[R] z-transform each column of a data.frame

[Martin Batholdy]

great, thank you!


On 20.01.2012, at 18:10, R. Michael Weylandt wrote:

> ? scale
> apply(x, 2, scale)
> 
> Michael
> 
> On Fri, Jan 20, 2012 at 12:04 PM, Martin Batholdy
> <batholdy at googlemail.com> wrote:
>> Hi,
>> 
>> 
>> I am currently trying to z-transform (that is subtracting the mean and divide by the standard deviation) multiple columns of a data.frame at the same time.
>> 
>> 
>> My first approach was:
>> 
>> x <- data.frame(c(0:10), c(10:20))
>> (x - colMeans(x)) / apply(x, 2, sd)
>> 
>> 
>> This is obviously not working.
>> 
>> Is there a convenient way to z-transform each column separately (so in this case, each column represents an independent variable that should be z-transformed)
>> 
>> 
>> thanks!
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