[R] How to draw the graph of f(x,y) = x * y ?

[Paul Smith]

On Tue, Sep 23, 2008 at 6:32 PM, Duncan Murdoch <murdoch at stats.uwo.ca> wrote:
>> The function curve() draws the graph of functions from R to R. Is
>> there some homologous function to curve() to draw functions from R^2
>> to R?
>
> No, you would have to write it yourself.  The basic idea is to use outer()
> to construct a matrix of function evaluations, then plot the matrix using
> persp, contour, image, rgl::persp3d, etc.  There are examples on the
> ?contour man page.

Thanks, Duncan. perps does what I was looking for.

Paul