March 2003 - Boost-users - lists.preview.boost.org

filling in vertex_name_t property for adjacency_list
by Jack Rabbit 13 Mar '03

13 Mar '03

Hi, I'm trying to create a graph that has a name for each vertex. Below is what I've come up with so far. I really don't know what's wrong with it. Can any of you help me out? I'm using boost 1.29.0 with Visual Studio6.0sp5 on win2k. I'm getting some errors on the line that's supposed to get the property map. Then a whole bunch of others because in the end 'name' has the wrong type. kind regards, Dieter Vrancken // create some vertex names typedef std::set<std::string> StringSet; StringSet v_names; std::string names[] = { "v1", "v2", "v3" }; v_names.insert(names, names + sizeof(names)/sizeof(names[0])); // declare the graph typedef boost::adjacency_list<boost::setS, boost::vecS, boost::directedS, boost::vertex_name_t, boost::no_property, boost::graph_name_t, boost::setS> Graph; Graph g(v_names.size()); // get the property map for the vertex names boost::property_map<Graph, boost::vertex_name_t>::type name = boost::get(boost::vertex_name, g); // fill in the names StringSet::const_iterator ss_it = v_names.begin(), ss_end = v_names.end(); int i = 0; for(; ss_it!=ss_end; ++ss_it, ++i) boost::put(name, i, *ss_it);

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Efficient implementation of associative_property_map
by Martin Okrslar 12 Mar '03

12 Mar '03

Dear Boost users, for an application in computational biology I am intendig to use the BGL to compute strongly connected components of a graph with about 600.000 nodes. In the BGL book on page 103 it is mentioned, that "The choice to use std::map to implement the property map is rather inefficient in this case...". Since my graph is large I'm a bit worried about this statement. Could anybody of you please give me a hint, what other datastructure I might use here, to make it efficient? all the best Martin -- ----------------------------------------------------------------------------- Martin Okrslar MPI for Molecular Genetics phone: ++ 49 + 30 / 8413-1166 Computational Molecular Biology Fax: ++ 49 + 30 / 8413-1152 Ihnestrasse 73 email: okrslar(a)molgen.mpg.de D-14195 Berlin URL: http://cmb.molgen.mpg.de -----------------------------------------------------------------------------

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adjacency_matrix
by agiatojon 12 Mar '03

12 Mar '03

Hello all, I'm new to the list and to Boost in general and am trying to use an adjacency_matrix in order to plot coordinates (hopefully that is a good use for it). I just started trying to learn it and have entered the sample program from page 237 into my compiler (VS.NET) Below is the program I have entered. I am getting errors in that print_vertices, print_edges, and print_graph are undefined and are not members of boost. Any help apprechiated! Thanks. /** * adjaMatri.cpp * Nov 7th, 2002 * Boost Graph Library, pg. 237 */ #include <iostream> using std::cout; using std::cin; using std::endl; #include <boost/graph/adjacency_matrix.hpp> using namespace boost; int main() { enum { A, B, C, D, E, F, N }; const char *name = "ABCDEF"; typedef boost::adjacency_matrix<boost::undirectedS> UGraph; UGraph ug(N); add_edge(B, C, ug); add_edge(B, F, ug); add_edge(C, A, ug); add_edge(D, E, ug); add_edge(F, A, ug); cout << "vertex set: "; boost::print_vertices(ug, name); cout << endl; cout << "edge_set: "; boost::print_edges(ug, name); cout << endl; cout << "incident edges: "; boost::print_graph(ug, name); cout << endl; cout << "Press enter to exit..."; cin.get(); return EXIT_SUCCESS; } Jon Agiato JonAgiato(a)nyc.rr.com

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BGL: getting components of graphs with properties
by Martin Okrslar 12 Mar '03

12 Mar '03

Dear Group, when computing the connected components of a BGL graph one has to create a vector that holds the component integer assigned to each vertex (See http://www.boost.org/libs/graph/example/connected_components.cpp and http://www.boost.org/libs/graph/doc/connected_components.html) OK, that works very well. But how can I get the component number of each vertex? If my graph has internal properties, I can not simply access the vector with an iterator on the graph vertices: component[*vi]; //doesn't work! This doesn't work, because the vertices (to be specific: the vertex desriptors) of the graph aren't integers if the graph has internal properties. Any idea how to get the component of each vertex? all the best Martin -- ----------------------------------------------------------------------------- Martin Okrslar MPI for Molecular Genetics phone: ++ 49 + 30 / 8413-1166 Computational Molecular Biology Fax: ++ 49 + 30 / 8413-1152 Ihnestrasse 73 email: okrslar(a)molgen.mpg.de D-14195 Berlin URL: http://cmb.molgen.mpg.de -----------------------------------------------------------------------------

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[V2] Problems with stage rule
by klapshin 12 Mar '03

