Re: Question about changing variables in PDEs
- To: mathgroup at yoda.physics.unc.edu
- Subject: Re: Question about changing variables in PDEs
- From: withoff
- Date: Sat, 31 Oct 92 10:13:23 CST
----------------- > I have a system of PDE's in in three dependent and two independent > variables. For example: > { Dt[f,x] + f Dt[g,t] - f g, Dt[f,x,t] - Dt[h,x]^2, Dt[g,x] + Dt[h,t]} > In[1]:= d = Dt[f,x] + Dt[g,x] > Out[1]= Dt[f, x] + Dt[g, x] > In[2]:= d /. Dt[y_,x] -> Dt[y,r] > Out[2]= Dt[f, x] + Dt[g, x] --------------------------- Try using Literal: In[6]:= d = Dt[f,x] + Dt[g,x] Out[6]= Dt[f, x] + Dt[g, x] In[7]:= d /. Literal[Dt[y_,x]] -> Dt[y,r] Out[7]= Dt[f, r] + Dt[g, r] Dave Withoff withoff at wri.com