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Derivatives of InterpolatingFunctions
Posted:
Oct 19, 1996 4:17 PM


I'm using an InterpolatingFunction to model a set of data that is a function of three variables (range,height,frequency). I need to generate the partial derivatives of this InterpolatingFunction with respect to each of the variables. Unfortunately, version 2.2 of Mathematica appears unable to do this, unless the InterpolatingFunction is a function of only one variable.
My questions are: 1. Has this been fixed in v3.0 of Mathematica? 2. If not, has anyone written a package to address this shortfall?
I know I could approximate the derivative using something along the lines of (f[x+dx,y,z]f[xdx,y,z])/(2dx), but I suspect that this could lead to problems if I make the wrong choice of dx. Does anyone care to comment?
Many thanks,
Paul
__________________________________________________________
Paul E Howland, MEng CEng MIEE Tel +441684895767 Long Range Ground Radar Sensors Fax +441684896315 DRA Malvern Malvern, Worcs, UK __________________________________________________________



