Jacobian Analysis: CONVERTD has been dropped since GAMS v.43

[olejandro]

According to the release notes CONVERTD (CONVERT alias) was dropped in GAMS version 43. Therefore selecting CONVERTD as a solver in Veda leads to a GAMS error.

[olejandro]

Selecting CONVERT instead seems to work. However option jacobian appears depreciated.

[olejandro]

Apparently option DumpGDX replaced option jacobian in GAMS version 34, according to the release notes.

In case of jacobian, although a depreciation warning is displayed, all appears to be working, as long as CONVERT is selected.

[Antti-L]

According to the release notes CONVERTD (CONVERT alias) was dropped in GAMS version 43. Therefore selecting CONVERTD as a solver in Veda leads to a GAMS error.

Yes, users may use any GAMS version (v23 or above), and so CONVERTD does not fail for many users, but instead works well. Therefore, no reason whatsoever to drop CONVERTD under VEDA. TIMES works excellently with all those older GAMS versions (model generation performance may even be better with some older GAMS versions).

Selecting CONVERT instead seems to work. However option jacobian appears depreciated.
Apparently option DumpGDX replaced option jacobian in GAMS version 34.

Again, users may use any GAMS version, and so the jacobian option is not deprecated for many users, and the working option file would be good to retain. Option DumpGDX will thus not work at all for many users (me included). I think it is unnecessary to ostracize VEDA users that may use older but perfectly well-working GAMS versions.

[olejandro]

@Antti-L, I agree that it is important to keep this working for users with older GAMS versions.

Release notes state that CONVERTD is an alias for CONVERT. Won't using CONVERT instead of CONVERTD in older version not work?

[olejandro]

In any case, this error message should probably be updated to provide more accurate instructions (i.e. make them GAMS version specific).

[Antti-L]

Release notes state that CONVERTD is an alias for CONVERT. Won't using CONVERT instead of CONVERTD in older version not work?

CONVERTD is not an alias of CONVERT, but a version of CONVERT that passes information from GAMS to CONVERT in core without use of temporary files. It is designed to speed up GAMS to solver communications. CONVERTD also has some options that CONVERT does not support, e.g. the localsolver option to convert GAMS models into the LocalSolver language. If the user would like to use CONVERTD (and not CONVERT), I think it would helpful if VEDA continues to support that. I am sure GAMS users know which solvers their version includes (because reading the documentation is essential), and keeping it in the list would do no harm to users of new GAMS versions.

[olejandro]

Thanks @Antti-L. Tbh, it is new Veda users that I'm most concerned about. I am sure seasoned GAMS and Veda users can find their way arround.

In any case, making the error message more accurate, I believe, would do the trick.