Date: Jan 26, 2013 1:37 AM Author: JCW Subject: Differentiating Interpolation Functions -- "Delaunay" Interpolation Although I can form a partial-derivative function from an ordinary interpolation function with dD[x_,y_]=N@D[f[x,y],x], I cannot figure out how to to anything similar with Interpolation[...,Method->"Delaunay"] from the Obtuse package. Part of the problem **might** be that the Delaunay interpolation function requires it's arguments to be in curly brackets, but I tried to get around that by defining a "helper" function that has ordinary arguments and feeds them to Delaunay in brackets -- no joy. (I'm running Mathematica 7, so I had to download and install the free package from Ingolf Dahl's site.) Any suggestions? -- JCW