[DEFECT] Multi Objective GA - crossover crash with 2 variables

[alfoa]

Thank you for the defect report

• I am using the latest version of RAVEN.
• I have read the Wiki.
• I have created a minimum, reproducible example
  that demonstrates the defect.

Defect Description

( 34.99 sec) GeneticAlgorithm : DEBUG -> ### rlz.sizes['RAVEN_sample_ID'] = 50 Traceback (most recent call last): File "/Users/aalfonsi/projects/raven/raven_framework.py", line 25, in <module> sys.exit(main(True)) ^^^^^^^^^^ File "/Users/aalfonsi/projects/raven/ravenframework/Driver.py", line 207, in main raven() File "/Users/aalfonsi/projects/raven/ravenframework/Driver.py", line 160, in raven simulation.run() File "/Users/aalfonsi/projects/raven/ravenframework/Simulation.py", line 909, in run self.executeStep(stepInputDict, stepInstance) File "/Users/aalfonsi/projects/raven/ravenframework/Simulation.py", line 842, in executeStep stepInstance.takeAstep(stepInputDict) File "/Users/aalfonsi/projects/raven/ravenframework/Steps/Step.py", line 320, in takeAstep self._localTakeAstepRun(inDictionary) File "/Users/aalfonsi/projects/raven/ravenframework/Steps/MultiRun.py", line 224, in _localTakeAstepRun sampler.finalizeActualSampling(finishedJobList[0],model,inputs) File "/Users/aalfonsi/projects/raven/ravenframework/Samplers/Sampler.py", line 1134, in finalizeActualSampling self.localFinalizeActualSampling(jobObject, model, myInput) File "/Users/aalfonsi/projects/raven/ravenframework/Optimizers/RavenSampled.py", line 325, in localFinalizeActualSampling self._useRealization(info, rlz) File "/Users/aalfonsi/projects/raven/ravenframework/Optimizers/GeneticAlgorithm.py", line 870, in _useRealization childrenXover = self._crossoverInstance(parents=parents, ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/aalfonsi/projects/raven/ravenframework/Optimizers/crossOverOperators/crossovers.py", line 139, in twoPointsCrossover [loc1,loc2] = randomUtils.randomChoice(list(range(1,nGenes)), size=2, replace=False, engine=None) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/Users/aalfonsi/projects/raven/ravenframework/utils/randomUtils.py", line 409, in randomChoice raise RuntimeError("array size < of number of requested samples (size)") RuntimeError: array size < of number of requested samples (size)

This happens when you have only 2 variables to optimize. It is due to line 139 in crossovers.py:
[loc1,loc2] = randomUtils.randomChoice(list(range(1,nGenes)), size=2, replace=False, engine=None)

This list(range(1,nGenes)) returns a list of 1 element when it should return 2?

I guess that line should be modified to
[loc1,loc2] = randomUtils.randomChoice(list(range(0,nGenes)), size=nGenes, replace=False, engine=None)

Steps to Reproduce

just take the MinwoRepMultiObjective.xml test file and convert to 2 variables case.

Expected Behavior

No crash?

Screenshots and Input Files

No response

OS

Linux

OS Version

No response

Dependency Manager

PIP

For Change Control Board: Issue Review

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• If it will impact requirements or requirements tests, is it tagged with requirements?
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• Is a rationale provided? (Such as explaining why the improvement is needed or why current code is wrong.)

For Change Control Board: Issue Closure

• If the issue is a defect, is the defect fixed?
• If the issue is a defect, is the defect tested for in the regression test system? (If not explain why not.)
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• If the issue is a defect, does it impact the latest release branch? If yes, is there any issue tagged with release (create if needed)?
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