[igraph] Using dynamics vectors to storage my graph's edges

[Christian Gonzalez]

Hello everybody,

I'm trying to use "dynamics vector" to store my graph's edges, because I 
have a lot of edges.  But the "igraph library" doesn't handle it.  there 
is some way to store my edges in the heap memory?


this is my code.

#include <igraph/igraph.h>

int
main(int argc, char* argv[])
{
  igraph_t                     graph;
  igraph_vector_t         result;
  igraph_vector_t            weights;
  igraph_real_t            w = 10;
  igraph_vector_ptr_t     result_vector;
  igraph_integer_t         from = 100;
  igraph_integer_t        to = 400;
  igraph_vector_t         edges;

  igraph_real_t             *ptr_edges;
  //igraph_real_t             *ptr_edge[18];

  /*igraph_real_t         edges_v[] = {
                                          100, 200,
                                          100, 300,
                                          200, 400,
                                          300, 600,
                                          300, 500,
                                          400, 300,
                                          500, 700,
                                          700, 600,
                                          800, 600
                                      };*/

  if ( (ptr_edges = calloc(9 * 2, sizeof(igraph_real_t))) == NULL)
  {
      /*
      ptr_edge[0] = 100; ptr_edge[1] = 200;
      ptr_edge[2] = 100; ptr_edge[3] = 300;
      ptr_edge[4] = 200; ptr_edge[5] = 400;
      ptr_edge[6] = 300; ptr_edge[7] = 600;
      ptr_edge[8] = 300; ptr_edge[9] = 500;
      ptr_edge[10] = 400; ptr_edge[11] = 300;
      ptr_edge[12] = 500; ptr_edge[13] = 700;
      ptr_edge[14] = 700; ptr_edge[15] = 600;
      ptr_edge[16] = 800; ptr_edge[17] = 600;
      */
      *(ptr_edges+0) = 100; *(ptr_edges+1) = 200;
      *(ptr_edges+2) = 100; *(ptr_edges+3) = 300;
      *(ptr_edges+4) = 200; *(ptr_edges+5) = 400;
      *(ptr_edges+6) = 300; *(ptr_edges+7) = 600;
      *(ptr_edges+8) = 300; *(ptr_edges+9) = 500;
      *(ptr_edges+10) = 400; *(ptr_edges+11) = 300;
      *(ptr_edges+12) = 500; *(ptr_edges+13) = 700;
      *(ptr_edges+14) = 700; *(ptr_edges+15) = 600;
      *(ptr_edges+16) = 800; *(ptr_edges+17) = 600;
  }

  igraph_vector_view(&edges, ptr_edges, sizeof(9 * 2, 
sizeof(igraph_real_t))/sizeof(igraph_real_t));

  igraph_create( &graph, &edges, 0, IGRAPH_DIRECTED);

  igraph_vector_init(&result, 0);

  igraph_vector_ptr_init(&result_vector, 1);

  VECTOR(result_vector)[0] = &result;

  igraph_vector_init( &weights, igraph_ecount(&graph) );

  printf("vertices: %i, lados: %i\n", (int)igraph_vcount(&graph), 
(int)igraph_ecount(&graph));

  igraph_vector_fill(&weights,  w);

  igraph_get_shortest_paths_dijkstra( &graph,
&result_vector,
                                        from,
                                        igraph_vss_1(to),
&weights,
                                        IGRAPH_OUT);


  for (int i = 0; i < igraph_vector_size(&result); i++)
  {
    printf("%ld ", (long) igraph_vector_e(&result, i));
  }

  printf("\n");

  igraph_destroy(&graph);
  igraph_vector_destroy(&result);
  igraph_vector_destroy(&weights);
  igraph_vector_ptr_destroy(&result_vector);

  return EXIT_SUCCESS;
}

this is my output:

address@hidden igraphtest]$ build/myigraph
vertices: 0, lados: 0
Error at iterators.c:709 :Cannot create iterator, invalid vertex id, 
Invalid vertex id
Abortado