCatch; } </script> <?php } ?>

    Read the article

  • Merging .net object graph

    - by Tiju John
    Hi guys, has anyone come across any scenario wherein you needed to merge one object with another object of same type, merging the complete object graph. for e.g. If i have a person object and one person object is having first name and other the last name, some way to merge both the objects into a single object. public class Person { public Int32 Id { get; set; } public string FirstName { get; set; } public string LastName { get; set; } } public class MyClass { //both instances refer to the same person, probably coming from different sources Person obj1 = new Person(); obj1.Id=1; obj1.FirstName = "Tiju"; Person obj2 = new Person(); ojb2.Id=1; obj2.LastName = "John"; //some way of merging both the object obj1.MergeObject(obj2); //?? //obj1.Id // = 1 //obj1.FirstName // = "Tiju" //obj1.LastName // = "John" } I had come across such type of requirement and I wrote an extension method to do the same. public static class ExtensionMethods { private const string Key = "Id"; public static IList MergeList(this IList source, IList target) { Dictionary itemData = new Dictionary(); //fill the dictionary for existing list string temp = null; foreach (object item in source) { temp = GetKeyOfRecord(item); if (!String.IsNullOrEmpty(temp)) itemData[temp] = item; } //if the same id exists, merge the object, otherwise add to the existing list. foreach (object item in target) { temp = GetKeyOfRecord(item); if (!String.IsNullOrEmpty(temp) && itemData.ContainsKey(temp)) itemData[temp].MergeObject(item); else source.Add(item); } return source; } private static string GetKeyOfRecord(object o) { string keyValue = null; Type pointType = o.GetType(); if (pointType != null) foreach (PropertyInfo propertyItem in pointType.GetProperties()) { if (propertyItem.Name == Key) { keyValue = (string)propertyItem.GetValue(o, null); } } return keyValue; } public static object MergeObject(this object source, object target) { if (source != null && target != null) { Type typeSource = source.GetType(); Type typeTarget = target.GetType(); //if both types are same, try to merge if (typeSource != null && typeTarget != null && typeSource.FullName == typeTarget.FullName) if (typeSource.IsClass && !typeSource.Namespace.Equals("System", StringComparison.InvariantCulture)) { PropertyInfo[] propertyList = typeSource.GetProperties(); for (int index = 0; index < propertyList.Length; index++) { Type tempPropertySourceValueType = null; object tempPropertySourceValue = null; Type tempPropertyTargetValueType = null; object tempPropertyTargetValue = null; //get rid of indexers if (propertyList[index].GetIndexParameters().Length == 0) { tempPropertySourceValue = propertyList[index].GetValue(source, null); tempPropertyTargetValue = propertyList[index].GetValue(target, null); } if (tempPropertySourceValue != null) tempPropertySourceValueType = tempPropertySourceValue.GetType(); if (tempPropertyTargetValue != null) tempPropertyTargetValueType = tempPropertyTargetValue.GetType(); //if the property is a list IList ilistSource = tempPropertySourceValue as IList; IList ilistTarget = tempPropertyTargetValue as IList; if (ilistSource != null || ilistTarget != null) { if (ilistSource != null) ilistSource.MergeList(ilistTarget); else propertyList[index].SetValue(source, ilistTarget, null); } //if the property is a Dto else if (tempPropertySourceValue != null || tempPropertyTargetValue != null) { if (tempPropertySourceValue != null) tempPropertySourceValue.MergeObject(tempPropertyTargetValue); else propertyList[index].SetValue(source, tempPropertyTargetValue, null); } } } } return source; } } However, this works when the source property is null, if target has it, it will copy that to source. IT can still be improved to merge when inconsistencies are there e.g. if FirstName="Tiju" and FirstName="John" Any commments appreciated. Thanks TJ

    Read the article

  • Scala: Recursively building all pathes in a graph?

