A few tweaks to MocoExpressionBasedParameterGoal

[nickbianco]

Brief summary of changes

A handful of changes made to some aspects of MocoExpressionBasedParameterGoal that I noticed while using this as a reference for ExpressionBasedFunction. I've also opted to change the property variable_names to simply variables.

Testing I've completed

Ran the existing tests in testMocoGoals.cpp.

Looking for feedback on...

CHANGELOG.md (choose one)

• no need to update because...tweaks to existing goal.

---

This change is 

[AllisonJohn]

Reviewed all commit messages.
Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @nickbianco)

---

OpenSim/Moco/MocoGoal/MocoExpressionBasedParameterGoal.h line 79 at r1 (raw file):

    }

    /** Set the mathematical expression to minimize or constraint. Variable 

constraint -> constrain
Maybe it should say arithmetic instead of mathematical too

[nickbianco]

Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @AllisonJohn)

---

OpenSim/Moco/MocoGoal/MocoExpressionBasedParameterGoal.h line 79 at r1 (raw file):

Previously, AllisonJohn wrote…

constraint -> constrain
Maybe it should say arithmetic instead of mathematical too

Done.

[AllisonJohn]

Reviewed all commit messages.
Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @nickbianco)

---

OpenSim/Moco/MocoGoal/MocoExpressionBasedParameterGoal.cpp line 78 at r2 (raw file):

    } catch (Lepton::Exception& ex) {
        const std::string msg = ex.what();
        std::string undefinedVar = msg.substr(32, msg.size() - 32);

The reason I had the if statement before is that I thought there could be other types of errors that are not for undefined variables? So I think this change could make it seem like there was an undefined variable when there really isn't.

[AllisonJohn]

Reviewable status: 0 of 2 files reviewed, 1 unresolved discussion (waiting on @nickbianco)

---

OpenSim/Moco/MocoGoal/MocoExpressionBasedParameterGoal.cpp line 78 at r2 (raw file):

Previously, AllisonJohn wrote…

The reason I had the if statement before is that I thought there could be other types of errors that are not for undefined variables? So I think this change could make it seem like there was an undefined variable when there really isn't.

oops I didn't mean to approve

[nickbianco]

Reviewable status: 0 of 3 files reviewed, 1 unresolved discussion (waiting on @AllisonJohn)

---

OpenSim/Moco/MocoGoal/MocoExpressionBasedParameterGoal.cpp line 78 at r2 (raw file):

Previously, AllisonJohn wrote…

oops I didn't mean to approve

Ah, good point. I've added it back and also added a similar if-statement to ExpressionBasedFunction while I was at it.

[AllisonJohn]

Reviewed 1 of 2 files at r2, 2 of 2 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @nickbianco)

[nickbianco]

Windows failure is unrelated, merging.

Thanks @AllisonJohn!