Charles, what is your platform? OS, OS version, C compiler version? Anything else that you might think is needed to reproduce this?
G. On Wed, Dec 5, 2012 at 3:44 PM, Charles Novaes de Santana < [email protected]> wrote: > Just to explay why I think my problem with the "infinity" values: > > Because I tryied to debug my program and I got the following message: > > Program received signal SIGSEGV, Segmentation fault. > igraph_vector_fill (v=0xbffff6ac, e=inf) at vector.pmt:682 > 682 *ptr = e; > > As the value received by function igraph_vector_fill is "e=inf" I > suppose it was my problem. > > Best, > > Charles > > On Wed, Dec 5, 2012 at 9:40 PM, Charles Novaes de Santana > <[email protected]> wrote: > > Thank you again, Tamás. You were absolutely right about my mistake in > > printing the matrix. I did a simple cast and my matrix operations > > worked fine. > > > > But I still have problems with the "infinity" given by the > > shortest_paths function. I did the function you suggested me (to > > replace all IGRAPH_INFINITY by zeros), but I have problems in the > > calculation of the shortest paths itself, before I have the > > opportunity to replace the "inifinity" by "zero". > > > > If you don't mind, I am sending attached to this message a small > > program with the part of my code where I got the error. And an example > > of a network I am studying. Maybe it is an error in the format of my > > network and I can not understand it yet. Or maybe it is because my > > network is very sparse. > > > > Thank you very much for your attention, > > > > Best, > > > > Charles > > > > /*SOURCE CODE*/ > > > > #include<igraph.h> > > > > int main(void){ > > igraph_t g1; > > igraph_matrix_t l1; > > igraph_vs_t vertices; > > > > int i,j; > > FILE *ifile1; > > > > /*Reading the network*/ > > ifile1=fopen("./network.net", "r"); > > if (ifile1==0) {return 10;} > > igraph_read_graph_pajek(&g1, ifile1); > > fclose(ifile1); > > > > /*Initializing the matrix l1 and the vector of vertices*/ > > > > igraph_vs_all(&vertices); > > igraph_matrix_init(&l1, 0, 0); > > > > /*Calculating the shortest paths*/ > > > > igraph_shortest_paths(&g1,&l1,vertices,vertices,IGRAPH_ALL); > > > > /*Desconstructors*/ > > igraph_matrix_destroy(&l1); > > igraph_vs_destroy(&vertices); > > igraph_destroy(&g1); > > return; > > } > > > > > > igraph_matrix_destroy(&l1); > > igraph_vs_destroy(&vertices); > > igraph_destroy(&g1); > > > > > > On Wed, Dec 5, 2012 at 10:32 AM, Tamás Nepusz <[email protected]> wrote: > >>> First, I was wondering if Igraph considers IGRAPH_INFINITY as zero or > >>> as other value. > >> IGRAPH_INFINITY is infinity, period. It is there only to provide us > with a sort-of-platform-independent way to refer to infinity. > >> > >>> I am working with shortest-paths matrices and I would > >>> like the distance between two vertices that can not reach each other > >>> to be zero. > >> Well, you have to check all the cells in the matrix and if a cell is > equal to IGRAPH_INFINITY, you have to set it to zero. > >> > >>> (I tryied to do "igraph_matrix_scale(matrix,1./2)" and it gave > >>> me a zero-matrix). > >> Theoretically it should work; there is no limitation on > igraph_matrix_scale to work on integer values only. I have just tested it > on my machine and it worked for me, so I guess that the error is somewhere > else; for instance, in the way you print the values. > >> > >> Cheers, > >> -- > >> T. > >> > >> > >> _______________________________________________ > >> igraph-help mailing list > >> [email protected] > >> https://lists.nongnu.org/mailman/listinfo/igraph-help > > > > > > > > -- > > Um axé! :) > > > > -- > > Charles Novaes de Santana > > http://www.imedea.uib-csic.es/~charles > > PhD student - Global Change > > Laboratorio Internacional de Cambio Global > > Department of Global Change Research > > Instituto Mediterráneo de Estudios Avanzados(CSIC/UIB) > > Calle Miquel Marques 21, 07190 > > Esporles - Islas Baleares - España > > > > Office phone - +34 971 610 896 > > Cell phone - +34 660 207 940 > > > > -- > Um axé! :) > > -- > Charles Novaes de Santana > http://www.imedea.uib-csic.es/~charles > PhD student - Global Change > Laboratorio Internacional de Cambio Global > Department of Global Change Research > Instituto Mediterráneo de Estudios Avanzados(CSIC/UIB) > Calle Miquel Marques 21, 07190 > Esporles - Islas Baleares - España > > Office phone - +34 971 610 896 > Cell phone - +34 660 207 940 > > _______________________________________________ > igraph-help mailing list > [email protected] > https://lists.nongnu.org/mailman/listinfo/igraph-help > -- Gabor Csardi <[email protected]> MTA KFKI RMKI
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