Timur is this what you are looking for? from Rtips at
http://lark.cc.ukans.edu/~pauljohn/R/statsRus.html#5.42 ---------------------------------- Question: is it possible to shade the 3d surface like a contour plot? i.e. black for large z, white for small z, say Answer: # Create a simple surface f(x,y) = x^2 - y^2 nx <- 21 ny <- 21 x <- seq(-1, 1, length = nx) y <- seq(-1, 1, length = ny) z <- outer(x, y, function(x,y) x^2 - y^2) # Average the values at the corner of each facet # and scale to a value in [0, 1]. We will use this # to select a gray for colouring the facet. hgt <- 0.25 * (z[-nx,-ny] + z[-1,-ny] + z[-nx,-1] + z[-1,-1]) hgt <- (hgt - min(hgt))/ (max(hgt) - min(hgt)) # Plot the surface with the specified facet colours. persp(x, y, z, col = gray(1 - hgt), theta = 35) persp(x, y, z, col = cm.colors(10)[floor(9 * hgt + 1)], theta = 35) (from Ross Ihaka) Regards, Michael Grant --- Timur Elzhov <[EMAIL PROTECTED]> wrote: > On Sun, Jun 01, 2003 at 06:53:55PM +0200, Uwe Ligges > wrote: > > >> but I'd like to persp()' colors behave like in > image() function! > > > That's not easy, because you have to redefine x, y > and z values. > > > > Simple example: > > > > x <- y <- 1:2 > > z <- matrix(1:4, 2) > > image(x, y, z) # OK, quite nice > > > > but > > > > persp(x, y, z) > > > > has only one facet. So the only way is to > calculate the 9 values for x, > > y, and z to get the corners for the 4 facets in > it. > > That's easy for x and y, but can be impossible for > z... > > OK, thank you for answer! > But, I saw that other mathematic frameworks (CERN > ROOT for instance) > can plot 3D surfaces with colors corresponding to > z-value. > Is there way to do this in R (with another > functions/packages)? > It's not necessary to use _one_ color per facet, > yes?.. :) > > > -- > WBR, > Timur. > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
