FractionWithFactoredDenominator.smooth_critical_ideal should accept names as strings

[jdemeyer]

Currently, FractionWithFactoredDenominator.smooth_critical_ideal accepts its variable names as symbolic entries. This is really strange, especially since no symbolic computations are done.

This should be deprecated and the variable names should be accepted as strings (or possibly variables from a pre-existing polynomial ring).

This is needed for #10483.

CC: @simon-king-jena @rwst @dkrenn

Component: asymptotic expansions

Author: Simon King, Ralf Stephan

Branch/Commit: u/jdemeyer/fractionwithfactoreddenominator_smooth_critical_ideal_should_accept_names_as_strings @ acfead5

Reviewer: Daniel Krenn

Issue created by migration from https://trac.sagemath.org/ticket/23640

[jdemeyer]

Branch: u/jdemeyer/fractionwithfactoreddenominator_smooth_critical_ideal_should_accept_names_as_strings

[jdemeyer]

Author: Simon King, Ralf Stephan

[jdemeyer]

Commit: acfead5

[jdemeyer]

comment:2

I'm attaching a patch that I'm moving from #10483. One thing which is missing is the deprecation of the existing behaviour.

---

New commits:

acfead5

Trac #23640: deprecate the misuse of symbolic variables as polynomial variable

[jdemeyer]

comment:5

Minor nitpick about:

            # Coerce alpha into L.
            alpha = [L(a) for a in alpha]

Here you are doing a conversion, not a coercion. Either really do a coercion there or fix the comment.

[jdemeyer]

comment:6

It's also not clear why this coercion/conversion should be done only if indets.

[dkrenn]

Reviewer: Daniel Krenn

[dkrenn]

comment:9

Replying to @jdemeyer:

Minor nitpick about:

            # Coerce alpha into L.
            alpha = [L(a) for a in alpha]

Here you are doing a conversion, not a coercion. Either really do a coercion there or fix the comment.

+1 for using .coerce

[dkrenn]

comment:10

Replying to @jdemeyer:

It's also not clear why this coercion/conversion should be done only if indets.

+1 for doing this always.

[dkrenn]

comment:11

            if isinstance(a, str) and a not in K.variable_names():
                indets.append(a)

There should be an error message, if some a is ignored (i.e., when it is not a string and not an existing variable).