Re: changing variables in differential equations

*To*: mathgroup at smc.vnet.net*Subject*: [mg100650] Re: changing variables in differential equations*From*: dh <dh at metrohm.com>*Date*: Wed, 10 Jun 2009 05:34:44 -0400 (EDT)*References*: <h0l48t$opp$1@smc.vnet.net>

Hi Andre, you start out with one independent variable x. Then after the variable transformation you have 2 (u,v)! Therefore, this can not be a regular transformation. Daniel Andre Hautot wrote: > Hello, > Given an ordinary differential equation of order n, H(x,y,y',y'',...)=0 > Given the change of variables : x=x(u,v) and y=y(u,v) > How to calculate (hopefully recursively) y', y'', and so on as functions > of say : u, v', v'' > > In other words how to translate automatically the differential equation > in terms of the new variables ? > Thanks in advance