[R] negatively skewed data; reflecting
kubovy at virginia.edu
Wed Aug 23 15:11:22 CEST 2006
On Aug 23, 2006, at 8:08 AM, z.dalton at lancaster.ac.uk wrote:
> I have constructed histograms of various variables in my dataset.
> Some of them are negatively skewed, and hence need data
> transformations applied. I know that you first need to reflect the
> negatively skewed data and then apply another transformation such
> as log, square root etc to bring it towards normailty. How is it
> that I reflect data in R?
>> hist(Lsoc) #how do I reflect Lsoc in R?
To reflect the vector Lsoc, assuming the numbers are positive, and
keep them positive in order to take (e.g.) logs,
log(-Lsoc + max(Lsoc) + 1).
But if you do a Google search on 'ladder powers negative skew' you'll
find another answer. The idea of the ladder of powers is due to J W
Professor Michael Kubovy
University of Virginia
Department of Psychology
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