Add graph_tool.draw module

This adds a graph_draw() functions which draws graphs in variety of
layouts and formats, and also to the screen, using the python graphviz
bindings.

src/graph_tool/Makefile.am

@@ -34,3 +34,7 @@ graph_tool_statsdir = $(pythondir)/graph_tool/stats
 graph_tool_clustering_PYTHON = \
     clustering/__init__.py
 graph_tool_clusteringdir = $(pythondir)/graph_tool/clustering
+
+graph_tool_draw_PYTHON = \
+    draw/__init__.py
+graph_tool_drawdir = $(pythondir)/graph_tool/draw

src/graph_tool/draw/__init__.py

+#! /usr/bin/env python
+# graph_tool.py -- a general graph manipulation python module
+#
+# Copyright (C) 2007 Tiago de Paula Peixoto <tiago@forked.de>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import sys,os
+import matplotlib.cm
+import matplotlib.colors
+from .. core import _degree, _prop, PropertyMap
+from .. decorators import _limit_args
+import gv
+
+def graph_draw(g, pos=None, size=(15,15), pin=False, layout="neato",
+               maxiter=None, ratio="fill", overlap=False, splines=False,
+               mode="ipsep", penwidth=1.0, eweight=None, ewidth=None, gprops={},
+               vprops={}, eprops={}, vcolor=None, ecolor=None,
+               vcmap=matplotlib.cm.jet, vnorm=True, ecmap=matplotlib.cm.jet,
+               enorm=True, output=None, output_format=None):
+    """Draw a graph using graphviz."""
+
+    if g.is_directed():
+        gvg = gv.digraph("G")
+    else:
+        gvg = gv.graph("G")
+
+    # main graph properties
+    gv.setv(gvg,"outputorder", "edgesfirst")
+    gv.setv(gvg,"mode", mode)
+    if overlap == "false" and layout == "neato" and mode == "ipsep":
+        overlap = "ipsep"
+    if overlap:
+        gv.setv(gvg,"overlap", "true")
+    elif isinstance(overlap,str):
+        gv.setv(gvg,"overlap", overlap)
+    if splines:
+        gv.setv(gvg,"splines", "true")
+    gv.setv(gvg,"ratio", str(ratio))
+    gv.setv(gvg,"size", "%f,%f" % (size[0]/2.54,size[0]/2.54)) # centimeters
+    if maxiter != None:
+        gv.setv(gvg,"maxiter", str(maxiter))
+
+    # apply all user supplied properties
+    for k,val in vprops:
+        if isinstance(val, PropertyMap):
+            gv.setv(gvg, k, str(val[g]))
+        else:
+            gv.setv(gvg, k, str(val))
+
+    # normalize color properties
+    if vcolor != None and not isinstance(vcolor, str):
+        minmax = [float("inf"), -float("inf")]
+        for v in g.vertices():
+            c = vcolor[v]
+            minmax[0] = min(c,minmax[0])
+            minmax[1] = max(c,minmax[1])
+        print minmax
+        if vnorm:
+            vnorm = matplotlib.colors.normalize(vmin=minmax[0], vmax=minmax[1])
+
+    if ecolor != None and not isinstance(ecolor, str):
+        minmax = [float("inf"), -float("inf")]
+        for e in g.edges():
+            c = ecolor[v]
+            minmax[0] = min(c,minmax[0])
+            minmax[1] = max(c,minmax[1])
+        if enorm:
+            enorm = matplotlib.colors.normalize(vmin=minmax[0], vmax=minmax[1])
+
+    nodes = []
+    edges = []
+
+    # add nodes
+    for v in g.vertices():
+        n = gv.node(gvg,str(g.vertex_index[v]))
+        gv.setv(n, "width", "0.1")
+        gv.setv(n, "height", "0.1")
+        gv.setv(n, "height", "0.1")
+        gv.setv(n, "style", "filled")
+        gv.setv(n, "color", "black")
+        # apply color
+        if vcolor != None:
+            if isinstance(vcolor,str):
+                gv.setv(n, "fillcolor", vcolor)
+            else:
+                color = tuple([int(c*255.0) for c in vcmap(vnorm(vcolor[v]))])
+                gv.setv(n, "fillcolor", "#%.2x%.2x%.2x%.2x" % color)
+        else:
+            gv.setv(n, "fillcolor", "red")
+        gv.setv(n, "label", "")
+
+        # user supplied position
+        if pos != None:
+            gv.setv(n, "pos", "%f,%f" % (pos[0][v],pos[1][v]))
+            gv.setv(n, "pin", str(pin))
+
+        # apply all user supplied properties
+        for k,val in vprops:
+            if isinstance(val, PropertyMap):
+                gv.setv(n, k, str(val[v]))
+            else:
+                gv.setv(n, k, str(val))
+        nodes.append(n)
+    for e in g.edges():
+        ge = gv.edge(nodes[g.vertex_index[e.source()]],
+                     nodes[g.vertex_index[e.target()]])
+        gv.setv(ge, "arrowsize", "0.3")
+        gv.setv(ge, "arrowhead", "vee")
+        # apply color
+        if ecolor != None:
+            if isinstance(ecolor,str):
+                gv.setv(ge, "color", ecolor)
+            else:
+                color = tuple([int(c*255.0) for c in ecmap(enorm(ecolor[e]))])
+                gv.setv(ge, "color", "#%.2x%.2x%.2x%.2x" % color)
+
+        # apply weight
+        if eweight != None:
+            if isinstance(eweight, PropertyMap):
+                gv.setv(ge, "weight", str(eweight[e]))
+            else:
+                gv.setv(ge, "weight", str(eweight))
+
+        # apply width
+        if ewidth != None:
+            if isinstance(ewidth, PropertyMap):
+                gv.setv(ge, "penwidth", str(ewidth[e]))
+            else:
+                gv.setv(ge, "penwidth", str(ewidth))
+
+        # apply all user supplied properties
+        for k,v in eprops:
+            if isinstance(v, PropertyMap):
+                gv.setv(ge, k, str(v[e]))
+            else:
+                gv.setv(ge, k, str(v))
+        edges.append(ge)
+
+    gv.layout(gvg, layout)
+    gv.render(gvg, "dot", "/dev/null") # retrieve postitions
+
+    if pos == None:
+        pos = (g.new_vertex_property("double"), g.new_vertex_property("double"))
+    for n in xrange(0, len(nodes)):
+        p = gv.getv(nodes[n], "pos")
+        p = p.split(",")
+        pos[0][g.vertex(n)] = float(p[0])
+        pos[1][g.vertex(n)] = float(p[1])
+    if output == None:
+        output = ""
+        output_format = "xlib"
+    elif output_format == None:
+        outout_format = output.split(".")[-1]
+
+    # if using xlib we need to fork the process, otherwise good ol' graphviz
+    # will call exit() when the window is closed
+    if output_format == "xlib":
+        pid = os.fork()
+        if pid == 0:
+            gv.render(gvg, output_format, output)
+            sys.exit(1) # since we forked, it's good to be sure
+        os.wait()
+    else:
+        gv.render(gvg, output_format, output)
+    gv.rm(gvg)
+    return pos