12 Mar '03

Hi, I am having few problems on CygWin with latest boost CVS snapshot. I am building project with a number of dlls, and I need a way to run program easily. I tried hardcode-dll-paths=true, but it does not seem to work on CygWin, so I decided to use stage rule to copy all binaries in top/bin folder. First problem was that CP variable is empty and copying of the dlls failed. I worked around this one with bjam -sCP=cp. BTW, was not it supposed to be relinked rather then copied? Next problem was with exe file. Stage failed with following errors: ----------------- /cygdrive/c/work/boost1/tools/build/new/stage.jam:97: in object(stage-exe-gener tor)(a)1.run *** argument error * rule object(file-target)(a)174.depends ( d + ) * called with: ( ) * missing argument d /cygdrive/c/work/boost1/tools/build/new/virtual-target.jam:86:see definition of rule 'object(file-target)(a)174.depends' being called /cygdrive/c/work/boost1/tools/build/new/generators.jam:638: in try-one-generato /cygdrive/c/work/boost1/tools/build/new/generators.jam:885: in construct-withou -caching /cygdrive/c/work/boost1/tools/build/new/generators.jam:937: in generators.const uct /cygdrive/c/work/boost1/tools/build/new/stage.jam:56: in construct /cygdrive/c/work/boost1/tools/build/new/targets.jam:604: in object(stage-target class)(a)3.generate /cygdrive/c/work/boost1/tools/build/new/targets.jam:386: in generate-really /cygdrive/c/work/boost1/tools/build/new/targets.jam:363: in object(main-target) 3.generate /cygdrive/c/work/boost1/tools/build/new/targets.jam:182: in object(project-targ t)(a)1.generate /cygdrive/c/work/boost1/tools/build/new/build-system.jam:140: in load /cygdrive/c/work/boost1/tools/build/new/modules.jam:171: in import /cygdrive/c/work/boost1/tools/build/new/bootstrap.jam:41: in boost-build /cygdrive/c/work/pricing/boost-build.jam:13: in module scope ------------------ One more thing. Suppose I want to install all dlls to bin subfolder of project root. I tried to define path-constant in project-root, and then in one of subprojects apply stage on target and supply path from that path-constant. I end up with dll being copied into bin subfolder of subproject, rather then root. Is it expected behavior? My workaround was to put all stage rules in root Jamfile. - Kirill

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BOOST_PP_NOT documentation
by Staggs Mark - mstagg 11 Mar '03

11 Mar '03

This is a _very_ minor thing, but I noticed in the documentation for BOOST_PP_NOT the following line: If x is non-zero, this macro expands to 1. Otherwise, it expands to 0. Should read: If x is zero, this macro expands to 1. Otherwise, it expands to 0. URL: http://www.boost.org/libs/preprocessor/doc/ref/not.html ---- Mark Staggs Acxiom Corp. ********************************************************************* The information contained in this communication is confidential, is intended only for the use of the recipient named above, and may be legally privileged. If the reader of this message is not the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, please re-send this communication to the sender and delete the original message or any copy of it from your computer system. Thank You.

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boost::thread not started
by justin_michel 11 Mar '03

11 Mar '03

Platform : Windows XP, Pentium 4, Visual C++ 6 sp5 I've traced down my problem with starting a thread from a DLL called from Java JNI. If you look at the source code thread.cpp in boost, you can see that a condition variable is used block the creating thread until the new thread function is started. Basically, what I am seeing is that if you wait on this condition variable, then the thread will never start. If I remove the call to param.wait() at the bottom of the constructor then everything works fine. I can't think of a logical explanation, but it's very repeatable. I was also able to recreate this problem using the latest source from CVS. The simple solution would be to remove the condition variable from thread_param code entirely. This would simplify everything, and I don't really see the value anyway. All that is currently guaranteed is that thread_proxy will be called before the boost::thread() constructor is finished. But it doesn't guarantee that threadfunc() will be called before the constructor is finished. Thanks, Justin Michel OCI

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uBLAS: Can I make my vector<...> derived class 'copy constructible' ?
by speedsnaii 11 Mar '03

11 Mar '03

Hi Joerg, or anyone who can help! As I am still on my spline templates, I came on to the following beast: template<class T> struct index_vector : public vector<std::pair<T, vector<ublas::vector<T>::size_type> > > {}; This should be an index vector that relates to a double (first) a vector of indices (second) which happens to be different for each 'first'. So far so easy. I can say: index_vector<double> IY; IY.resize(5); IY[0].first = 3.14; IY[0].second.reset(vector<double>(3)); IY[0].second[2] = 1; But I cannot: index_vector<double> IZ(IY); or index_vector<double> IZ; IZ = IY; or IZ.reset(IY); This compiles, but gives me runtime assertions because of size mismatches. I think my derived class is not 'copy constructible' and 'assignable'. Is there a simple way to fix this? (I am not even sure whether this is a uBLAS matter. So please simple tell me, and I will try to learn the missing parts.) Thank you, Roland

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How to get extents of multi_array dimensions
by Neil Mackie 11 Mar '03

11 Mar '03

I am using multi-array for the first time, without problems. Now I want to pass the multi_array around and the users of it need to find out what the maximum array indexes are in each dimension. But I do not know how to obtain them from the object. I have read the documentation and the header file but if there are any clues there I have missed them. I have also searched the archives of this list for relevant posts. Is there a call on multi_array to return the array bounds and if so how do you specify which dimension you are requesting the bounds of? Does anyone have an example they could post? Regards, Neil (J Mackie).

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index(*vi) in the BGL quick tour?
by Jack Rabbit 11 Mar '03

11 Mar '03

Hi, My IDE is VC++6.0. I'm on win2k, using boost 1.29.0. I'm trying to get the quick tour (BOOST_HOME/libs/graph/doc/quick_tour.html) of the graph library to compile, but am experiencing a problem. In the example on how to invoke Dijkstra's algorithm, it seems we're calling a function index(*vi). I'm guessing it's supposed to get the node number for the node at vertex_iterator vi. The problem is that my compiler can't find the function ('index' : undeclared identifier). Doing a manual 'search in files' doesn't reveal any legible candidates either. Is this an error in the docs or am I missing something bigger here? kind regards, Dieter Vrancken

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