xyz.coords {grDevices}  R Documentation 
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, setLab = TRUE)
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.

setLab 
logical indicating if the resulting xlab and
ylab should be constructed from the “kind” of (x,y) ;
otherwise, the arguments xlab and ylab are used.

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 .

Author(s)
Uwe Ligges and Martin Maechler
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 ...
[Package
grDevices version 4.1.0
Index]