    - by DarqMoth
    Trying to build all existing paths for an udirected graph defined as a map of edges using the following algorithm: Start: with a given vertice A Find an edge (X.A, X.B) or (X.B, X.A), add this edge to path Find all edges Ys fpr which either (Y.C, Y.B) or (Y.B, Y.C) is true For each Ys: A=B, goto Start Providing edges are defined as the following map, where keys are tuples consisting of two vertices: val edges = Map( ("n1", "n2") -> "n1n2", ("n1", "n3") -> "n1n3", ("n3", "n4") -> "n3n4", ("n5", "n1") -> "n5n1", ("n5", "n4") -> "n5n4") As an output I need to get a list of ALL pathes where each path is a list of adjecent edges like this: val allPaths = List( List(("n1", "n2") -> "n1n2"), List(("n1", "n3") -> "n1n3", ("n3", "n4") -> "n3n4"), List(("n5", "n1") -> "n5n1"), List(("n5", "n4") -> "n5n4"), List(("n2", "n1") -> "n1n2", ("n1", "n3") -> "n1n3", ("n3", "n4") -> "n3n4", ("n5", "n4") -> "n5n4")) //... //... more pathes to go } Note: Edge XY = (x,y) - "xy" and YX = (y,x) - "yx" exist as one instance only, either as XY or YX So far I have managed to implement code that duplicates edges in the path, which is wrong and I can not find the error: object Graph2 { type Vertice = String type Edge = ((String, String), String) type Path = List[((String, String), String)] val edges = Map( //(("v1", "v2") , "v1v2"), (("v1", "v3") , "v1v3"), (("v3", "v4") , "v3v4") //(("v5", "v1") , "v5v1"), //(("v5", "v4") , "v5v4") ) def main(args: Array[String]): Unit = { val processedVerticies: Map[Vertice, Vertice] = Map() val processedEdges: Map[(Vertice, Vertice), (Vertice, Vertice)] = Map() val path: Path = List() println(buildPath(path, "v1", processedVerticies, processedEdges)) } /** * Builds path from connected by edges vertices starting from given vertice * Input: map of edges * Output: list of connected edges like: List(("n1", "n2") -> "n1n2"), List(("n1", "n3") -> "n1n3", ("n3", "n4") -> "n3n4"), List(("n5", "n1") -> "n5n1"), List(("n5", "n4") -> "n5n4"), List(("n2", "n1") -> "n1n2", ("n1", "n3") -> "n1n3", ("n3", "n4") -> "n3n4", ("n5", "n4") -> "n5n4")) */ def buildPath(path: Path, vertice: Vertice, processedVerticies: Map[Vertice, Vertice], processedEdges: Map[(Vertice, Vertice), (Vertice, Vertice)]): List[Path] = { println("V: " + vertice + " VM: " + processedVerticies + " EM: " + processedEdges) if (!processedVerticies.contains(vertice)) { val edges = children(vertice) println("Edges: " + edges) val x = edges.map(edge => { if (!processedEdges.contains(edge._1)) { addToPath(vertice, processedVerticies.++(Map(vertice -> vertice)), processedEdges, path, edge) } else { println("ALready have edge: "+edge+" Return path:"+path) path } }) val y = x.toList y } else { List(path) } } def addToPath( vertice: Vertice, processedVerticies: Map[Vertice, Vertice], processedEdges: Map[(Vertice, Vertice), (Vertice, Vertice)], path: Path, edge: Edge): Path = { val newPath: Path = path ::: List(edge) val key = edge._1 val nextVertice = neighbor(vertice, key) val x = buildPath (newPath, nextVertice, processedVerticies, processedEdges ++ (Map((vertice, nextVertice) -> (vertice, nextVertice))) ).flatten // need define buidPath type x } def children(vertice: Vertice) = { edges.filter(p => (p._1)._1 == vertice || (p._1)._2 == vertice) } def containsPair(x: (Vertice, Vertice), m: Map[(Vertice, Vertice), (Vertice, Vertice)]): Boolean = { m.contains((x._1, x._2)) || m.contains((x._2, x._1)) } def neighbor(vertice: String, key: (String, String)): String = key match { case (`vertice`, x) => x case (x, `vertice`) => x } } Running this results in: List(List(((v1,v3),v1v3), ((v1,v3),v1v3), ((v3,v4),v3v4))) Why is that?

    Read the article

  • How to pass user-defined structs using boost mpi

    - by lava
    I am trying to send a user-defined structure named ABC using boost::mpi::send () call. The given struct contains a vector "data" whose size is determined at runtime. Objects of struct ABC are sent by master to slaves. But the slaves need to know the size of vector "data" so that the sufficient buffer is available on the slave to receive this data. I can work around it by sending the size first and initialize sufficient buffer on the slave before receiving the objects of struct ABC. But that defeats the whole purpose of using STL containers. Does anyone know of a better way to do handle this ? Any suggestions are greatly appreciated. Here is a sample code that describes the intent of my program. This code fails at runtime due to above mentioned reason. struct ABC { double cur_stock_price; double strike_price; double risk_free_rate; double option_price; std::vector <char> data; }; namespace boost { namespace serialization { template<class Archive> void serialize (Archive &ar, struct ABC &abc, unsigned int version) { ar & abc.cur_stock_price; ar & abc.strike_price; ar & abc.risk_free_rate; ar & abc.option_price; ar & bopr.data; } } } BOOST_IS_MPI_DATATYPE (ABC); int main(int argc, char* argv[]) { mpi::environment env (argc, argv); mpi::communicator world; if (world.rank () == 0) { ABC abc_obj; abc.cur_stock_price = 1.0; abc.strike_price = 5.0; abc.risk_free_rate = 2.5; abc.option_price = 3.0; abc_obj.data.push_back ('a'); abc_obj.data.push_back ('b'); world.send ( 1, ANY_TAG, abc_obj;); std::cout << "Rank 0 OK!" << std::endl; } else if (world.rank () == 1) { ABC abc_obj; // Fails here because abc_obj is not big enough world.recv (0,ANY_TAG, abc_obj;); std::cout << "Rank 1 OK!" << std::endl; for (int i = 0; i < abc_obj;.data.size(); i++) std::cout << i << "=" << abc_obj.data[i] << std::endl; } MPI_Finalize(); return 0; }

