My phenotype is not normally distributed. I tried several transformations but none of them seems to improve the normality. I am now interested in an inverse normal transformation using R.
Is something like the following correct, x being my phenotype?
qx <- qnorm((rank(x)-0.5)/sum(x))
It is based on this paper:
Yang, Jian, et al. "FTO genotype is associated with phenotypic variability of body mass index." Nature 490.7419 (2012): 267.
Histogram before transformation available here: https://imgur.com/a/BwednJB
More information about the raw data:
- min: 10
- max: 750
- median: 54.75
- mean: 86.18217
- variance: 8428.881
- standard deviation: 91.80894