xy.coords
X,Y Arguments
Description
Converts various types of arguments representing points
in two dimensions to a standard form: numeric x and y vectors.
Usage
xy.coords(x, y = NULL, xlab = NULL, ylab = NULL, log = NULL,
recycle = FALSE)
Arguments
| x |
if y is supplied and is not NULL, a numeric vector or a value that as.numeric(x)
can convert to a numeric vector.
If y is omitted or NULL, a numeric vector, a matrix, a data.frame,
a ts object, or a list containing components named x and y.
|
| y |
if supplied and not NULL, a numeric vector or something that as.numeric(y) can
convert to a numeric vector.
|
| xlab |
a character string. The output xlab and possibly ylab is based on this string.
|
| ylab |
a character string. The output ylab can be based on this string.
|
| log |
A character string: one of "x", "y", or "xy".
- If log contains an "x", then nonpositive entries in the x
component of the output is converted to NA, with a warning.
- If log contains a "y" the same is done for the y component of the output.
|
| recycle |
A logical value. If TRUE and the x and y components of
the outputs would have different lengths, the shorter is repeated to the length of the longer.
If FALSE, the default, an error is given.
|
Details
If the
y argument is omitted or
NULL, the
x and
y
components of the output, and the corresponding labels
xlab and
ylab,
are derived from just the
x argument, based on its class.
|
| data.frame | The first two columns become x and y.
Their column names become xlab and ylab. If there is only one column then y
is that column, x is seq_along(y), xlab is "Index", and ylab is the input xlab. |
|
| list | The components named "x" and "y" become x and y
and the labels are constructed by pasting the input xlab to "$x" and "$y".
It is an error if the list does not contain components named "x" and "y". |
|
| matrix | The first column becomes x and the second y and the
labels come from the names of those columns. If there is only one
column it is treated as a vector. |
|
| complex | The real part of the x argument becomes the output x and
the imaginary part becomes y. The labels are "Re(xlab)" and "Im(xlab)". |
|
| ts | The x component of the output will be time(x) and xlab is "Time"
and the y component of the output will be as.numeric(x), with ylab being
the input xlab. |
|
| vector | as.numeric(x) becomes the y component of the output
and seq_along(x) becomes the x component.
The output xlab will be "Index" and the output ylab will be the input xlab.
|
In any case, the x and y components of the
output will be converted to numeric vectors.
Value
returns a list with four components, the first two representing points in two dimensions.
| x | a numeric vector giving the x coordinates of the points |
| y | a numeric vector giving the y coordinates of the points |
| xlab | a character string giving a label for the x component |
| ylab | a character string or NULL giving a label for the y component |
Examples
xy.coords(41:45, c(81, 83, 87, 91, 97))
xy.coords(ts(41:45, start=2015.75, freq=4))
xy.coords(data.frame(Temp=11:13, NOx=21:23), ylab="The Response")
xy.coords(matrix(11:16, ncol=2, dimnames=list(NULL, c("ColA", "ColB"))))
xy.coords(list(y=11:13, x=21:23, x2=31:33))
xy.coords(exp(1i*seq(0,2*pi,len=5)))
xy.coords(list(x=11:13, y=21:25), recycle=TRUE)
xy.coords(c(1,-2,3), c(-1,2,3), log="xy")