Re: [Boost-users] newbie - graph library - vertex properties

Subject: Re: [Boost-users] newbie - graph library - vertex properties
From: Suresh Kumar (suresh.amritapuri_at_[hidden])
Date: 2009-12-16 20:00:44

Hi,

For example, I wrote the following:
 typedef property_map<Map, double Highway::*>::const_type IndexMap;
 IndexMap index = get(&Highway::miles,map);

But I am unable to figure out how to get the actual vertex property
from the IndexMap index.

Also, how do we use, get(vertex_bundle, map)?

Thanks
suresh

On Wed, Dec 16, 2009 at 4:09 PM, Suresh Kumar
<suresh.amritapuri_at_[hidden]> wrote:
> Hi Tobias,
>
> Can you just show, how to access the vertex properties using the get()
>  function?. I know that map[vertex_descriptior] gives me the
> vertex_properties of that particular vertex. But I am unable to figure
> out how to use the get function for single vertex property as well as
> for the vertex_bundle,
>
> Thanks
> suresh
>
> On Tue, Dec 15, 2009 at 3:18 PM, Tobias Columbus <t.columbus_at_[hidden]> wrote:
>> Hi again,
>>
>> Try the following code, which just compiles fine with g++ 4.4.1 on my
>> system:
>>
>> struct City{...};
>> struct Highway{...};
>>
>> typedef ... Map;
>>
>> int main(){
>> Map map;
>> Map::vertex_descriptor v = add_vertex( map );
>> Map::vertex_descriptor u = add_vertex( map );
>> map[v].name = "Troy";
>> map[v].population = 49170;
>> map[v].zipcodes.push_back(12180);
>> Map::edge_descriptor e = add_edge( u, v, map ).first;
>> map[e].name = "I-87";
>> map[e].miles = 10;
>> map[e].speed_limit = 65;
>> map[e].lanes = 4;
>> map[e].divided = true;
>> return 0;
>> }
>>
>> Generally I would suggest reading
>> http://www.boost.org/doc/libs/1_41_0/libs/graph/doc/quick_tour.html
>> which gives a quick overview of how to handle graphs in BGL.
>>
>> If you work through this tutorial, vertex and edge properties will also
>> get explained.
>>
>> Regards
>> Tobias
>>
>> On Tuesday 15 December 2009 05:00:01 pm List User wrote:
>>> Hi Tobias Columbus,
>>>
>>> In fact I had tried that also. But then I got a funny message while
>> executing like this: Ubuntu 9.04, g++ 4.3.3
>>> //Map::vertex_descriptor v = *vertices(map).first;
>>>  Map::vertex_descriptor v = add_vertex(map);
>>>
>>> suresh_at_suresh-laptop:~/C++$ ./a.out
>>> *** glibc detected *** ./a.out: free(): invalid pointer: 0x09f9c064
>> ***
>>> ======= Backtrace: =========
>>> /lib/tls/i686/cmov/libc.so.6[0xb7e6a604]
>>> /lib/tls/i686/cmov/libc.so.6(cfree+0x96)[0xb7e6c5b6]
>>> /usr/lib/libstdc++.so.6(_ZdlPv+0x21)[0xb804d231]
>>> ../a.out[0x8049e7d]
>>> ../a.out[0x8049ea7]
>>> ..
>>> ..
>>> ..
>>>
>>> so what to do next?
>>>
>>> suresh
>>>
>>>
>> _______________________________________________
>> Boost-users mailing list
>> Boost-users_at_[hidden]
>> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>>
>
>
>
> --
> R. Suresh Kumar
> PhD Student, Vislab
> #216, Engineering II Bldg
> University of California, Riverside,
> CA 92521
>

-- 
R. Suresh Kumar
PhD Student, Vislab
#216, Engineering II Bldg
University of California, Riverside,
CA 92521