Problem with partial differential equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg23384] Problem with partial differential equations*From*: Max Ulbrich <mulbrich at physik.tu-muenchen.de>*Date*: Fri, 5 May 2000 02:07:17 -0400 (EDT)*Organization*: Rechenzentrum der Max-Planck-Gesellschaft in Garching*Sender*: owner-wri-mathgroup at wolfram.com

Hi, I have a problem with a partial differential equation. I want to solve a diffusion problem in a time-dependent potential. It works with the potential P1, but not with P2. Can someone help me? P1[x_,t_]=2x^2; P2[x_,t_]=2(x+t)^2; Diff=0.2; G[x_]=Exp[-x^2]; solution=n/.First[ NDSolve[{Derivative[0,1][n][x,t]== Diff*Derivative[2,0][n][x,t]+n[x,t]*Derivative[2,0][P1][x,t]+ Derivative[1,0][n][x,t]*Derivative[1,0][P1][x,t],n[x,0]==G[x], n[-3,t]==G[-3],n[3,t]==G[3]},n,{x,-3,3},{t,0,4}, StartingStepSize->0.05]]; Plot3D[solution[x,t],{x,-2,2},{t,0,4}]; Max Ulbrich ulbrich at biochem.mpg.de