petercorke / petercorke/robotics-toolbox-python
Inconsistent joint indexes in ETS
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Description
Describe the bug
Multiplication (concatenation) of several ETS does not update joint indexes
Version information
roboticstoolbox-python 1.1.0
To Reproduce
import roboticstoolbox as rtb
et = rtb.ET.Rz()
ets = rtb.ETS([et, ])
print((et * et).joints()) # OK:
# [ET.Rz(jindex=0), ET.Rz(jindex=1)]
print((ets * ets).joints()) # NOT OK:
# [ET.Rz(jindex=0), ET.Rz(jindex=0)]
print((et * et * ets).joints()) # NOT OK:
# [ET.Rz(jindex=0), ET.Rz(jindex=1), ET.Rz(jindex=0)]
print((et * ets).joints()) # NOT OK:
# raise ValueError( "You can not have some jindices set for the ET's in arg. It must be all")
Expected behavior
ETS consctructor should re-enumerate joint indexes
Environment (please complete the following information):
- Ubuntu 22.04
- python 3.10.6
p.s. Awesome work btw :) !!!
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the ETS constructor and the joints() behavior shown in the reproduction. Run the provided examples for concatenating ET and ETS objects, then make the constructor re-enumerate joint indexes so the resulting joints have distinct indexes and the mixed concatenation no longer raises the reported ValueError.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 3/5
- Estimated time
- 1-2 days
- Activity status
- Stale
- Clarity
- Clearly specified
- Newbie friendliness
- 45/100