SaveGraphCore
(
IGraph graph,
Stream stream
)
{
Debug.Assert(graph != null);
Debug.Assert(stream != null);
AssertValid();
// The Pajek format requires coordinates to be between 0 and 1.0. Get
// a Matrix that will transform the vertex locations to this range.
RectangleF oCurrentBoundingRectangle =
LayoutUtil.GetGraphBoundingRectangle(graph);
RectangleF oNewBoundingRectangle =
new RectangleF(PointF.Empty, new SizeF(1.0F, 1.0F));
Matrix oRectangleTransformation =
LayoutUtil.GetRectangleTransformation(
oCurrentBoundingRectangle, oNewBoundingRectangle
);
// Create a dictionary to keep track of vertices. The keys are vertex
// IDs and the values are the one-based vertex numbers used by the
// Pajek format.
Dictionary <Int32, Int32> oVertexIDToNumber =
new Dictionary <Int32, Int32>();
IVertexCollection oVertices = graph.Vertices;
StreamWriter oStreamWriter = new StreamWriter(stream, StreamEncoding);
// Add the *vertices section.
oStreamWriter.WriteLine(
"*vertices {0}"
,
oVertices.Count
);
Int32 iVertexNumber = 1;
foreach (IVertex oVertex in oVertices)
{
// Format:
//
// 1 "vertex 1 name" x y z
// Transform the vertex location.
PointF oTransformedLocation = LayoutUtil.TransformPointF(
oVertex.Location, oRectangleTransformation);
// Limit the range in case of rounding errors.
Single fX = Math.Max(0F, oTransformedLocation.X);
fX = Math.Min(1F, fX);
Single fY = Math.Max(0F, oTransformedLocation.Y);
fY = Math.Min(1F, fY);
oStreamWriter.WriteLine(
"{0} \"{1}\" {2:N6} {3:N6} 0"
,
iVertexNumber,
oVertex.Name,
fX,
fY
);
oVertexIDToNumber.Add(oVertex.ID, iVertexNumber);
iVertexNumber++;
}
IEdgeCollection oEdges = graph.Edges;
GraphDirectedness eDirectedness = graph.Directedness;
Boolean bSectionNameWritten = false;
if (eDirectedness != GraphDirectedness.Directed)
{
// If appropriate, add the *edges section, which specifies
// undirected edges.
foreach (IEdge oEdge in oEdges)
{
// The graph could be mixed.
if (oEdge.IsDirected)
{
continue;
}
if (!bSectionNameWritten)
{
oStreamWriter.WriteLine("*edges");
bSectionNameWritten = true;
}
WriteEdge(oEdge, oVertexIDToNumber, oStreamWriter);
}
}
bSectionNameWritten = false;
if (eDirectedness != GraphDirectedness.Undirected)
{
// If appropriate, add the *arcs section, which specifies
// directed edges.
foreach (IEdge oEdge in oEdges)
{
// The graph could be mixed.
if (!oEdge.IsDirected)
{
continue;
}
if (!bSectionNameWritten)
{
oStreamWriter.WriteLine("*arcs");
bSectionNameWritten = true;
}
WriteEdge(oEdge, oVertexIDToNumber, oStreamWriter);
}
}
oStreamWriter.Flush();
}