[R] plot curve on surface

[David Winsemius]

On Aug 24, 2012, at 2:34 AM, Michael Meyer wrote:

>
>
> Greetings,
>
> I would like to plot a curve (in color red) on a surface in a 3D plot.
> Say
>
>     x <- as.vector(seq(-1,1,0.2))
>     dim(x) <- c(length(x),1)
>     y <- as.vector(seq(-1,1,0.2))
>     dim(y) <- c(1,length(y))
>
>     z <- x%*%y         # (x_iy_j)
>
>     # 3D plot of z(x,y)=xy:
>     persp(x,y,z)
>
> Now I would like to plot the curve z=z(x,x) in red on this surface.
> How do I do that?
>

persp(x,y,z) -> res
points( trans3d(x, x, x^2, pmat = res), col = "red")
lines(  trans3d(x, x, x^2, pmat = res), col = "red")

-- 

David Winsemius, MD
Alameda, CA, USA