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 Author Comment/Response Gunnar 07/30/08 08:05am Dear Mathematica specialists, I have written a function to calculate the Poisson equation, namely a differential equation. It works well, and I can plot the result. The next step would be to integrate a function containing this result, and this does not work... can someone help me ? Hereafter I describe the problem in detail: First I define rho=1 chargetest[z_,s_]:=Which[z<=0,0,z>0 && z<=s, rho,z>s,0] Then I define my function plotPotential[fcharge_,rho_,epsilon_,s_,w_,h_,lg_,ld_]:=Module[ {resultat,poisson,potentiel,p1,p2},poisson=potentiel''[z]+fcharge[z,s]/epsilon==0; resultat=potentiel[z]/.DSolve[{poisson,potentiel[-w]==0,potentiel[h]==0},{potentiel[z]},z]; p2=Plot[resultat,{z,lg,ld} ] I can call it with CalculatePotential[chargetest,1,1,10,1000,100,-100,100] and it works, plotting the result. My problem is that I now want to replace the Plot function above by norma=NIntegrate[resultat*Exp[-(h-z)/20],{z,0,h}]; Print[norma] ... and I get an "integrand not numerical" error message. And this I do not understand: I can plot but not calculate with it ?? Thanks very much in advance Gunnar URL: ,

 Subject (listing for 'Problem with NIntegrate') Author Date Posted Problem with NIntegrate Gunnar 07/30/08 08:05am Re: Problem with NIntegrate Xavier 07/31/08 00:21am Re: Re: Problem with NIntegrate Gunnar 07/31/08 07:03am Re: Problem with NIntegrate Xavier 07/31/08 12:28pm
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