Hi hitesh, It would help if you cut and paste the exact error message and include a sample program. I suspect that the program is using the subscriber object instead of the message object, but this is hard to tell without more information. Ken On Apr 18, 2010 9:43 AM, "hitesh dhiman" wrote: Hi all, I'm trying to subscribe to the cmd_vel message, According to the definition, the message is of type Twist, with 2 vectors linear and angular. My node to access this topic is in python. For example, if the subscriber is vel = rospy.Subscriber("/cmd_vel", Twist) if i try to print out vel.linear, it gives an attribute error, stating the subscriber object has no attribute linear. Any idea what I'm doing wrong here? -- Regards, Hitesh Dhiman Electrical Engineering National University of Singapore ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ ros-users mailing list ros-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/ros-users _______________________________________________ ros-users mailing list ros-users@code.ros.org https://code.ros.org/mailman/listinfo/ros-users