grDevices (version 3.3)

xyz.coords: Extracting Plotting Structures

Description

Utility for obtaining consistent x, y and z coordinates and labels for three dimensional (3D) plots.

Usage

xyz.coords(x, y = NULL, z = NULL,
           xlab = NULL, ylab = NULL, zlab = NULL,
           log = NULL, recycle = FALSE)

Arguments

x, y, z

the x, y and z coordinates of a set of points. Both y and z can be left at NULL. In this case, an attempt is made to interpret x in a way suitable for plotting.

If the argument is a formula zvar ~ xvar + yvar, xvar, yvar and zvar are used as x, y and z variables; if the argument is a list containing components x, y and z, these are assumed to define plotting coordinates; if the argument is a matrix or data.frame with three or more columns, the first is assumed to contain the x values, the 2nd the y ones, and the 3rd the z ones -- independently of any column names that x may have.

Alternatively two arguments x and y can be provided (leaving z = NULL). One may be real, the other complex; in any other case, the arguments are coerced to vectors and the values plotted against their indices.

xlab, ylab, zlab

names for the x, y and z variables to be extracted.

log

character, "x", "y", "z" or combinations. Sets negative values to NA and gives a warning.

recycle

logical; if TRUE, recycle (rep) the shorter ones of x, y or z if their lengths differ.

Value

• A list with the components
• x
  numeric (i.e., double) vector of abscissa values.
• y
  numeric vector of the same length as x.
• z
  numeric vector of the same length as x.
• xlab
  character(1) or NULL, the axis label of x.
• ylab
  character(1) or NULL, the axis label of y.
• zlab
  character(1) or NULL, the axis label of z.

See Also

xy.coords for 2D.

Examples

xyz.coords(data.frame(10*1:9, -4), y = NULL, z = NULL)

xyz.coords(1:5, stats::fft(1:5), z = NULL, xlab = "X", ylab = "Y")

y <- 2 * (x2 <- 10 + (x1 <- 1:10))
xyz.coords(y ~ x1 + x2, y = NULL, z = NULL)

xyz.coords(data.frame(x = -1:9, y = 2:12, z = 3:13), y = NULL, z = NULL,
           log = "xy")
##> Warning message: 2 x values <= 0 omitted ...