Re: [Boost-users] [Graph][parallel] Scale-free graph generator without self-loops

Subject: Re: [Boost-users] [Graph][parallel] Scale-free graph generator without self-loops
From: Borja Miñano (bminyano_at_[hidden])
Date: 2013-03-08 06:12:36

Hello again,

Following your advise I started trying with filter_iterator.
I could them filter in a in_edge iterator. But I was thinking on 
filtering the unique_rmat_iterator that I use to generate the graph (so 
I now understand why you said before creating the graph).
Unfortunately I got a compilation error that cannot figure out how to solve.
My filter is simple:

struct no_self_loops {
no_self_loops() {}
bool operator()(const std::pair<int,int>& e) { return e.first != e.second; }
};

And the the use is:

Graph g(
boost::make_filter_iterator<no_self_loops>(RMATGen(gen, 100, 1000, 0.57, 
0.19, 0.19, 0.05), RMATGen()),
boost::make_filter_iterator<no_self_loops>(RMATGen(), RMATGen()),
100);
and also tried with:
typedef boost::filter_iterator<no_self_loops, RMATGen > FilterIter;
no_self_loops predicate;
FilterIter filter_iter_first(predicate, RMATGen(gen, 100, 1000, 0.57, 
0.19, 0.19, 0.05), RMATGen());
FilterIter filter_iter_last(predicate, RMATGen(), RMATGen());

But the result is the same, the compilation errors are as follows:
...
/opt/boost_snap/include/boost/iterator/iterator_facade.hpp: En la 
instanciación de 
‘boost::iterator_facade<boost::filter_iterator<no_self_loops, 
boost::unique_rmat_iterator<boost::random::linear_congruential_engine<unsigned 
int, 48271u, 0u, 2147483647u>, boost::adjacency_list<boost::vecS, 
boost::distributedS<boost::graph::distributed::mpi_process_group, 
boost::vecS>, boost::bidirectionalS, VertexProperties, EdgeProperties> > 
 >, std::pair<long unsigned int, long unsigned int>, 
boost::single_pass_traversal_tag, const std::pair<long unsigned int, 
long unsigned int>&, void>’:
/opt/boost_snap/include/boost/iterator/iterator_adaptor.hpp:261:9: 
instanciado desde 
‘boost::iterator_adaptor<boost::filter_iterator<no_self_loops, 
boost::unique_rmat_iterator<boost::random::linear_congruential_engine<unsigned 
int, 48271u, 0u, 2147483647u>, boost::adjacency_list<boost::vecS, 
boost::distributedS<boost::graph::distributed::mpi_process_group, 
boost::vecS>, boost::bidirectionalS, VertexProperties, EdgeProperties> > 
 >, 
boost::unique_rmat_iterator<boost::random::linear_congruential_engine<unsigned 
int, 48271u, 0u, 2147483647u>, boost::adjacency_list<boost::vecS, 
boost::distributedS<boost::graph::distributed::mpi_process_group, 
boost::vecS>, boost::bidirectionalS, VertexProperties, EdgeProperties> 
 >, boost::use_default, boost::use_default, boost::use_default, 
boost::use_default>’
/opt/boost_snap/include/boost/iterator/filter_iterator.hpp:44:9: 
instanciado desde ‘boost::filter_iterator<no_self_loops, 
boost::unique_rmat_iterator<boost::random::linear_congruential_engine<unsigned 
int, 48271u, 0u, 2147483647u>, boost::adjacency_list<boost::vecS, 
boost::distributedS<boost::graph::distributed::mpi_process_group, 
boost::vecS>, boost::bidirectionalS, VertexProperties, EdgeProperties> > >’
filtro.cpp:235:112: instanciado desde aquí
/opt/boost_snap/include/boost/iterator/iterator_facade.hpp:584:7: error: 
tipo de parámetro 
‘boost::iterator_facade<boost::filter_iterator<no_self_loops, 
boost::unique_rmat_iterator<boost::random::linear_congruential_engine<unsigned 
int, 48271u, 0u, 2147483647u>, boost::adjacency_list<boost::vecS, 
boost::distributedS<boost::graph::distributed::mpi_process_group, 
boost::vecS>, boost::bidirectionalS, VertexProperties, EdgeProperties> > 
 >, std::pair<long unsigned int, long unsigned int>, 
boost::single_pass_traversal_tag, const std::pair<long unsigned int, 
long unsigned int>&, void>::difference_type {aka void}’ inválido
...

I couldn't change the language for the errors but its says something 
like " Parameter type 'boost::iterator_facade<boost...>::difference_type 
{aka void}’ invalid.
I cannot imagine where is my problem, could you help me?

El 08/03/13 10:03, Borja Miñano escribió:
> Hello Jeremiah,
>
> I have been looking for information and I have seen there is a 
> filtered_graph, maybe it is another option.
> I don't understand very well how the filter_iterator remove the 
> self-loops before creating the graph. Don't you refer after creating it?
>
> Thank you
>
> El 07/03/13 16:17, Jeremiah Willcock escribió:
>> On Thu, 7 Mar 2013, bminano wrote:
>>
>>> Hello,
>>>
>>> Does anyone knows if there is possible to generate a scale-free 
>>> graph that
>>> does not generate self-loops (edges with the same vertex for source and
>>> target)?
>>> I am using the unique_rmat_iterator, but it generates some 
>>> self-loops. I
>>> could remove them, but for the graph remains inconsistent because of 
>>> a bug.
>>>
>>> I will apreciate your help.
>>
>> One option would be to use a filter_iterator from Boost.Iterator to 
>> remove the self-loops before you create the graph.
>>
>> -- Jeremiah Willcock
>> _______________________________________________
>> Boost-users mailing list
>> Boost-users_at_[hidden]
>> http://lists.boost.org/mailman/listinfo.cgi/boost-users
>>
>
>

-- 
Un saludo,
Borja Miñano
IAC3 - Universitat de les Illes Balears
ParcBit - Edifici 17 (Disset); Local D7
Cra. Valldemossa km. 7,4
E-07121 Palma de Mallorca. Balears. Spain.
Phone: [phone]