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Subject: Re: [Boost-users] Default weight map doesn't work for weighted grid graph in A-star search
From: Jeremiah Willcock (jewillco_at_[hidden])
Date: 2010-07-14 20:04:13

On Wed, 14 Jul 2010, W.P. McNeill wrote:

> On Wed, Jul 14, 2010 at 3:16 PM, Jeremiah Willcock <jewillco_at_[hidden]> wrote:
> On Wed, 14 Jul 2010, W.P. McNeill wrote:
> I verified the documentation changes for grid graph indexing calls and A* visitors.  Looks good. Now doing edge weights with
> a static_property_map<>.
> OK.
> I've duplicated relevant information from the README at the top of maze.cpp, so README doesn't need to be included in the Boost examples.
> I found that I have to implement my own vertex index map, though I'm not sure exactly why.  If I remove all my vertex index map code and
> call A* with the
> default map like so:
>     astar_search(m_barrier_grid,
>                  source(),
>                  heuristic,
>                  boost::weight_map(weight).
>                  predecessor_map(pred_pmap).
>                  distance_map(dist_pmap).
>                  visitor(visitor) );
> I get the following error:
> (snip)
> That is a bug in astar_search().  Please try with the latest Boost trunk and see if it works.  I also added named parameters to
> astar_search_no_init().
> I tried building with the default index map again against the Boost tree at version 64026 and got the same error as before:

OK. See if any of the later changes I did affect this too.

> graph_traits.hpp:226: error: no type named ‘vertex_property_type’ in
> ‘class grid’   I noticed that the documentation for the the
> vertex_index_map parameter says that the graph must have an internal
> vertex_index property.  Could this be the problem?  If I try to add the
> following line to a working build:
> typedef grid::vertex_index grid_vertex_index;
> I get this error:
> g++ -g -I/src/boost-trunk -Wall -Werror -O3   -c -o astar_maze.o astar_maze.cpp
> astar_maze.cpp:62: error: ‘vertex_index’ in class ‘grid’ does not name a type

What is supposed to work is:

boost::property_map<grid, boost::vertex_index>::const_type pm
    = get(boost::vertex_index, grid());

If that succeeds, it's an algorithm bug most likely.

-- Jeremiah Willcock

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