xy.coords {base} | R Documentation |
xy.coords
is used by many function to obtain
x and y coordinates for plotting.
The use of this common mechanism across all R functions
produces a measure of consistency.
plot.default
and lowess
are examples of functions
which use this mechanism.
xy.coords(x, y, 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 be provided.
In this case, an attempt is made to interpret the
argument in a way suitable for plotting.
If the argument is a formula yvar ~ xvar , xvar and yvar
are used as x and y variables;
if the argument is a list containing components x and
y , these are used are assumed to define plotting coordinates;
if the argument contains a time series, the x values are
taken to be time and the y values to be the time series;
if the argument is a matrix with two columns, the first
is assumed to contain the x values and the second the
y values; in any other case, the argument is coerced to a vector
and the values plotted against their indices. |
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. |
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 . |
xy.coords(fft(c(1:10)), NULL) data(cars) ; attach(cars) xy.coords(dist ~ speed, NULL)$xlab # = "speed" str(xy.coords(1:3, 1:2, recycle=TRUE)) str(xy.coords(-2:10,NULL, log="y")) ##> warning: 3 y values <=0 omitted ..