Re: problem with DSolve and spheroidal harmonics

*To*: mathgroup at smc.vnet.net*Subject*: [mg128313] Re: problem with DSolve and spheroidal harmonics*From*: Tom Dickens <tomdickens at att.net>*Date*: Sat, 6 Oct 2012 01:50:52 -0400 (EDT)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com*Delivered-to*: l-mathgroup@wolfram.com*Delivered-to*: mathgroup-newout@smc.vnet.net*Delivered-to*: mathgroup-newsend@smc.vnet.net*References*: <k4lvck$d2q$1@smc.vnet.net>

Thanks to Bob Hanlon who pointed out my misprint: I had " m^2 - " instead of the correct "m^2 / " . THis happened because I have a homebrew code that I use to modify clipboard contents so I can use them for file names, and it changed the "/" to "-". Tom On Fri, 5 Oct 2012 06:40:20 +0000 (UTC), Tom Dickens <tomdickens at att.net> wrote: >All, > >I wonder if this is a bug. I'm working on a project involving >spheroidal harmonics, and tried the following example from the Help: > >DSolve[(1 - x^2) y''[x] - 2 x y'[x] + (SpheroidalEigenvalue[n, m, c] >+ c^2 (1 - x^2) - m^2-( 1 - x^2)) y[x] == 0, y, x] > > {{y -> Function[{x}, C[1] SpheroidalPS[n, m, c, x] + C[2] >SpheroidalQS[n, m, c, x]]}} > >This shows (in the Help) that the defining differential equation is >solved correctly. However, when I run it in either v7 or v8 I get a >differential root object > >{{y->DifferentialRoot[Function[{-[FormalY],-[FormalX]},{-[FormalY][-[FormalX]] >(1--[FormalX]^2-c^2+-[FormalX]^2 >c^2+m^2-SpheroidalEigenvalue[n,m,c])+2 -[FormalX] >(-[FormalY]^-[Prime])[-[FormalX]]+(-1+-[FormalX]^2) >(-[FormalY]^-[Prime]-[Prime])[-[FormalX]]==0,-[FormalY][0]==C[1],(-[FormalY]^-[Prime])[0]==C[2]}]]}} > >Any thoughts? > >Thanks, >Tom