Re: Change of function in an ODE

*To*: mathgroup at smc.vnet.net*Subject*: [mg109056] Re: Change of function in an ODE*From*: "Christoph Lhotka" <christoph.lhotka at univie.ac.at>*Date*: Mon, 12 Apr 2010 06:52:21 -0400 (EDT)

hello, there is an straigthforward way to tell Mathematica to replace funtions AND their derivatives in expressions/equations: expr=r^4 R''''[r] + 2 r^3 R'''[r] - r^2 R''[r] + r R'[r] - L^4 r^4 R[r] == 0 expr/.Table[D[R[r]->r^2 Log[r] G[r],{r,i}],{i,0,4}] which you can now try to solve.. christoph