[R] image plot but data not on grid.

[W Eryk Wolski]

Hi,

Would like to make an image
however the values in z are not on an uniform grid.

Have a dataset with
length(x) == length(y) == length(z)
x[1],y[1] gives the position of z[1]

and would like to encode value of z by a color.

looking for something like
plot(x,y, col = z)
where col for z is cleverly chosen from a colorscale.

Hope I made clear what I am looking for.

Thanks
Eryk