maxima

Dear all,

suppose I have a bi-variate function f(x,y), I want to find the maxima. 
I define x and y vector, and get matrix z=f(x,y). how can I get which 
(x0,y0) makes z become the maxima?

If you have function values as matrix, you may simply use:

which(z==max(z), arr.ind=TRUE)

or you can consider to use an optimization algorithm directly on your 
function, see ?optim or ?nlm.

Hope it helps

Thomas P.