    Read the article

  • How to implement tokenizer.rbegin() and rend() for boost::tokenizer ?

    - by Chan
    Hello everyone, I'm playing around with boost::tokenizer however I realize that it does not support rbegin() and rend(). I would like to ask how can I add these two functions to the existing class? This is from the boost site: #include <iostream> #include <string> #include <boost/tokenizer.hpp> using namespace std; using namespace boost; int main() { string str( "12/12/1986" ); typedef boost::tokenizer<boost::char_separator<char>> tokenizer; boost::char_separator<char> sep( "/" ); tokenizer tokens( str, sep ); cout << *tokens.begin() << endl; // cout << *tokens.rbegin() << endl; How could I implement this? return 0; }

    Read the article

  • boost spirit semantic action parameters

    - by lurscher
    Hi, in this article about boost spirit semantic actions it is mentioned that There are actually 2 more arguments being passed: the parser context and a reference to a boolean ‘hit’ parameter. The parser context is meaningful only if the semantic action is attached somewhere to the right hand side of a rule. We will see more information about this shortly. The boolean value can be set to false inside the semantic action invalidates the match in retrospective, making the parser fail. All fine, but i've been trying to find an example passing a function object as semantic action that uses the other parameters (parser context and hit boolean) but i haven't found any. I would love to see an example using regular functions or function objects, as i barely can grok the phoenix voodoo

    Read the article

  • Pass by reference in Boost::Python

    - by Fabzter
    Hi everybody. Consider something like: struct Parameter { int a; Parameter(){a = 0} void setA(int newA){a = newA;} }; struct MyClass { void changeParameter(Parameter &p){ p.setA(-1);} }; Well, let's fast forward, and imagine I already wrapped those classes, exposing everything to python, and imagine also I instantiate an object of Parameter in the C++ code, which I pass to the python script, and that python script uses a MyClass object to modify the instance of Parameter I created at the beginning in the C++ code. After that code executes, in C++ Parameter instance is unchanged!!! This means it was passed by value (or something alike :S), not by reference. But I thought I declared it to be passed by reference... I can't seem to find Boost::Python documentation about passing by reference (although there seems to be enough doc about returning by reference...). Can anyone give some hint or pointer please?

    Read the article

  • Boost bind function

    - by Gokul
    Hi, I have a abstract base class A and a set of 10 derived classes. The infix operator is overloaded in all of the derived classes class A{ void printNode( std::ostream& os ) { this->printNode_p(); } void printNode_p( std::ostream& os ) { os << (*this); } }; There is a container which stores the base class pointers. I want to use boost::bind function to call the overloaded infix operator in each of its derived class. I have written like this std::vector<A*> m_args .... std::ostream os; for_each( m_args.begin(), m_args.end(), bind(&A::printNode, _1, os) ); What is the problem with this code? Thanks, Gokul.

    Read the article

  • Boost.Program_Options not working with short options

    - by inajamaica
    I have the following options_description: po::options_description config("Configuration File or Command Line"); config.add_options() ("run-time,t", po::value(&runTime_)-default_value(1440.0), "set max simulation duration") ("starting-iteration,i", po::value(&startingIteration_)-default_value(1), "set starting simulation iteration") ("repetitions,r", po::value(&repetitions_)-default_value(100), "set number of iterations") ... ; As you can see the three shown have a long,short names employed. The long versions all work. However, none of the short ones do, and each time I try a -t 12345.0 or a -i 12345, etc., I get the following from Program_Options: std::logic_error: in option 'starting-iteration': invalid option value I'm using Boost 1.42 on Win32. Any thoughts on what might be going on here? Thanks!

    Read the article

  • Using STL/Boost to initialize a hard-coded set<vector<int> >

    - by Hooked
    Like this question already asked, I'd like to initialize a container using STL where the elements are hard-coded in the cleanest manner possible. In this case, the elements are a doubly nested container: set<vector<int> > A; And I'd like (for example) to put the following values in: A = [[0,0,1],[0,1,0],[1,0,0],[0,0,0]]; C++0x fine, using g++ 4.4.1. STL is preferable as I don't use Boost for any other parts of the code (though I wouldn't mind an example with it!).

