On Wed, Sep 17, 2008 at 9:46 AM, Jason Grout
<[EMAIL PROTECTED]> wrote:
>
> William Stein wrote:
>> On Wed, Sep 17, 2008 at 8:02 AM, Jason Merrill <[EMAIL PROTECTED]> wrote:
>>> On Sep 17, 2:20 am, Jason Merrill <[EMAIL PROTECTED]> wrote:
>>>> Here's a monkeypatch that makes this work(ish)
>>>>
>>>> from sage.calculus.calculus import SymbolicExpression
>>>> class FormalSymbolicExpression(SymbolicExpression):
>>>> def __init__(self,expr):
>>>> self.expr = expr
>>>> # just delegate everything to the input expression
>>>> for m in dir(expr):
>>>> self.m = m
>>>> def _repr_(self,simplify=False):
>>>> return self.expr._repr_(simplify=False)
>>>> # implement a _latex_ method
>>>>
>>>> SymbolicExpression.formal = lambda self:
>>>> FormalSymbolicExpression(self)
>>>>
>>>> def formal(expr):
>>>> try:
>>>> return expr.formal()
>>>> except AttributeError:
>>>> return expr
>>> Right... so that delegation bit doesn't actually do anything. This
>>> was leading to
>>>
>>> sage: simplify(formal(exp(I*pi)))
>>> e^(pi*I)
>>>
>>> and presumably horrendous amounts of other strangeness. Here's
>>> another try. It doesn't actually inherit from SymbolicExpression
>>> anymore, which will probably cause some difficulty with isinstance
>>> calls, but it's maybe a little closer
>>>
>>> from sage.calculus.calculus import SymbolicExpression
>>> class FormalSymbolicExpression():
>>> def __init__(self,expr):
>>> self.expr = expr
>>>
>>> def __getattr__(self,attrib):
>>> return getattr(self.expr,attrib)
>>>
>>> def __repr__(self,simplify=False):
>>> return self.expr._repr_(simplify=False)
>>>
>>> SymbolicExpression.formal = \
>>> lambda self: FormalSymbolicExpression(self)
>>>
>>> def formal(expr):
>>> try:
>>> return expr.formal()
>>> except AttributeError:
>>> return expr
>>>
>>> And now
>>>
>>> sage: simplify(formal(exp(I*pi)))
>>> -1
>>
>> Jason,
>>
>> Just a heads up -- your code above is going to become pointless when we
>> switch
>> to using Ginac as a backend for symbolic manipulation, since Sage will no
>> longer
>> keep its own expression tree.
>
>
> I looked at your ginac/pynac symbolic stuff last night. It appears that
> you just call a Gex_to_str function (or something like that) to print
> out the expression, which presumably is a ginac thing. Calling latex()
> on any expression just returns \text{printed representation}. If Sage
> will not maintain the expression tree, will it be able to access it to
> print out a latex form?
Yes.
> Does Ginac output latex versions of expressions?
Yes.
William
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