A related issue:
In [6]: m = Matrix([[0, theta], [-theta, 0]])
In [7]: exp(m)
Out[7]:
[ I*theta -I*theta I*theta -I*theta]
[ e e I*e I*e ]
[ -------- + --------- - ---------- + -----------]
[ 2 2 2 2 ]
[ ]
[ I*theta -I*theta I*theta -I*theta ]
[I*e I*e e e ]
[---------- - ----------- -------- + --------- ]
[ 2 2 2 2 ]
In [8]: simplify(exp(m))
Out[8]:
[ / 2*I*theta \ -I*theta]
[ I*\- e + 1/*e ]
[cos(theta) ------------------------------]
[ 2 ]
[ ]
[-sin(theta) cos(theta) ]
On Sunday, 13 March 2016 18:14:16 UTC+1, Greg Grunberg wrote:
>
> I'm new to SymPy and this group. My apologies if I'm submitting this to
> the wrong group. Please feel free to indicate a more appropriate alternate
> group, if there is such.
>
> I ran into a behavior of the *simplify* function which strikes me as
> strange. Notice that *in[4]* and *in[5]* below are identical, except
> that the expression to be simplified in the latter is the negative of the
> former. *out[4]* is what I expected, but *out[5]* is not. Shouldn't
> *out[5]* be the negative of *out[4]*? Can anyone explain? Note that
> *out[5]* is not mathematically incorrect but just not what one would
> expect.
>
>
> Python 3.5.1 |Anaconda 2.5.0 (64-bit)| (default, Jan 29 2016, 15:01:46)
> [MSC v.1900 64 bit (AMD64)]
> Type "copyright", "credits" or "license" for more information.
>
> IPython 4.0.3 -- An enhanced Interactive Python.
> ? -> Introduction and overview of IPython's features.
> %quickref -> Quick reference.
> help -> Python's own help system.
> object? -> Details about 'object', use 'object??' for extra details.
>
> In [1]: from sympy import *
>
> In [2]: init_session()
> IPython console for SymPy 1.0 (Python 3.5.1-64-bit) (ground types: python)
>
> These commands were executed:
> >>> from __future__ import division
> >>> from sympy import *
> >>> x, y, z, t = symbols('x y z t')
> >>> k, m, n = symbols('k m n', integer=True)
> >>> f, g, h = symbols('f g h', cls=Function)
> >>> init_printing()
>
> Documentation can be found at http://docs.sympy.org/1.0/
>
> In [3]: theta = symbols('theta', real=True)
>
> In [4]: simplify(+I/2*exp(I*theta) - I/2*exp(-I*theta))
> Out[4]: -sin(theta)
>
> In [5]: simplify(-I/2*exp(I*theta) + I/2*exp(-I*theta))
> Out[5]:
> / 2*I*theta \ -I*theta
> I*\- e + 1/*e
> ------------------------------
> 2
>
>
> 
>
--
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 [email protected].
To post to this group, send email to [email protected].
Visit this group at https://groups.google.com/group/sympy.
To view this discussion on the web visit
https://groups.google.com/d/msgid/sympy/7b314244-e00e-4f51-992c-e253edb07127%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