    Read the article

  • pushing back an boost::ptr_vector<...>::iterator in another boost::ptr_vector?

    - by Ethan Nash
    Hi all, I have the following code (just typed it in here, might have typos or stuff): typedef boost::ptr_vector<SomeClass> tvec; tvec v; // ... fill v ... tvec vsnap; for(tvec::iterator it = v.begin(); it != v.end(); ++it) { if((*v).anyCondition) vsnap.push_back( it ); // (*it) or &(*it) doesn't work } My problem is now that i cant push_back an iterator in any way, I just don't get the pointer out of the iterator. Is there an easy way i didnt see, or are boosts ptr_vector the false choice for this case? Thanks in advance.

    Read the article

  • Boost python module building

    - by Ockonal
    Hello, I'm using boost.python and I need in building some module for it. I have an some_module.cpp file in project. How can I build it correctly to the shared library for using it with python in future? When I learned it, I had only 1 file and I built it with command: gcc -shared -Wl,-soname,hello.so -o hello.so test.cpp -I /usr/include/python2.6/ -lboost_python And I don't know how to configure it in whole project. I'm using Eclipse and Code::Blocks IDEs.

    Read the article

  • Passing Boost uBLAS matrices to OpenGL shader

    - by AJM
    I'm writing an OpenGL program where I compute my own matrices and pass them to shaders. I want to use Boost's uBLAS library for the matrices, but I have little idea how to get a uBLAS matrix into OpenGL's shader uniform functions. matrix<GLfloat, column_major> projection(4, 4); // Fill matrix ... GLuint projectionU = glGetUniformLocation(shaderProgram, "projection"); glUniformMatrix4fv(projectionU, 1, 0, (GLfloat *)... Um ...); Trying to cast the matrix to a GLfloat pointer causes an invalid cast error on compile.

    Read the article

  • Using boost::asio::async_read with stdin?

    - by yeus
    hi poeple.. short question: I have a realtime-simulation which is running as a backround process and is connected with pipes to the calling pogramm. I want to send commands to that process using stdin to get certain information from it via stdout. Now because it is a real-time process, it has to be a non blocking input. Is boost::asio::async_read in conjunction with iostream::cin a good idea for this task? how would I use that function if it is feasible? Any more suggestions?

    Read the article

  • Sample the deltas between values using boost::accumulators

    - by Checkers
    I have a data set with N integers (say, 13, 16, 17, 20) where each next sample is incremented by some value (3, 1, 3 in this case) and I want to use boost::accumulators::accumulator_set to find various statistics of the second sequence. I want to be able to do something like this: accumulator_set< double, features< tag::mean > > acc; ... acc(13); acc(16); acc(17); acc(20); ...BUT sampling the differences instead of the actual values. How can I do that with accumulator_set without keeping track of the last value manually?

    Read the article

  • basic boost date_time input format question

    - by Chris H
    I've got a pointer to a string, (char *) as input. The date/time looks like this: Sat, 10 Apr 2010 19:30:00 I'm only interested in the date, not the time. I created an "input_facet" with the format I want: boost::date_time::date_input_facet inFmt("%a %d %b %Y"); but I'm not sure what to do with it. Ultimately I'd like to create a date object from the string. I'm pretty sure I'm on the right track with that input facet and format, but I have no idea how to use it. Thanks.

    Read the article

  • Boost signals and passing class method

    - by Ockonal
    Hello, I've defined some signal: typedef boost::signals2::signal<void (int temp)> SomeSig; typedef SomeSig::slot_type SomeSigType; I have some class: class SomeClass { SomeClass() { SomeSig.connect(&SomeClass::doMethod); } void doMethod(const SomeSig &slot); }; And got a lot of errors: error: ‘BOOST_PP_ENUM_SHIFTED_PARAMS_M’ was not declared in this scope error: ‘T’ was not declared in this scope error: a function call cannot appear in a constant-expression error: a function call cannot appear in a constant-expression error: template argument 1 is invalid error: ‘BOOST_SIGNALS2_MISC_STATEMENT’ has not been declared error: expected identifier before ‘~’ token error: expected ‘)’ before ‘~’ token error: expected ‘;’ before ‘~’ token

    Read the article

  • unique_ptr boost equivalent?

    - by wowus
    Is there some equivalent class for C++1x's std::unique_ptr in the boost libraries? The behavior I'm looking for is being able to have an exception-safe factory function, like so... std::unique_ptr<Base> create_base() { return std::unique_ptr<Base>(new Derived); } void some_other_function() { std::unique_ptr<Base> b = create_base(); // Do some stuff with b that may or may not throw an exception... // Now b is destructed automagically. }

    Read the article

< Previous Page | 21 22 23 24 25 26 27 28 29 30 31 32  | Next Page >