Speed issues with 'inverse_laplace_transform"

[Sten Sogaard]

I am trying to do an inverse laplace transformation of a relative simple filter, but have found that it does not take much before the transformation takes forever.

I wonder if there is something wrong in my configuration.   Windows 7 WinPython-32bit-2.7.6.4

I started to strip out terms in my filter to see when Sympy could compute a result.

When I try just the real filter (last calculation), the memory footprint keeps growing. I stopped it at 2G.

Any ideas

from sympy import *

from sympy.abc import s,t

from datetime import datetime

startTime = datetime.now()

H = 1/(258.0*s + 1100000.)

inverse_laplace_transform(1/s*H,s,t)

print "1) ",datetime.now() - startTime                    #my computer takes 0.3sec

startTime = datetime.now()

H = 1/(0.07071*s**2 + 258.0*s + 1100000.)

inverse_laplace_transform(1/s*H,s,t)

print "2) ",datetime.now() - startTime                    # 55 minutes and still no solution.... Memory usage: 50Meg

startTime = datetime.now()

H = 1/(7.896e-6*s**3 + 0.07071*s**2 + 258.0*s + 1100000.)

inverse_laplace_transform(1/s*H,s,t)

print "3) ",datetime.now() - startTime

#Real filter

startTime = datetime.now()

H = (0.05*s + 1000.0)**2/(2.209e-10*s**4 + 7.896e-6*s**3 + 0.07071*s**2 + 258.0*s + 1100000.)

inverse_laplace_transform(1/s*H,s,t)

print "4) ",datetime.now() - startTime

[Aaron Meurer]

What version of SymPy is this? 

Aaron Meurer

--
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+un...@googlegroups.com.
To post to this group, send email to sy...@googlegroups.com.
Visit this group at http://groups.google.com/group/sympy.
To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/26e2175b-3b22-41b7-ad28-0dc94c1960f6%40googlegroups.com.
For more options, visit https://groups.google.com/d/optout.