scale(x, center=TRUE, scale=TRUE)
x
| a numeric matrix. |
center
|
either a logical value
or a numeric vector of length equal to the
number of columns of x.
|
scale
|
either a logical value
or a numeric vector of length equal to the
number of columns of x.
|
center determines how column
centering is performed.
If center is a numeric vector with length
equal to the number of columns of x, then
each column of x has the corresponding value
from center subtracted from it.
If center is TRUE then centering is
done by subtracting the column means of x
from their corresponding columns and if center
is FALSE, no centering is done.
The value of scale determines how column
scaling is performed (after centering).
If scale is a numeric vector with length
equal to the number of columns of x, then
each column of x is divided by the corresponding
value from scale.
If scale is TRUE then scaling is
done by dividing the (centered) columns of
x by their root-mean-square,
and if scale is FALSE, no scaling is done.
The root-mean-square for a column is obtained by computing the square-root of the sum-of-squares of the non-missing values in the column divided by the number of non-missing values minus one.
sweep which allows centering (and scaling) with
arbitrary statistics.x <- matrix(1:10, nc=2) (centered.x <- scale(x, scale=FALSE)) cov(centered.scaled.x <- scale(x))# all 1