added post-processing script for animated force-directed graph layout.

diff --git a/src/Dyna/Backend/Python/graph.py b/src/Dyna/Backend/Python/graph.py
new file mode 100644 (file)
index 0000000..c6d01de
--- /dev/null
+++ b/src/Dyna/Backend/Python/graph.py
@@ -0,0 +1,39 @@
+import pylab as pl
+from matplotlib.animation import FuncAnimation
+from collections import defaultdict
+
+def g(nodes, edges, t, ax, interp):
+    ax.cla()
+    ax.set_title(t)
+    ax.set_xlim(-2,2)
+    ax.set_ylim(-2,2)
+
+    pos = defaultdict(lambda: (0,0))
+    pos.update({node: p for _, (node, _, p) in interp.chart['pos/2'][:,t,:]})
+
+    for u,v in edges:
+        if u < v:
+            (a,b), (c,d) = pos[u], pos[v]
+            ax.plot([a,c], [b,d])
+
+    for s in nodes:
+        x,y = pos[s]
+        ax.text(x,y,s)
+
+def animate(interp):
+    [(_, (niter,))] = interp.chart['niter/0'][:,]
+
+    nodes = [name for _, (name, _) in interp.chart['node/1'][:,:]]
+    edges = [(u,v) for _, (u,v,_) in interp.chart['edge/2'][:,:,:]]
+
+    fig = pl.figure()
+    ax = pl.axes()
+
+    print 'creating animation..'
+    anim = FuncAnimation(fig, lambda t: g(nodes, edges, t % niter, ax, interp), frames=niter*3)
+    print 'saving...'
+    anim.save('examples/force.dyna.mp4', fps=30, extra_args=['-vcodec', 'libx264'])
+    print 'wrote examples/force.dyna.mp4'
+
+
+animate(interp)