Add option for IDA consistent initial conditions mode

[Steven-Roberts]

Description

As discussed Monday, this adds the option to pick between IDA's two modes for computing consistent initial conditions.

Proposed changes

This add Ida::setConsistentICType(IdaConsistentICType consistent_ic_type) and a corresponding consistent_ic_type JSON property to set the mode. It keeps the bool findConsistent argument to Ida::initializeSimulation, so it is still possible to skip the solve.

Checklist

• All tests pass.
• Code compiles cleanly with flags -Wall -Wpedantic -Wconversion -Wextra.
• The new code follows GridKit™ style guidelines.
• There are unit tests for the new code.
• The new code is documented.
• The feature branch is rebased with respect to the target branch.
• The CHANGELOG.md has been updated to reflect the changes. If this is a minor PR that is part of a larger fix already included in the file, state so.

[nkoukpaizan]

Looks good to me in terms of providing the option to set the initialization type. I am not sure that if addresses the underlying question about steady-state initialization.

[nkoukpaizan]

This works well to make yp consistent with the equations. If I understood @pelesh's plan correctly, the question is whether we can use IdaConsistentICType::Y to solve for inconsistent y while fixing yp=0 (for a system with differential equations that admits a steady state solution).

I tried to use IdaConsistentICType::Y for the Texas test case, unsuccessfully. @Steven-Roberts My understanding was that this would not work, but is it expected to?

[IDAICFailFlag] The linesearch algorithm failed: step too small or too many backtracks.
29: terminate called after throwing an instance of 'AnalysisManager::Sundials::SundialsException'
29:   what():  Method in Ida class failed!

I could be misunderstanding the plans...

[Steven-Roberts]

Yes, I'm seeing the same issue for the Texas case. Can you explain why you don't expect it to work?

It seems a necessary condition for this working is $f_y(y_0, 0)$ is invertible where $f(y, y')$ is the DAE residual function. Perhaps this is not the case.

I'll need to look closer at the logs to understand why it's failing to converge.

[Steven-Roberts]

From debugging the solver, it's seemingly getting stuck in a local minimum rather than a true root. I think a better initial guess is needed to get it to converge.