add a PR2 IK demo

drake/bindings/python/.gitignore

@@ -2,3 +2,4 @@
 pydrake/rbtree.py
 pydrake/autodiffutils.py
 pydrake/solvers/ik.py
+*.pyc

drake/bindings/python/pydrake/test/testPR2IK.py

@@ -0,0 +1,28 @@
+import os
+import numpy as np
+import pydrake
+from pydrake.solvers import ik
+
+robot = pydrake.rbtree.RigidBodyTree(os.path.join(pydrake.getDrakePath(), "examples/PR2/pr2.urdf"))
+print robot.bodies
+print robot.bodies[0]
+
+constraints = [ik.WorldPositionConstraint(robot, 1,
+                                          np.zeros((3,)),
+                                          np.array([0,0,1.0]),
+                                          np.array([0,0,1.0])),
+               ik.WorldPositionConstraint(robot, robot.findLink("r_gripper_palm_link").body_index,
+                                          np.zeros((3,)),
+                                          np.array([0.5,0,1.5]),
+                                          np.array([0.5,0,1.5])),
+               ]
+print constraints
+
+q_seed = robot.getZeroConfiguration()
+options = ik.IKoptions(robot)
+results = ik.inverseKinSimple(robot, q_seed, q_seed, constraints, options)
+print results
+print repr(results.q_sol)
+
+
+# print robot.getBody0()