What version of SymPy is this? Aaron Meurer
On Sat, Feb 7, 2015 at 3:22 PM, Sten Sogaard <sten.soga...@gmail.com> wrote: > 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 > > -- > 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. > To view this discussion on the web visit > https://groups.google.com/d/msgid/sympy/26e2175b-3b22-41b7-ad28-0dc94c1960f6%40googlegroups.com > <https://groups.google.com/d/msgid/sympy/26e2175b-3b22-41b7-ad28-0dc94c1960f6%40googlegroups.com?utm_medium=email&utm_source=footer> > . > For more options, visit https://groups.google.com/d/optout. > -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/sympy/CAKgW%3D6K1vz6frh4sQ8FrFULhiBQJtQxwVNgt-BQ4dwiqCOa%3DPA%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
