Re: BGL: VC++ problem in handling moderately large graph

From: lums_at_[hidden]
Date: 2001-03-12 08:44:45

I assume you are getting a run-time error of some kind?

Are you running out of memory?

Back of my envelope says:

Taking a quick look without trying to compile or to run the code, it 
looks like you are inserting 17 edges per node in a graph of size 
256k.  This is about 4.25M edges, each of which takes a double at 8 
bytes for 36MB.  Adding 8 more bytes for representing the edge on the 
in_edges and out_edges brings us up to 72MB.  

With some more overhead here or there, this could get somewhat 
larger.  This is still what *I* would call a moderately sized graph, 
however, if you are using a PC (implied by VC++), this might be 
pushing it.

--- In boost_at_y..., hankel_o_fung_at_y... wrote:
> VC++ 6.0 SP5 seems unable to handle a moderately large graph.
> Is it my mistake or VC++'s? Any workaround?
> 
> Hankel
> 
> #include <boost/graph/adjacency_list.hpp>
> #include <iostream>
> using namespace std;
> using namespace boost;
> 
> typedef adjacency_list< listS, vecS, undirectedS,
>   no_property, property<edge_weight_t, double> > Graph;
> 
> int const N = 512;
> int index(int i, int j) { return i*N + j; }
> 
> int main()
> {
>   Graph G(N*N);
> 
>   for (int i=0; i<N-1; ++i)
>   {
>     cout << i << flush;
>     for (int j=0; j<N; ++j)
>     {
>       int begin = (j-8   < 0  ?  0 : j-8);
>       int end   = (j+8+1 > N  ?  N : j+8+1);
>       for (int k=begin; k<end; ++k)
>         put(edge_weight, G, add_edge(index(i,j), index(i+1,k), 
> G).first, 1.0);
>         // this is simplified -- in my original program G hasn't a 
> regular structure
>     }
>     cout << endl;
>   }
> 
>   return 0;
> }