kernel/graph.py

A simple example showing how to use the graph interface for in python.

## \example kernel/graph.py
## A simple example showing how to use the graph interface for in python.

import IMP

m= IMP.Model()
# An undirected graph with an IMP::Object for each node
g= IMP.DependencyGraph()
vs=[]
ps=[]
for i in range(0,10):
    ps.append(IMP.Particle(m))
    vs.append(g.add_vertex(ps[-1]));
g.add_edge(vs[0], vs[1])
g.add_edge(vs[1], vs[2])

#try to use the altgraph package to visualize
IMP.show_graphviz(g)
try:
    IMP.show_graphviz(g)
except:
    print "Oh well, no altgraph"

try:
    import matplotlib
    # the engine to be used must be selected before pyplot is imported
    matplotlib.use("macosx")
    import matplotlib.pyplot as plt

    # the method below requires the altgraph python package
    xg=IMP.get_networkx_graph(g)

    # the networkx visualization tools suck, so skip them
    #import networkx
    #networkx.draw(xg)
    #networkx.draw_shell(xg)
    #plt.show()
except:
    print "networkx not fully installed"

g.remove_vertex(0)

# we can also try another show method
try:
    IMP.show_graphviz(g)
except:
    print "oh well, something not working with graphviz"

# finally, we can
# in and out neighbors are the same
for n in g.get_in_neighbors(8):
    print g.get_vertex_name(n).get_name()