I bisected it to

commit cfad6db7172906255c26c3a082257f639bb7107c
Author: Mateusz Paprocki <matt...@gmail.com>
Date:   Thu Mar 21 17:24:57 2013 +0100

    polys: Renamed to RealDomain to RealField.

So one thing not mentioned in the release notes was that there were
some changes to the way the polys handle floating point coefficients.

Another thing not mentioned was the improvements to the ODE module
from Manoj Kumar's GSoC project.

By the way, the workaround here is to pass simplify=False:

>>> dsolve(Eq(Derivative(f(t), t), 1.0), f(t), simplify=False)
f(t) = C₁ + 1.0⋅t

Aaron Meurer

On Wed, Dec 11, 2013 at 9:21 AM, Ondřej Čertík <ondrej.cer...@gmail.com> wrote:
> On Wed, Dec 11, 2013 at 8:08 AM, Marcel Stimberg
> <marcel.stimb...@gmail.com> wrote:
>> Hi everyone,
>>
>> after updating sympy to 0.7.4, some of our code calling dsolve seems to go
>> into an infinite recursion and errors out with "maximum recursion depth
>> exceeded". A simple example demonstrating the issue is the following:
>>
>>>>> f = Function('f')
>>>>> t = Symbol('t')
>>>>> dsolve(Eq(Derivative(f(t), t), 1.0), f(t))
>>
>> In 0.7.3, this yields
>> f(t) == C1 + 1.0*t
>> but in 0.7.4 it goes into the infinite recursion. The issue seems to have to
>> do with the floating point constant, replacing it with an integer number for
>> example makes everything work.
>>
>> Is there something wrong in my use of dsolve or is it a genuine bug in
>> 0.7.4?
>
> This looks like a bug.
>
> In general, you should only use floating point numbers if you really
> need floating point.
> Otherwise it's better to get exact results from sympy by using
> integers or symbols.
> But it should work with floating point too --- thanks for reporting it.
>
> If you want, you can use git bisect to figure out which commit broke it.
>
> Ondrej
>
>>
>> Thanks in advance, best
>>   Marcel
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "sympy" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to sympy+unsubscr...@googlegroups.com.
>> To post to this group, send email to sympy@googlegroups.com.
>> Visit this group at http://groups.google.com/group/sympy.
>> For more options, visit https://groups.google.com/groups/opt_out.
>
> --
> You received this message because you are subscribed to the Google Groups 
> "sympy" group.
> To unsubscribe from this group and stop receiving emails from it, send an 
> email to sympy+unsubscr...@googlegroups.com.
> To post to this group, send email to sympy@googlegroups.com.
> Visit this group at http://groups.google.com/group/sympy.
> For more options, visit https://groups.google.com/groups/opt_out.

-- 
You received this message because you are subscribed to the Google Groups 
"sympy" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to sympy+unsubscr...@googlegroups.com.
To post to this group, send email to sympy@googlegroups.com.
Visit this group at http://groups.google.com/group/sympy.
For more options, visit https://groups.google.com/groups/opt_out.

Reply via email to