>On Sun, Jul 5, 2015 at 10:08 AM, Doug Stewart <
address@hidden> wrote:
>
>On Sat, Jul 4, 2015 at 7:24 PM, Barrett Urness <
address@hidden> wrote:
>>
>> Has anyone had success being able to use laplace transforms using the symbolic 2.2.2 package? I have been able to use the syms function and fourier, but not laplace, this is the error i receive:
>>
>>
>
>This works for me:
>syms t
>f = t^2;
>laplace(f)
what Doug wrote also works for me, but I can get the syms package, or at least Python, to crash out by sending it some laplace fn that gives it trouble. An easy one is to define multiple variables, and not tell it which is the laplace variable. I.e.:
>> syms P
OctSymPy v2.2.2: this is free software without warranty, see source.
Initializing communication with SymPy using a popen2() pipe.
Detected Windows: using "winwrapy.bat" to workaround Octave bug #43036
Some output from the Python subprocess (pid 13480) might appear next.
OctSymPy: Communication established. SymPy v0.7.6.
Python 2.7.9 (default, Dec 10 2014, 12:24:55) [MSC v.1500 32 bit (Intel)]
>> syms R
>> f = exp(R*P)
f = (sym)
P*R
e
>> laplace(f)
PYTHON: Error in cmd
Resetting the octsympy communication mechanism
Closing the Python pipe...
error: python_cmd: unexpected return
Running a laplace on an exponential with one variable yields the expected result. Only having both variables breaks it. I noticed this is the case even if you specify the laplace variable, i.e.,
>>laplace(exp(R*P),P,s)
the above works with either exp(R) or exp(P), but not exp(R*P)
NOTE: I'm running the windows build of 4.0.0 on Windows 7. I have the 'bundled' symbolic installed with the versions as shown above.
Nick Jankowski