The Art of R Programming

Creating Three-Dimensional Plots

R offers a number of functions to plot data in three dimensions such as persp() and wireframe(), which draw surfaces, and cloud(), which draws three-dimensional scatter plots. Here, we’ll look at a simple example that uses wireframe().

> library(lattice)
> a <- 1:10
> b <- 1:15
> eg <- expand.grid(x=a,y=b)
> eg$z <- eg$x^2 + eg$x * eg$y
> wireframe(z ~ x+y, eg)

First, we load the lattice library. Then the call to expand.grid() creates a data frame, consisting of two columns named x and y, in all possible combinations of the values of the two inputs. Here, a and b had 10 and 15 values, respectively, so the resulting data frame will have 150 rows. (Note that the data frame that is input to wireframe() does not need ...