Re: Wierdness with the laplacian
- To: mathgroup at smc.vnet.net
- Subject: [mg45152] Re: [mg45132] Wierdness with the laplacian
- From: Hugh Walker <hwalker at gvtc.com>
- Date: Thu, 18 Dec 2003 06:55:28 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
On Wednesday, December 17, 2003, at 06:54 AM, Peter Jay Salzman wrote: > Hi all, > > When I do: > > <<Calculus`VectorAnalysis` > SetCoordinates[Spherical[r, theta, phi] > Laplacian[ Exp[r^2] ] > > Mathematica gives: > > 2 2 > r 2 r 4 > Csc[theta] (6 E r Sin[theta] + 4 E r Sin[theta]) > ------------------------------------------------------ > 2 > r > > Which is wrong since Exp[r^2] is not a function of theta or phi. > > > Why is Mathematica giving this result? > > Thanks! > Pete But it is not wrong. Try Laplacian[ Exp[r^2] ]//Simplify It is, perhaps, a little surprising that Mathematica does not see fit to simplify automatically. ========== Hugh Walker Gnarly Oaks