2 variable index-1 DAE problem proposed by Ascher et al.

ComputationalScienceLaboratory / ODE-Test-Problems

A MATLAB suite of initial value problems

https://computationalsciencelaboratory.github.io/ODE-Test-Problems/

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2 variable index-1 DAE problem proposed by Ascher et al. #5

Closed elswit closed 4 years ago

elswit commented 4 years ago

This DAE is interesting bc it's the only one in OTP with time-dependent mass matrix.

Steven-Roberts commented 4 years ago

I think all the issues have been addressed. I updated Problem and Rhs to support more odeset options and renamed the MassMatrix property of Rhs to Mass for consistency with odeset.

AndreyAPopov commented 4 years ago

Does this address the InitialSlope issue? I know you did some MassSingular stuff.

Steven-Roberts commented 4 years ago

Yeah, InitialSlope isn't necessary if MStateDependence is set.

AndreyAPopov commented 4 years ago

The only problem I see then is operator spacing. In most of the code we have

-1a + 2b + 3*c

instead of

-1 a + 2 b + 3 * c

like the code in this branch now has.

should we prefer one over the other?

Steven-Roberts commented 4 years ago

I'm not that bothered about the multiplication spacing. We would have to change many files to make that consistent.

AndreyAPopov commented 4 years ago

OK. I tend to agree. I don't think there are any more issues then, correct?