Many thanks for your most helpful answers.
Tony Lancaster
On 18 November 2010 20:28, David Winsemius <dwinsem...@comcast.net> wrote:
>
> On Nov 18, 2010, at 1:23 PM, Henrique Dallazuanna wrote:
>
> Try this also:
>>
>> x$x - ave(x$x, x$f)
>>
>
> Could also use scale for only its centering capacities:
>
> unlist(
> tapply(fx$x, fx$f, scale, scale=FALSE) # default for center == TRUE
> )
> 11 12 21 22 23
> 1 -1 -2 2 0
>
> ... but looking at the code for ave and for tapply makes me think ave would
> win in a foot race. scale() has other capacities that make its availability
> useful.
>
> --
> David.
>
>
>
>> On Thu, Nov 18, 2010 at 12:02 PM, Lancaster, Anthony <
>> anthony_lancas...@brown.edu> wrote:
>>
>> Hi,
>>> I'd appreciate help with this. I have a data matrix with one column,
>>> called
>>> f in the example below, a factor. I'd like to subtract the means from
>>> each
>>> of
>>> other columns for each level of the factor. That is, in the example, to
>>> go
>>> from the first matrix below to the second. I know SWEEP will take out
>>> means,
>>> but I want to do this for each level of the factor.
>>> f x
>>> 1 2
>>> 1 0
>>> 2 0
>>> 2 4
>>> 2 2
>>>
>>> f xnew
>>> 1 1
>>> 1 -1
>>> 2 -2
>>> 2 2
>>> 2 0
>>> Thanks
>>>
>>> [[alternative HTML version deleted]]
>>>
>>>
> David Winsemius, MD
> West Hartford, CT
>
>
[[alternative HTML version deleted]]
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
