ASKSAGE: Sage Q&A Forum - RSS feedhttps://ask.sagemath.org/questions/Q&A Forum for SageenCopyright Sage, 2010. Some rights reserved under creative commons license.Sat, 18 Feb 2017 20:13:43 +0100How can I Integrate the dirac_delta and heaviside functions in sage?https://ask.sagemath.org/question/8041/how-can-i-integrate-the-dirac_delta-and-heaviside-functions-in-sage/Is it possible to integrate the dirac_delta and the heaviside function in sage. I can't seem to do it. For the dirac_delta I've tried the following code:
reset()
var('x,a')
integral(x^2*dirac_delta(-a + x), x, -infinity, +infinity)
from which, after evaluating, I get:
integrate(x^2*dirac_delta(-a + x), x, -Infinity, +Infinity)
i.e. the integration is not performed. I am expecting a^2.
For the heaviside fucntion I've tried:
reset()
var('x,x1,x2')
k(x,x1,x2)=heaviside(x-x1)*heaviside(x2-x)
integrate(k(x,x1,x2),x,-infinity,infinity)
from which, after evaluating, I get:
integrate(heaviside(-x + x2)*heaviside(x - x1), x, -Infinity, +Infinity)
I am expecting x2-x1. Am I doing something wrong or is it just not possible to do these integrations in sage?rtrwalkerThu, 31 Mar 2011 20:56:34 +0200https://ask.sagemath.org/question/8041/How to find inverse laplace transformhttps://ask.sagemath.org/question/36656/how-to-find-inverse-laplace-transform/Hi!
I'm trying to find the inverse laplace transform from the following equation:
(5 * s * e^(-2*s))/(s^2 + 9).inverse_laplace(s,t),
although sage responds with:
ilt((5 * s * e^(-2*s))/(s^2 + 9)).
How do I find the inverse laplace transform from the equation above?
Sincerly SimonismonSat, 18 Feb 2017 20:13:43 +0100https://ask.sagemath.org/question/36656/laplace(heaviside(t),t,s) doesn't return 1/shttps://ask.sagemath.org/question/33152/laplaceheavisidetts-doesnt-return-1s/ var('s')
var('t',domain='positive')
laplace(heaviside(t),t,s)
returns an unevaluated function object in stead of returning `1/s`. Other functions such as `sin(t)` and `dirac_delta(t)` seem to give the correct results. Is this just a blind spot in laplace, or do I need to refine my domains on `s` or `t`?
If this transform just isn't implemented, is there an easy way for me to patch it locally?G BWed, 20 Apr 2016 01:14:14 +0200https://ask.sagemath.org/question/33152/