使用BOOST复制具有顶点和属性的边 [英] copying edges with their vertices and properties using BOOST

问题描述

我想从dataG.front（）复制具有顶点和属性的边，并将其添加到testg，我尝试了在访问绑定属性部分 http://www.boost.org/doc/libs/1_57_0/libs/graph/doc/bundles.html 但它不为我工作。 PS：dataG是图形的向量。

I want to copy edges with their vertices and properties from dataG.front(), and add it to testg , I tried what I found in "Accessing bundled properties" section http://www.boost.org/doc/libs/1_57_0/libs/graph/doc/bundles.html but it isn't working for me. PS: dataG is a vector of graphs.

typedef std::pair<edge_iter, edge_iter> edge_pair;
Graph testg;
if (!dataG.empty()) 
{
    auto const& gr = dataG.front();         
    for (edge_pair ep = edges(gr); ep.first != ep.second; ++ep.first) //ep edge number 
    {
        auto ep = edges(gr).first;  // ep edge number

        vertex_t from = source(*ep.first, gr);
        vertex_t to   = target(*ep.first, gr);

        boost::add_vertex(gr[from], testg);
        boost::add_vertex(gr[to], testg);

        boost::add_edge(from, to, gr[*ep.first], testg);

    }
}

问题在源和目标。 （vertex_t和add_vertex部分），如何直接添加顶点属性到添加的一个，因为这里有一个重复。

edges properties works but there is a problem in source and target. (vertex_t and add_vertex part), How to add directly the vertices properties to the added one because there is a duplication here.

PS：更多的信息在这里是完整的代码 http://pastebin.com/2iztGAa6

PS: for more information here is the full code http://pastebin.com/2iztGAa6

推荐答案

您注意到，顶点可能会重复，如果您将多个源图形合并为一个图形，这一点尤其真实。

As you noticed, the vertices might be duplicated, and this is especially true if you "merge" multiple of the source graphs into one graph.

如果您不介意重写顶点属性（并保持最后分配的值，以防值不一致），您只需使用属性映射：

If you don't mind to re-write the vertex properties (and keeping the value last assigned in case the values aren't identical all the time) you can just use a property map:

boost::property_map<Graph, boost::vertex_bundle_t>::type vpmap = boost::get(boost::vertex_bundle, testg);

//so:
vpmap[from] = gr[from];
vpmap[to]   = gr[to];

再次，还有类似的访问：

Then again, there's also the equivalent access like so:

testg[from] = gr[from];
testg[to]   = gr[to];

您甚至可以添加单独的捆绑成员：

You can even addres individual bundled members:

boost::property_map<Graph, int VertexProperties::*>::type idmap    = boost::get(&VertexProperties::id, testg);
boost::property_map<Graph, int VertexProperties::*>::type labelmap = boost::get(&VertexProperties::label, testg);
idmap[from]    = gr[from].id;
labelmap[from] = gr[from].label;

基于此文档页

这篇关于使用BOOST复制具有顶点和属性的边的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！