Fix Jacobian sparsity pattern with observed derivatives #3949
Conversation
hersle
force-pushed
the
jac_observed_derivative
branch
from
4d13c7a to
0dac698
Compare
hersle
force-pushed
the
jac_observed_derivative
branch
from
0dac698 to
16c9c0d
Compare
|
It looks to me like the relevant tests are passing. Do you have any input on this @ChrisRackauckas? |
| sparsity = torn_system_jacobian_sparsity(sys) | ||
| sparsity === nothing || return sparsity | ||
| # disable to fix https://github.com/SciML/ModelingToolkit.jl/issues/3871 | ||
| #sparsity = torn_system_jacobian_sparsity(sys) | ||
| #sparsity === nothing || return sparsity |
There was a problem hiding this comment.
@AayushSabharwal is there a reason the torn sparsity would have false zeros here? That seems like it would give issues in other places.
There was a problem hiding this comment.
I'm not 100% sure, we've just used torn_system_jacobian_sparsity since the beginning of time iirc. Maybe this doesn't handle the W sparsity correctly?
There was a problem hiding this comment.
Well I would think that if this sparsity pattern is wrong, then the incidence matrix is wrong. Can you make a note to follow up on this? For now I want to merge so that these are right, but I'd like to make sure something isn't hiding here.
|
Thanks. I noticed it looks like |
3 participants
I want to fix #3871.
I figured
torn_system_jacobian_sparsitycomputes an incorrect sparsity pattern for this example.My first idea is to disable it and always compute
jacobian_sparsitywith the "fallback method"Symbolics.jacobian_sparsity(...).If this does not work in all cases, the alternative would be to patch
torn_system_jacobian_sparsitydirectly.