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laplace transform cannot handle derivatives?

Open cbm755 opened this issue 10 years ago • 4 comments

If that's true, there must be an upstream issue, or is it a matter of making some assumptions?

cbm755 avatar Dec 11 '14 17:12 cbm755

I think that it should be labelled as upstream: see https://github.com/sympy/sympy/issues/7219

maprieto avatar Dec 17 '14 17:12 maprieto

Thanks @maprieto. So if anyone wants to try to fix this, it should probably be done upstream in SymPy.

cbm755 avatar Dec 17 '14 22:12 cbm755

The same pissue has been detected in the fourier function. A xtest has been included to illustrate it.

maprieto avatar May 18 '15 18:05 maprieto

a report over on Stackoverflow mentioned an error attempting a laplace transform with a derivative (that worked with the derivative removed). Is the error below the same issue reported in this thread tied to the sympy limitation? from that report it seems like the derivative issue would have been fixed in sympy 1.10 and i'm getting the below error in symbolic 3.1.1 with sympy 1.10.1

>> pkg load symbolic
>> syms t s y(t) Y
Symbolic pkg v3.1.1: Python communication link active, SymPy v1.10.1.
>> dy = diff(y(t), t)
dy = (sym)

  d
  --(y(t))
  dt

>> edo = dy + 4*y(t)
edo = (sym)

           d
  4*y(t) + --(y(t))
           dt

>> edotrans = laplace(edo, t, s)
error: Python exception: TypeError: 'Add' object is not subscriptable
    occurred at line 6 of the Python code block:
    return F[0],
error: called from
    pycall_sympy__ at line 179 column 7
    laplace at line 161 column 7

NRJank avatar Nov 20 '23 15:11 NRJank