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baxter-flowers / promplib

Python implementation of Probabilistic Motor Primitives including a ROS overlay to be used with JointTrajectory, JointState and RobotTrajectory, RobotState (Move It) messages
GNU Lesser General Public License v3.0
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Issue with accounting for via points in TaskProMP #4

Open karthikm-0 opened 3 years ago

karthikm-0 commented 3 years ago

Hi,

Thank you for providing this very useful ProMP library! I had a question while implementing a TaskProMP. I am unable to have the provided demonstration take via points into account, and as a result, the generated trajectory is exactly the same as the demonstration. I was looking into the implementation details and noticed that the update step to account for each via point does not update the mean or covariance matrices - the addition term does not have an effect (lines 268-270 in promp.py), which explains why the generated trajectory is the same. I was wondering if you'd have any thoughts on how to fix this.

Thanks!

ymollard commented 3 years ago

You might meet incompatibilities coming from Python 3 or recent numpy/scipy versions. This library has not been maintained for 4 years and would honestly need a refresh for anyone willing to inspire from it.

Maybe test with some python/numpy/scipy versions that were alive in 2017 to observe if your issue still occurs. Comparing with conditioning equations from the original paper could also help. Also provide a test snippet.

karthikm-0 commented 3 years ago

Hi @ymollard thanks for bringing up the point about the Python/Numpy/Scipy versions. I've fixed the issue now using a consistent set of versions.