On Thu, Jun 09, 2011 at 11:22:54AM +0200, Uwe Ligges wrote: > Well, > > persp(x, y, z) does exactly what you asked for: it plots tha matrix > z along the values given by the vectors x and y.
But I don't have these vectors x and y, so I have to create them just to call persp(). And persp also needs the values only to rise. But if I have x and y, and I want to have only rising numbers for x and y,m I need somehow to create those values, and expand.grid() would not create value combinations that are only rising. (Or did I miss an option for expand.grid, which does that?) > If you need to calculate z values from x and y using some function > foo, outer(x, y, foo) is typically your friend. OK. And what, if I want to generate the mathcing x- and y- values for a matrix, that has x- and y implicitly, but I only have the z-values inside the matrix? So, my problem is the other way around. I don't want to calc the z for my x-and y, I want to generate the x- and y- values for my matrix of z-values. Ciao, Oliver ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
