Question

一个boost :: adjaceny_list我能够得到并设置图形的名称。可悲的是，我无法将其保存并加载到文件中。我可以保存和加载顶点和边缘，但图形属性的工作方式不同。

在下面的完整测试编译代码中，我展示了：

如何创建名为
设置并获取图表名称
加载并保存图表
main：设置图表名称，保存，加载，检查结果是否仍具有该名称

首先是基础工作：

如何创建名为
设置并获取图表名称

这些功能接近于简单：

#include <boost/graph/adjacency_list.hpp>
#include <string>

boost::adjacency_list<
  boost::vecS,
  boost::vecS,
  boost::directedS,
  boost::no_property,
  boost::no_property,
  boost::property<boost::graph_name_t,std::string>
>
create_empty_directed_graph_with_graph_name() noexcept
{
  return {};
}

template <typename graph>
void set_graph_name(const std::string& name, graph& g) noexcept
{
  get_property(g, boost::graph_name) = name;
}

template <typename graph>
std::string get_graph_name(const graph& g) noexcept
{
  return get_property(g, boost::graph_name
  );
}

我想去上班的考试：

int main()
{
  const std::string dot_filename{"test.dot"};
  auto g = create_empty_directed_graph_with_graph_name();
  set_graph_name("TestGraph", g);
  save_graph_with_graph_name_to_dot(g, dot_filename);
  const auto h = load_directed_graph_with_graph_name_from_dot(dot_filename);
  assert(get_graph_name(g) == get_graph_name(h));
}

步骤是：（1）设置图形名称（2）保存（3）加载图形（4）检查是否具有相同名称

我所提出的代码是保存。我用这样的名字保存图表：

template <typename graph>
void save_graph_with_graph_name_to_dot(
  const graph& g, const std::string& filename
)
{
  std::ofstream f(filename);
  boost::write_graphviz(
    f,
    g,
    boost::default_writer(),
    boost::default_writer(),
    [g](std::ostream& os) {
      os << "name=\""
        << get_graph_name(g)
        << "\";\n";
    }
  );
}

我不确定这是否可行。它生成以下.dot文件：

digraph G {
name="TestGraph";
}

我想知道它是不是应该说＆＃39; digraph TestGraph＆＃39;相反，它被接受为有效的.dot文件。

加载此文件是我被困在的地方。我甚至不知道如何编译它。我知道如何（保存和）加载任何类型的边和顶点（见a Boost.Graph tutorial），但在这里我迷路了。这是我的尝试：

boost::adjacency_list<
  boost::vecS,
  boost::vecS,
  boost::directedS,
  boost::no_property,
  boost::no_property,
  boost::property<boost::graph_name_t, std::string>
>
load_directed_graph_with_graph_name_from_dot(
  const std::string& dot_filename
)
{
  std::ifstream f(dot_filename.c_str());
  auto g = create_empty_directed_graph_with_graph_name();

  //#define TODO_KNOW_HOW_TO_LOAD_A_GRAPH_ITS_NAME
  #ifdef TODO_KNOW_HOW_TO_LOAD_A_GRAPH_ITS_NAME
  boost::dynamic_properties p;
  p.property("name",get_property(g,boost::graph_name)); //Something like this?
  #else
  boost::dynamic_properties p(
    boost::ignore_other_properties
  );
  #endif
  boost::read_graphviz(f,g,p);
  return g;
}

我希望有人知道如何保存和加载带有名称的图表。它不应该太难了，不应该吗？

以下是完整的完整列表：

#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/graphviz.hpp>
#include <boost/graph/properties.hpp>
#include <cassert>
#include <fstream>
#include <string>

boost::adjacency_list<
  boost::vecS,
  boost::vecS,
  boost::directedS,
  boost::no_property,
  boost::no_property,
  boost::property<boost::graph_name_t,std::string>
>
create_empty_directed_graph_with_graph_name() noexcept
{
  return {};
}

template <typename graph>
void set_graph_name(const std::string& name, graph& g) noexcept
{
  get_property(g, boost::graph_name) = name;
}

template <typename graph>
std::string get_graph_name(const graph& g) noexcept
{
  return get_property(g, boost::graph_name
  );
}

template <typename graph>
void save_graph_with_graph_name_to_dot(
  const graph& g, const std::string& filename
)
{
  std::ofstream f(filename);
  boost::write_graphviz(
    f,
    g,
    boost::default_writer(),
    boost::default_writer(),
    //Unsure if this results in a graph that can be loaded correctly from a .dot file
    [g](std::ostream& os) {
      os << "name=\""
        << get_graph_name(g)
        << "\";\n";
    }
  );
}

boost::adjacency_list<
  boost::vecS,
  boost::vecS,
  boost::directedS,
  boost::no_property,
  boost::no_property,
  boost::property<boost::graph_name_t, std::string>
>
load_directed_graph_with_graph_name_from_dot(
  const std::string& dot_filename
)
{
  std::ifstream f(dot_filename.c_str());
  auto g = create_empty_directed_graph_with_graph_name();

  //#define TODO_KNOW_HOW_TO_LOAD_A_GRAPH_ITS_NAME
  #ifdef TODO_KNOW_HOW_TO_LOAD_A_GRAPH_ITS_NAME
  boost::dynamic_properties p;
  p.property("name",get_property(g,boost::graph_name)); //Something like this?
  #else
  boost::dynamic_properties p(
    boost::ignore_other_properties
  );
  #endif
  boost::read_graphviz(f,g,p);
  return g;
}

int main()
{
  const std::string dot_filename{"test.dot"};
  auto g = create_empty_directed_graph_with_graph_name();
  set_graph_name("TestGraph", g);
  save_graph_with_graph_name_to_dot(g, dot_filename);
  const auto h = load_directed_graph_with_graph_name_from_dot(dot_filename);
  assert(get_graph_name(g) == get_graph_name(h));
}

Answer 1

cv_and_he：谢谢！我确实看到了这个页面，但很难读到它！

答案：代码的加载部分需要更改为：

boost::adjacency_list<
  boost::vecS,
  boost::vecS,
  boost::directedS,
  boost::no_property,
  boost::no_property,
  boost::property<boost::graph_name_t, std::string>
>
load_directed_graph_with_graph_name_from_dot(
  const std::string& dot_filename
)
{
  using graph = boost::adjacency_list<
    boost::vecS,
    boost::vecS,
    boost::directedS,
    boost::no_property,
    boost::no_property,
    boost::property<boost::graph_name_t, std::string>
  >;


  std::ifstream f(dot_filename.c_str());
  auto g = create_empty_directed_graph_with_graph_name();

  boost::ref_property_map<graph*,std::string>
    graph_name(get_property(g,boost::graph_name)
  );

  boost::dynamic_properties dp;
  dp.property("name",graph_name);

  boost::read_graphviz(f,g,dp);
  return g;
}

Boost.Graph：保存并加载名为

1 个答案: