Re: [Boost-users] graph cut compilation error

8 Sep 2009

      On Tue, Sep 8, 2009 at 1:17 PM, Jeremiah Willcock wrote:
...
On Tue, 8 Sep 2009, David Doria wrote:
I made a super simple example: A graph with 2 nodes and an edge between
...
them. On trying to call kolmogorov_max_flow, I am getting:
error: cannot convert 'boost::detail::error_property_not_found' to 'long
int' in initialization
You are missing the edge weights and other property maps described in the
documentation for kolmogorov_max_flow; you can supply them either as
parameters to the kolmogorov_max_flow function or as particular property
maps in your graph.  You can add properties as template parameters to the
adjacency_list class (see the documentation for how to do that), or use
external properties.  Once you have properties, you can use add_edge(source,
target, prop, g) to add edges with properties.
-- Jeremiah Willcock
__
Jeremiah,

Thanks for the response. I am very new to boost, so I am not quite getting
the Property Map idea.
It seems like you can just provide a whole list of template arguments that
are of type property<> to the adjacency_list object. It the kolmogorov
example (
http://www.boost.org/doc/libs/1_39_0/libs/graph/doc/kolmogorov_max_flow.html)
, it looks like the only property that is needed is edge_capacity, so I
defined EdgeCapacityProperty (it was actually quite a complicated property,
depending on edge_reverse as well as edge_residual_capacity).  However, I am
still getting "conversion from error_property_not_found to
EdgeCapacityProperty requested" when I try to call the maxflow function. Is
this getting closer?

I guess I am following the property<> stuff, but not the property_map<>
idea? Here is the latest attempt:

#include <iostream>                  // for std::cout
#include 
#include 

using namespace boost;

typedef adjacency_list_traits Traits;

typedef property
EdgeReverseProperty;
typedef property
EdgeResidualCapacityProperty;
typedef property
EdgeCapacityProperty;

typedef adjacency_list
Graph; //simple

int main(int,char*[])
{
   // declare a graph object
    Graph g(2); //a graph with 2 vertices

    //add an edge between node 0 and node 1 with weight (capacity) 2.3
    EdgeCapacityProperty e = 2.3;
    add_edge(0, 1, e, g);

    //find min cut

    Traits::vertex_descriptor s, t;
    //double flow = kolmogorov_max_flow(g, s, t); // a list of sources will
be returned in s, and a list of sinks will be returned in t
    EdgeCapacityProperty flow = kolmogorov_max_flow(g, s, t); // a list of
sources will be returned in s, and a list of sinks will be returned in t
    std::cout << "Max flow is: " << flow << std::endl;

    return 0;
}

Thanks,

David