scale | R Documentation |
scale
centers and/or scales the columns of a FlashR matrix.
## S4 method for signature 'fm' scale(x, center = TRUE, scale = TRUE)
x |
a FlashR matrix |
center |
either a logical value or a numeric vector of length equal to
the number of columns of |
sclae |
either a logical value or a numeric vector of length equal to
the number of columns of |
The value of 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
(omitting NA
s) 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 standard deviations if center
is TRUE
,
and the root mean square otherwise. If scale
is FALSE
,
no scaling is done.
The root-mean-square for a (possibly centered) column is defined
as sqrt(sum(x^2)/(n-1)), where x is a vector of the non-missing
values and n is the number of non-missing values. In the case
center = TRUE
, this is the same as the standard deviation, but
in general it is not.
a FlashR matrix.
Da Zheng <dzheng5@jhu.edu>
mat <- fm.runif.matrix(100, 10) mat <- scale(mat)