Spencer Graves wrote: > > A hemisphere is relatively easy; try the following: > > x <- seq(-1, 1, length=21) > Z <- outer(x, x, function(x, y)sqrt(1-x^2-y^2)) > persp(x=x, y=x, z=Z) > > A contour plot is also relatively easy: > > image(x=x, y=x, z=Z) > contour(x=x, y=x, z=Z, add=T) > > However, if you want an honest perspective plot of a sphere > complete with the underside, etc., I know of nothing in R that could do > that. S-Plus has "perspp", which could be used. However, that seems to > be one of the few features available in S-Plus that is not currently > available in R.
The R package "rgl" by Adler and Nenadic can plot spheres. It is available at http://wsopuppenkiste.wiso.uni-goettingen.de/~dadler/rgl/ --- and looks like it will shortly become a CRAN package. Uwe Ligges > hope this helps. > spencer graves > > Derick Schoonbee wrote: > > > Hi, > > > > I'm new to R (and math ;) Would somebody please be so kind as to > > direct me in plotting a 3D sphere? > > > > I tried something in the lines of: > > #### > > y <- x <- seq(-pi, pi, length=pi*10) > > f <- function(x,y) > > { > > z <- sqrt(pi - x^2 - y^2) > > #z[is.na(z)] <- 0 > > z > > } > > z <- outer(x, y, f) > > > > persp(x, y, z, theta = 120, phi = 30) > > #### > > > > I've also tried: .... make.surface.grid(...) .. persp( as.surface( > > grid, z) ) ... with the same result: 'Incomplete' demi sphere and > > others.. > > > > Any suggestions/solutions would be appreaciated. > > > > Regards, > > Derick > > > > PS:Merry X-mas ;) > > > > ______________________________________________ > > [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 ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help
