#15074: Allowing 'textbook style' derivative output from pynac
-------------------------------+-------------------------
Reporter: mbejger | Owner:
Type: enhancement | Status: new
Priority: major | Milestone: sage-5.12
Component: symbolics | Resolution:
Keywords: | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
Dependencies: | Stopgaps:
-------------------------------+-------------------------
Comment (by nbruin):
Replying to [comment:4 mbejger]:
> Dear All, I have added a newer patch with an additional switch that
allows for omitting the arguments of a function:
>
> {{{
> var('x y z'); f = function('f', x, y, z)
> f.diff(x,z,y,z)
> D[0, 1, 2, 2](f)(x, y, z)
> from sage.symbolic.pynac import omit_function_args
> omit_function_args(True)
> D[0, 1, 2, 2](f)
> }}}
Not a good idea. How do you tell apart the two following extremely
different objects:
{{{
sage: sage.symbolic.operators.FDerivativeOperator(f,[0,1,2,2])
D[0, 1, 2, 2](f)
sage: f(x,y,z).diff(x,z,y,z)
D[0, 1, 2, 2](f)(x, y, z)
}}}
The standard printing reflects exactly their relation: The second is
obtained by evaluating the first at `(x,y,z)`.
I think having a printing option that does something along the lines of
{{{
if (isinstance(expr.operator(),
sage.symbolic.operators.FDerivativeOperator) and
are_all_distinct_pure_variables(expr.operands())):
return "diff(%s%s,%s)"%(
expr.operator().function(),
tuple(expr.operands()),
tuple( v.operands()[i] for i in v.operator().parameter_set())
else:
return <normal string rep>
}}}
would be reasonable. That's the same approach maple seems to take.
--
Ticket URL: <http://trac.sagemath.org/ticket/15074#comment:5>
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 unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/groups/opt_out.
