Georgina Sarah Humphreys <g.humphreys.1 <at> research.gla.ac.uk>
writes:
>
> Can anyone advise a good transformation for this data below to produce a
normalised distribution?>
> Many thanks,
> Georgina
>
>
Depending on how "normal" you want it to be, this may be
impossible because about a third of your data set (14/47)
has the same value (1). There's no transformation that
can spread out a peak consisting of identical values.
d <- c(1,12,1,12,6,17,54,1,12,2,22,27,1,27,1,
1,6,24,10,54,12,5,27,68,1,4,6,27,
1,1,1,1,68,1,7,1,10,5,4,1,7,9,3,19,22,10,4)
table(d)
> table(d)
d
1 2 3 4 5 6 7 9 10 12 17 19 22 24 27 54 68
14 1 1 3 2 3 2 1 3 4 1 1 2 1 4 2 2
Naively, the Box-Cox transformation says you should
be using a log transformation (lambda=0)
library(MASS)
boxcox(d~1)
good luck,
Ben Bolker