Hey Mat, In the write function in graph_types/graph_drawing.h, for each vertex and edge property the following call is used: _streamWrite(file, getProperty(nodeMap, *itVertex)); _streamWrite(file, getProperty(edgeMap, *itEdge)); Best, Tobias ________________________________________ From: Mat [matthias.dodt@mdc-berlin.de] Sent: Monday, February 07, 2011 4:34 PM To: SeqAn Development Subject: [Seqan-dev] Using EdgeProperties and VertexProperties Hey guys! I would like to create a .dot file of my graph using the write(strmWrite, *graph, *vertexPropertyMap,*edgePropertyMap,DotDrawing()); method. The two maps are defined as follows: seqan::String<VertexProperty> *vertexPropertyMap = new seqan::String<VertexProperty>(); seqan::String<EdgeProperty> *edgePropertyMap = new seqan::String<EdgeProperty>(); VertexProperty and EdgeProperty are two custom classes... Now if i use the DotDrawing() method i get the message "cannot convert form VertexProperty to char"... So i guess i would have to implement my own "_streamPut" method for these classes in seqans "cstream.h", so something like: inline void _streamPut(::std::FILE * target, const EdgeProperty e) { SEQAN_CHECKPOINT //putc(e.toChar(), target); } or is there an easier way to do that? Thanks! best, mat