Hi jtaylor74,
On Mon, Feb 9, 2009 at 6:43 PM, jtaylor74 <jetaylo...@gmail.com> wrote:
>
> I don't know if this is a bug or not, but what I want is to evaluate a
> lambdify'ed expression at a numpy.ndarray of points.
>
> Python 2.5.2 (r252:60911, Jul 31 2008, 17:28:52)
> [GCC 4.2.3 (Ubuntu 4.2.3-2ubuntu7)] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import numpy as np
>>>> from sympy import Symbol, Piecewise, lambdify
>>>>
>>>> t=Symbol('t')
>>>> f=Piecewise((0, t<3), (t,(t<4)), (1,t>=4))
>>>> fl = lambdify(t, f)
>>>>
>>>> print [fl(float(_t)) for _t in np.linspace(0,10,11)]
> [0, 0, 0, 3.00000000000000, 1, 1, 1, 1, 1, 1, 1]
>>>> print [fl(_t) for _t in np.linspace(0,10,11)]
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> File "<string>", line 1, in <lambda>
> File "/home/jtaylo/code/virtualenv/nipy/lib/python2.5/site-packages/
> sympy-0.6.3-py2.5.egg/sympy/functions/elementary/piecewise.py", line
> 69, in __new__
> " Relational or Number" % (ec[1], cond_type)
> TypeError: Cond True is of type <type 'numpy.bool_'>, but must be a
> bool, Relational or Number
>>>>
>>>> import numpy.version
>>>> print numpy.version.version
> 1.2.0
>
>>>> import sympy
>>>> print sympy.__version__
> 0.6.3
>>>>
I can reproduce it with the latest git version:
In [1]: import numpy as np
In [2]: t=Symbol('t')
In [3]: f=Piecewise((0, t<3), (t,(t<4)), (1,t>=4))
In [4]: fl = lambdify(t, f)
In [5]: print [fl(float(_t)) for _t in np.linspace(0,10,11)]
[0, 0, 0, 3.00000000000000, 1, 1, 1, 1, 1, 1, 1]
In [6]: print [fl(_t) for _t in np.linspace(0,10,11)]
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
/home/ondra/repos/sympy/<ipython console> in <module>()
/home/ondra/repos/sympy/<string> in <lambda>(t)
/home/ondra/repos/sympy/sympy/functions/elementary/piecewise.pyc in
__new__(cls, *args, **options)
69 raise TypeError, \
70 "Cond %s is of type %s, but must be a bool," \
---> 71 " Relational or Number" % (ec[1], cond_type)
72
73 # sympify args
TypeError: Cond True is of type <type 'numpy.bool_'>, but must be a
bool, Relational or Number
So I think it's a bug. Thanks a lot for reporting it. The problem is
with this code:
if not (cond_type is bool or issubclass(cond_type, Relational) or \
issubclass(cond_type, Number)):
raise TypeError, \
"Cond %s is of type %s, but must be a bool," \
" Relational or Number" % (ec[1], cond_type)
It checks for bool, but not numpy.bool_. Does anyone know how to make
it, so that it works with numpy types, but doesn't use numpy.bool_
explicitely?
Ondrej
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"sympy" group.
To post to this group, send email to sympy@googlegroups.com
To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com
For more options, visit this group at http://groups.google.com/group/sympy?hl=en
-~----------~----~----~----~------~----~------~--~---
