2009/8/24 Aaron S. Meurer <asmeu...@gmail.com>
> Oh, ok, you are talking about that one. It returns exp(C1 + x) in the
> separable case, which is default, but I think most of the other applicable
> methods do what you expect, including the "best" hint:
> >>> dsolve(f(x).diff(x) - f(x), f(x), hint='all'){'separable': f(x) ==
> exp(C1 + x), 'separable_Integral': Integral(1/_y, (_y, None, f(x))) == C1 +
> Integral(1, x), 'default': 'separable',
> 'nth_linear_constant_coeff_homogeneous': f(x) == C1*exp(x), '1st_linear':
> f(x) == C1*exp(x), 'best_hint': '1st_linear', '1st_linear_Integral': f(x) ==
> (C1 + Integral(0, x))*exp(-Integral(-1, x)), 'order': 1, 'best': f(x) ==
> C1*exp(x)}
>
> Adding the ability for constantsimp() to recognize exp(C1 + x) == C1*exp(x)
> is a feature that probably should be implemented but I didn't have time to
> do.
>
For n=1 I'm fine with exp(C1 + x), but for n=5 it's really ugly. However,
this is so trivial that it's not of practical use anyway.
Vinzent
>
> Aaron Meurer
> On Aug 24, 2009, at 5:26 AM, Vinzent Steinberg wrote:
>
> 2009/8/21 Aaron S. Meurer <asmeu...@gmail.com>
>
>> On Aug 20, 2009, at 4:20 PM, Vinzent Steinberg wrote:
>> > Don't know whether it makes sense to add this trivial special case.
>> I don't see how that is a special case, but I don't like adding
>> special cases anyway.
>
>
> I just expected for f(x).diff(x, n) = f(x) the solution C1*exp(x), this is
> the special case I meant.
>
> Andy Ray Terrel wrote:
>
>> So I'm +1 with this to be merged in. It is a lot of code and I
>> haven't gone over every line but it is well documented and the tests
>> seem to be covering most of the code.
>
>
> I agree with Andy, I'd prefer checkodesol() to return the error only
> instead of the current tuple, but I'm fine with that too, so I'm also +1.
>
> Ondrej, you're an differential equations expert, please have a look, so we
> can push this in. :)
>
> Vinzent
>
>
>
>
>
> >
>
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