[R] subtract the mean from each column
Chuck Cleland
ccleland at optonline.net
Thu Apr 10 19:15:24 CEST 2008
On 4/10/2008 1:03 PM, kayj wrote:
> Hi,
>
> I am new to R an dI need some help
> I have a matrix of real values 100*300 and I would like to calculate the
> mean for each column , then for each entry in a column i need to subtract
> the mean so I will have a matrix where the columns have zero mean. any one
> know how to do that . Thanks
mymat <- matrix(runif(10*4), ncol=4)
colMeans(mymat)
[1] 0.4711083 0.4825977 0.4757448 0.3037873
newmat <- apply(mymat, 2, scale, scale=FALSE, center=TRUE)
colMeans(newmat)
[1] 1.110223e-17 -2.220446e-17 -1.110223e-17 1.110223e-17
?scale
--
Chuck Cleland, Ph.D.
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