| xy.coords {grDevices} | R Documentation |
xy.coords is used by many functions to obtain
x and y coordinates for plotting. The use of this common mechanism
across all relevant R functions produces a measure of consistency.
xy.coords(x, y = NULL, xlab = NULL, ylab = NULL, log = NULL,
recycle = FALSE)
x, y |
the x and y coordinates of a set of points.
Alternatively, a single argument x can be provided. |
xlab,ylab |
names for the x and y variables to be extracted. |
log |
character, "x", "y" or both, as for
plot. Sets negative values to NA and
gives a warning. |
recycle |
logical; if TRUE, recycle (rep)
the shorter of x or y if their lengths differ. |
An attempt is made to interpret the arguments x and y in
a way suitable for bivariate plotting (or other bivariate procedures).
If y is NULL and x is a
yvar ~ xvar. xvar and
yvar are used as x and y variables.x and y, these are
used to define plotting coordinates.time(x) and the y values to be the time series.data.frame with two or more
columns:x
has columns named "x" and "y"; these names will be
irrelevant here.
In any other case, the x argument is coerced to a vector and
returned as y component where the resulting x is just
the index vector 1:n. In this case, the resulting xlab
component is set to "Index".
If x (after transformation as above) inherits from class
"POSIXt" it is coerced to class "POSIXct".
A list with the components
x |
numeric (i.e., "double") vector of abscissa values. |
y |
numeric vector of the same length as x. |
xlab |
character(1) or NULL, the ‘label’ of
x. |
ylab |
character(1) or NULL, the ‘label’ of
y. |
plot.default, lines, points
and lowess are examples of functions which use this mechanism.
xy.coords(stats::fft(c(1:10)), NULL) with(cars, xy.coords(dist ~ speed, NULL)$xlab ) # = "speed" xy.coords(1:3, 1:2, recycle=TRUE) xy.coords(-2:10,NULL, log="y") ##> warning: 3 y values <=0 omitted ..