#11888: Sage is missing the lambert_w function
----------------------------------------------------------------------------------+
Reporter: benjaminfjones
| Owner: burcin
Type: defect
| Status: needs_work
Priority: minor
| Milestone: sage-5.0
Component: symbolics
| Keywords: lambert_w symbolics conversion maxima sd35.5
Work_issues:
| Upstream: N/A
Reviewer: Keshav Kini, Karl-Dieter Crisman, Fredrik Johansson, Burcin
Erocal | Author: Benjamin Jones
Merged:
| Dependencies: #12507
----------------------------------------------------------------------------------+
Comment(by benjaminfjones):
Replying to [comment:33 burcin]:
>
> You need to define `_maxima_init_evaled_()`. See line 895 of
`sage/fuctions/other.py`:
>
> http://hg.sagemath.org/sage-
main/file/c239be1054e0/sage/functions/other.py#l895
>
It seems that adding `_maxima_init_evaled_()` solves one issue, converting
to Maxima with `_maxima_()`,
{{{
sage: lambert_w(x)._maxima_()
lambert_w(x)
sage: lambert_w(1,x)._maxima_()
...
NotImplementedError: Non-principal branch lambert_w[1](x) is not
implemented in Maxima
}}}
but integration still doesn't work (same error is raised as before).
Looking closer it seems that the issue is here:
{{{
sage: z = lambert_w(x)
sage: z.operands()
[0, x]
sage: z.operator()
lambert_w
}}}
because when `sr_to_max` is called in the integration code, I get:
{{{
sage: from sage.interfaces.maxima_lib import sr_to_max
sage: sr_to_max(lambert_w(x))
<ECL: ((%LAMBERT_W) 0 $X)>
sage: sr_to_max(lambert_w(1, x))
<ECL: ((%LAMBERT_W) 1 $X)>
}}}
and Maxima barfs because it doesn't know what to do with `((%LAMBERT_W) 0
$X)`.
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/11888#comment:34>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sage-trac?hl=en.
