Re: [Boost-users] Default weight map doesn't work for weighted grid graph in A-star search

Subject: Re: [Boost-users] Default weight map doesn't work for weighted grid graph in A-star search
From: W.P. McNeill (billmcn_at_[hidden])
Date: 2010-07-14 19:59:02

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:

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

>  I was surprised by this because I expected the filtered graph to inherit
>> the grid graph's vertex index map like you describe.
>>
>
> That is what it should do.
>
> -- Jeremiah Willcock
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