[Lemon-user] question about write data to lgf file

[Alpár Jüttner]

Hi,
>      digraphWriter(g, "out.lgf")
>          .nodeMap("Name", name)
>          .run();
> 
> The map "name" can be written to file in this way, but how to write the 
> " vessel_property" map? I want to output and read it's "Vol", "Temp" etc.

One way is that you write a function (or functor) vessel_to_str() that
takes a vessel as input and returns a string representation. Then you
can add this as the third argument to nodemap():

digraphWriter(g, "out.lgf")
          .nodeMap("vessel_pr", vessel_property, vessel_to_str)
          .run();

The reading is node similarly.

If you want to save a single member to the lgf, you can write also map
adaptor:

class VesselVol
{
public:
  typedef ListDigraph::Node Key;
  typedef double Value;

  ListDigraph::NodeMap<vessel> &vessel_property;

  VesselVol(ListDigraph::NodeMap<vessel> &v) :vessel_property(v) {};

  double &operator[](Key n) { return vessel_property[n].Vol; }
  void set(Key n,double v) { vessel_property[n].Vol=v; }
}

VesselVol vv(vessel_property);
digraphWriter(g, "out.lgf")
          .nodeMap("vessel_vol", vv)
          .run();
digraphReader(g, "out.lgf")
          .nodeMap("vessel_vol", vv)
          .run();


Regards:
Alpar