Changing solution when using sparsity pattern with ode15s

Hi everyone,

I have a short question concering the numerics of ode15s. I'm unsure if I can expect excatly the same results when I use the solver with and without the sparsity pattern option. So does enyone know if the solver performs different operations (when applying the sparsity command), which might lead to a small deviation in the result? Thanks a lot!

Best regards

Carsten

Answer 1

[Rollin Baker]

Hi Carsten,

I'm not totally sure if I understand your workflow, but I found a documentation page that details how MATLAB solves non-linear equations using a Jacobian Sparsity Pattern.

https://www.mathworks.com/help/optim/ug/nonlinear-equations-with-jacobian-sparsity-pattern.html

If I understand the page correctly, it seems like you may get a different result, but that is somewhat expected when you change solver configurations. I hope this was relevant to you. Good luck!

[Carsten Asmanoglo]

Hi Rollin,

thank you for your answer. I also found the page you quoted, but for me it does not become 100% clear weather the solution is changed or not by applying the sparsity pattern. Regarding your second point I disagree, the soultion can change but does not need to change if you change the solver options, that depends on the numerics of the solver.