Re: discrete numerical 2D gradient

*To*: mathgroup at smc.vnet.net*Subject*: [mg113121] Re: discrete numerical 2D gradient*From*: Mark McClure <mcmcclur at unca.edu>*Date*: Wed, 13 Oct 2010 23:26:54 -0400 (EDT)*References*: <201010121749.NAA03478@smc.vnet.net>

On Tue, Oct 12, 2010 at 1:49 PM, Sebastian Schmitt <sschmitt at physi.uni-heidelberg.de> wrote: > I have 2D data represented as a matrix. I would like to obtain the > gradient. > ... > Is there a better (both mathematical and Mathematical) to construct the > y-derivatives (dyMatrix)? I would use ListInterpolation on your dataMatrix. The result is an InterpolatingFunction that you can manipulate in all sorts of ways. dataMatrix = Table[i*j, {i, 10}, {j, 10}]; f = ListInterpolation[dataMatrix, {{0, 1}, {0, 1}}]; grad[x_, y_] = {Derivative[1, 0][f][x, y], Derivative[0, 1][f][x, y]}; VectorPlot[grad[x, y], {x, 0, 1}, {y, 0, 1}] Mark McClure

**References**:**discrete numerical 2D gradient***From:*Sebastian Schmitt <sschmitt@physi.uni-heidelberg.de>