Merge pull request #108 from personalrobotics/bugfix/issue99

Fixed two bugs in vectorfield planner.

Author: mkoval

src/prpy/planning/vectorfield.py

@@ -183,7 +183,7 @@ def TerminateMove():
 
     @PlanningMethod
     def FollowVectorField(self, robot, fn_vectorfield, fn_terminate,
-                          timelimit=5.0, dt_multiplier=1.0, **kw_args):
+                          timelimit=5.0, dt_multiplier=1.01, **kw_args):
         """
         Follow a joint space vectorfield to termination.
 
@@ -228,7 +228,7 @@ def FollowVectorField(self, robot, fn_vectorfield, fn_terminate,
 
                     dqout = fn_vectorfield()
                     numsteps = int(math.floor(max(
-                        dqout*dt_step/robot.GetActiveDOFResolutions()
+                        abs(dqout*dt_step/robot.GetActiveDOFResolutions())
                         )))
                     if numsteps == 0:
                         raise PlanningError('Step size too small, '