0
and sample standard
deviation
1
.
scale(x, center=T, scale=T)
NA
s) are allowed.
TRUE
,
the mean of (the non-missing data in)
each column is subtracted from the column. If
given as a vector of length
ncol(x)
, this vector is used;
i.e.,
center[j]
is subtracted from column
j
. If
FALSE
,
no centering is done.
TRUE
each column (after centering) is divided by
the square root of sum-of-squares (after centering) over
n-1
,
where
n
is the number of non-missing values.
If given as a vector of length
ncol(x)
, column
j
is divided by
scale[j]
. If
FALSE
, no scaling is done.
x
with optional centering and scaling.
scale
takes as an argument
x
(matrix) and returns a similar matrix whose
columns take elements corresponding to the
center
(mean), and
scale
(standard deviation). If
center
and
scale
are not specified, the
default values will be 0 and 1, respectively.
scale(x) #scale to correlation (0 mean, 1 std dev) scale(x, center=apply(x,2,median), scale=FALSE) #remove column medians, do not scale