pass algorithm argument to custom numeric evalution methods

[burcin]

Custom numeric evaluation functions defined in the _evalf_() method of symbolic functions accept only the parent of the result as an argument. We should expand this to allow passing an argument parameter as well.

---

See comment:7 for testing instructions.

For merging, apply trac_12289-evalf_dictionary_rebase.patch​, trac_12289-add_algorithm-rebase.patch​, and trac_12289-py_float-fix-rebase.patch​.

[burcin]

The evalf_dict branch of Pynac ​available here, with the attached patches applied to the Sage library, allows this:

sage: cot(1/2).n(algorithm='foo')
11.0000000000000
sage: cot(1/2).n()
1.83048772171245

The docstrings for _convert() etc. methods of symbolic expressions need to be updated to reflect these changes.

[benjaminfjones]

I'm doing some testing of these patches along with rebasing #1173. Thanks Burcin!

[benjaminfjones]

I'm trying to rebase the patch trac_12289-evalf_dictionary.patch​ to sage-5.0, but I'm running into a problem with the type of py_funcs.py_float. In the patch py_float has type object (*)(object, object) but in sage-5.0, it has type object (*)(object, PyObject *) I guess because of a pynac change in the meantime.

To be more specific, with this type def for py_float:

cdef public object py_float(object n, object kwds) except +:

I rebuild sage and get:

Error compiling Cython file:
------------------------------------------------------------
...
    py_funcs.py_is_prime = &py_is_prime

    py_funcs.py_integer_from_long = &py_integer_from_long
    py_funcs.py_integer_from_python_obj = &py_integer_from_python_obj
    
    py_funcs.py_float = &py_float
                       ^
------------------------------------------------------------

sage/symbolic/pynac.pyx:2040:24: Cannot assign type 'object (*)(object, object)' to 'object (*)(object, PyObject *)'

Any suggestions (burcin?)

[benjaminfjones]

rebase to sage-5.0 + pynac-0.2.4 spkg

[benjaminfjones]

fix py_float delcaration

[benjaminfjones]

I've been working on this ticket today at sd40.5. I've got burcin's changes working in sage-5.0 with a caveat. Here's how to get the example in comment:1 working in sage-5.0:

1. install the patched pynac-0.2.4.p1 spkg at ​http://sage.math.washington.edu/home/bjones/pynac-0.2.4.p1.spkg. this spkg is the pynac-0.2.4 spkg from #12950 which has been patched to include the changes from burcin's pynac-wip branch of pynac mentioned above.

2. apply all patches at #12950, here is a shell script to help that (run from $SAGE_ROOT/devel/sage): ​http://sage.math.washington.edu/home/bjones/trac_12950_apply.sh

3. apply the patches to $SAGE_ROOT/devel/sage
   • trac_12289-evalf_dictionary_rebase.patch​
   • trac_12289-add_algorithm_arg.patch​
   • trac_12289-example.patch​
   • trac_12289_py_float_fix.patch​ (fixes the problem I had in comment:4)

4. sage -b

[kcrisman]

Patchbot, though, should only apply trac_12289-evalf_dictionary_rebase.patch, trac_12289-add_algorithm_arg.patch, and trac_12289_py_float_fix.patch

[dsm]

So that we don't forget to fix it later:

sage: erf(1).n(algorithm='foo')
0.842700792949715
sage: erf(0)
0
sage: parent(erf(0))
Integer Ring
sage: erf(0).n(algorithm='foo')
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)

/Users/mcneil/sagedev/sage-5.1.beta0b/sage-5.1.beta0/devel/sage-hack2/sage/<ipython console> in <module>()

/Users/mcneil/sagedev/sage-5.1.beta0b/sage-5.1.beta0/local/lib/python2.7/site-packages/sage/structure/element.so in sage.structure.element.Element.numerical_approx (sage/structure/element.c:4988)()

TypeError: numerical_approx() got an unexpected keyword argument 'algorithm'

[kcrisman]

1. install the patched pynac-0.2.4.p1 spkg at ​http://sage.math.washington.edu/home/bjones/pynac-0.2.4.p1.spkg. this spkg is the pynac-0.2.4 spkg from #12950 which has been patched to include the changes from burcin's pynac-wip branch of pynac mentioned above.

Is this stuff in the current Pynac 0.2.6?

2. apply all patches at #12950, here is a shell script to help that (run from $SAGE_ROOT/devel/sage): ​http://sage.math.washington.edu/home/bjones/trac_12950_apply.sh

Can now be skipped, presumably.

3. apply the patches to $SAGE_ROOT/devel/sage
   • trac_12289-evalf_dictionary_rebase.patch​
   • trac_12289-add_algorithm_arg.patch​
   • trac_12289-example.patch​
   • trac_12289_py_float_fix.patch​ (fixes the problem I had in comment:4)

4. sage -b

[kcrisman]

Some of these patches have bitrotted slightly. Updates coming up.

[kcrisman]

Regarding Doug's comment on

erf(0).n(algorithm='foo')

Is this something we want to fix here? I'm not sure whether this is behavior that is supported with this patch, though perhaps it should be. I think that so far this is only putting in infrastructure, right? I don't see any doctests here, for instance.