More universal way of writing gradient

*To*: mathgroup at smc.vnet.net*Subject*: [mg112900] More universal way of writing gradient*From*: Sam Takoy <sam.takoy at yahoo.com>*Date*: Tue, 5 Oct 2010 05:35:08 -0400 (EDT)

Hi, My question is not related to the gradient at all, but rather strictly the grammar of Mathematica. Gradient is just an example. My question is: what's the elegant way to write the following function so that it applies to single functions as well as ("rectangular") lists of functions? grad[u_] := {Derivative[1, 0][u], Derivative[0, 1][u]} gradList[u_] := {Map[Derivative[1, 0], u, {2}], Map[Derivative[0, 1], u, {Length[Dimensions[u]]}]} f[x_, y_] := Sin[x] Exp[y] Through[grad[f][x, y]] // MatrixForm gradList[{{f, f}, {f, f}}] // Map[Apply[#, {x, y}] &, #, {Length[Dimensions[#]]}] & // MatrixForm I'm sure I could wrap grad and gradList into a function with an If, but I'm sure there is a more natural way. Thank you in advance, Sam PS: Using Map[Apply[]] in the second case because Through doesn't seem to work with Lists of Lists. This is the subject of an earlier post...