Re: Convolution Integral

*To*: mathgroup at smc.vnet.net*Subject*: [mg72745] Re: Convolution Integral*From*: Bill Rowe <readnewsciv at sbcglobal.net>*Date*: Wed, 17 Jan 2007 07:08:51 -0500 (EST)

On 1/16/07 at 2:07 AM, senra99 at yahoo.co.uk (Mr Ajit Sen) wrote: >Could anyone please help me with the following? >I'd like to find the convolution of 2 arbitrary >functions, f(t) and g(t) in the Laplace transform sense,i.e., >convolve[f[t],g[t]]=Integrate[f[u]*g[t-u],{u,0,t}] >Thus, I'd like convolve[Sin[t],Exp[-t]] to return >(Exp[-t]-Cos[t]+Sin[t])/2 . >My several attempts with function definitions such as >convolve[f_,g_]:=Integrate[f[u]*g[t-u],{u,0,t}] This definition works fine *if* you supply pure functions as arguments, i.e., In[3]:= convolve[f_,g_]:=Integrate[f[u]g[t-u],{u,0,t}] In[4]:= convolve[Sin[#]&,1/Exp[#]&] Out[4]= (1/2)*(-Cos[t] + E^(-t) + Sin[t]) -- To reply via email subtract one hundred and four