perspdepth {depth} | R Documentation |
Draws a perspective plot of the surface of a depth function over the x-y plane.
perspdepth(x, method = "Tukey", output = FALSE, tt = 50, xlab = "X", ylab = "Y", zlab = NULL, col = NULL, ...)
x |
Bivariate data as a matrix, data frame or list. If it is a matrix or data frame, then each row is viewed as one bivariate observation. If it is a list, both components must be numerical vectors of equal length (coordinates of observations). |
method |
Character string which determines the depth function used. method can be "Tukey" (the default), "Liu" or "Oja". |
output |
Logical. Default FALSE produces a perspective plot; otherwise, returns a list containing the grid points and depth values over these points. |
tt |
Gridsize. Number of equally spaced grid points in each coordinate direction to be used in perspective plot. |
xlab |
Title for x-axis. Must be a character string. |
ylab |
Title for y-axis. Must be a character string. |
zlab |
Title for z-axis. Must be a character string. Default NULL identifies the depth function. |
col |
Color of the surface plot. Default NULL is "lightblue". |
... |
Any additional graphical parameters. |
Requires the rgl
package. The perspective plot takes advantage of some of the user interaction facilities of that package.
Default output = FALSE
yields a perspective plot; otherwise the function returns a list with components
x |
x-coordinates of the grid where the depth function is evaluated. |
y |
y-coordinates of the grid where the depth function is evaluated. |
z |
Matrix whose entry z[i ,j] is the value of the depth function at (x[i], y[j]). |
Jean-Claude Masse and Jean-Francois Plante, based on Fortran code by Rousseeuw, Ruts and Struyf from University of Antwerp.
Rousseuw, P.J. and Ruts, I. (1996), AS 307 : Bivariate location depth, Appl. Stat.-J. Roy. S. C, 45, 516–526.
## 2 perspective plots data(geyser, package = "MASS") perspdepth(geyser, col = "magenta") open3d() set.seed(159); library(MASS) mu1 <- c(0,0); mu2 <- c(6,0); sigma <- matrix(c(1,0,0,1), nc = 2) mixbivnorm <- rbind(mvrnorm(80, mu1, sigma),mvrnorm(20, mu2, sigma)) perspdepth(mixbivnorm, col = "chartreuse") ## grid coordinates and corresponding depth values set.seed(601) x <- matrix(rnorm(48), nc = 2) perspdepth(x, output = TRUE, tt = 10)