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Transformation for -ve binomial data

2 messages · Georgina Sarah Humphreys, Ben Bolker

#
Can anyone advise a good transformation for this data below to produce a normalised distribution?

Many thanks,
Georgina

No. of eggs on mosquito gut:
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
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#
Georgina Sarah Humphreys <g.humphreys.1 <at> research.gla.ac.uk> writes:
normalised distribution?
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)
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