Re: NDSolve with NIntegrate where Integral is a function of x

*To*: mathgroup at smc.vnet.net*Subject*: [mg127358] Re: NDSolve with NIntegrate where Integral is a function of x*From*: Oliver Ruebenkoenig <ruebenko at wolfram.com>*Date*: Fri, 20 Jul 2012 03:48:32 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net

On Thu, 19 Jul 2012, Nikthecrab wrote: > I am trying to solve a differential equation using NDSolve . It is of the form: > > NDSolve[{y'[x]=f(x)*Integrate[g(x,t),{t,0,infinity}],y[0]=0.04},y[x],{x,0,10}] > > here f is a function of x and g is a function of x and a dummy variable t for integration. > The integral cannot be solved directly in terms of x.So I tried using NIntegrate.But NIntegrate requires x to be a number while NDSolve clearly has to vary x from 0 to 10. Can anyone suggest a suitable solution to this problem? > > Hi, Unfortunately, your code is not valid so here is an only an idea. Make the NIntegrate a function with a NumericQ pattern like so: myFun[x_?NumericQ]:=NIntegrate[...] Oliver