On 12-03-12 5:45 PM, Michael wrote:
Dear R users,I have been trying to draw the following 3d graphs: The solid region bounded above by the paraboloid z = 9 - x2 - y2 and below by the unit circle in the xy-plane. I wanted to visualize the solid region bounded by those two graphs. I could draw those two 3d graphs separately, but I could not get those two to work in one single plot. Here's my code for the paraboloid: x<- seq(-10, 10, length= 30) y<- x f<- function(x,y) { 9-x^2-y^2 } z<- outer(x, y, f) persp3d(x, y, z, aspect=c(1, 1, 1), col = "lightblue", xlab = "X", ylab = "Y", zlab = "9-x^2-y^2") And my code for the cylinder with the unit circle as the base: z<- matrix(seq(0, 1, len=50), 50, 50) theta<- t(z) x<- cos(theta*2*pi) y<- sin(theta*2*pi) persp3d(x, y, z, col="red",add=T) I wonder if the other R users have encountered similar problems. If someone can help me out, I'll be very appreciative.
I think the graph is working, it's just that the cylinder is really tiny and hard to see. Your z range goes from -190 to 9 in the first graph, but from 0 to 1 in the cylinder. Try using -200*z + 9 in the second plot, and you'll see the cylinder clearly.
Duncan Murdoch ______________________________________________ [email protected] 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.
