Documentation update about trigonometric functions (cos, sin) support

[pierre-haessig]

Hello,

Base on the Julia/JuMP forum discussion Can SCIP solve MINLP with trigonometric functions?, SCIP supports nonlinear expressions with trigonometric functions (cos, sin) as of 2024 (clearly stated in SCIP.jl's README).

However, the SCIP 9.1.0 Documentation: Frequently Asked Questions (FAQ) sections says the opposite ("Trigonometric functions are not yet supported by SCIP. "). I guess it's outdated. I didn't find the release announcement (git blame src/scip/expr_trig.h points to changes made in 2020-2021 and scipopt/CSIP#40 states that in 2018 it didn't), but you probably know better.

I don't know if the file doc/inc/faq/faqtext.txt is autogenerated or not. If not, I can submit a PR (I'm asking because last week, on another project, I wasted a PR by editing a autogenerated doc...).

Once the doc is updated (or just having a link to relevant release notes), the following OR Stackexchange question could be edited:

• https://or.stackexchange.com/questions/120/what-global-minlp-solvers-support-trigonometric-functions

[svigerske]

Indeed, this was added in SCIP 8.0.0,

scip/CHANGELOG

Line 947 in 4508ae7

- Added support for expression types sin, cos, and entropy. Added an expression type that stores a SCIP variable.

I can do the edits in the FAQ. Thank you.

[pierre-haessig]

Thanks for the reference. Now I found sin and cos mentioned in:

• SCIP 8.0.0 release notes https://scipopt.org/doc-8.0.0/html/RN80.php (in "Expressions" section)
• in the SCIP 8.0 paper https://optimization-online.org/2021/12/8728/ (in Section 4 SCIP’s New MINLP Framework / 4.1 New Expressions Framework)

[pierre-haessig]

I saw you commented on https://or.stackexchange.com/questions/120/what-global-minlp-solvers-support-trigonometric-functions, thanks.

I also did it on https://stackoverflow.com/questions/77788277/solve-minlp-with-scip, because although it's off topic regarding the question, it contains a well indexed copy of the SCIP FAQ with the outdated statement on trigonometric functions.