Derivative of InterpolatingFunction
- To: mathgroup at smc.vnet.net
- Subject: [mg59745] Derivative of InterpolatingFunction
- From: pdickof at scf.sk.ca
- Date: Fri, 19 Aug 2005 04:32:33 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
I wish to compute gradients of three-dimensional interpolating functions. The browser entry for InterpolatingFunction claims taking derivatives is possible and does not mention limitations in the dimensionality. My naive attempts based on the example for gradients in the browser entry for D have failed even for two dimensions: data = Table[x^2 Sin[ y], {x, -2., 2.}, {y, -2., 2.}]; approx = ListInterpolation[data, {{-2, 2}, {-2, 2}}]; approxGradient = D[approx[x, y], {{x, y}, 1}] approxGradient[1, 1] Searching this newsgroup, the closest thing I have found is the 1996 post by Paul Abbot (extract below). Have "enhancements for higher dimensions" been incorporated? Peter Dickof +-------------------------- In The Mathematica Journal 4(2):31 the following appears: Partial Derivatives Presently, Mathematica cannot handle partial derivatives of InterpolatingFunctions. The package DInterpolatingFunction.m, provided by Hon Wah Tam (t... at wri.com) and included in the electronic supplement, computes partial derivatives of two-dimensional InterpolatingFunctions. Enhancements for higher dimensions will eventually be incorporated into Mathematica. +----------------------------------