
Last chance! 50% off unlimited learning
Sale ends in
BoxCox()
returns a transformation of the input variable using a Box-Cox transformation.
BoxCoxInv()
reverses the transformation.
BoxCox(x, lambda)
BoxCoxInv(x, lambda)
a numeric vector
transformation parameter
a numeric vector of the same length as x.
The Box-Cox transformation is given by
Box, G. E. P. and Cox, D. R. (1964) An analysis of transformations. JRSS B 26 211--246.
Use BoxCoxLambda
or boxcox
in library(MASS)
to find optimal lambda values.
# NOT RUN {
# example by Greg Snow
x <- rlnorm(500, 3, 2)
par(mfrow=c(2,2))
qqnorm(x, main="Lognormal")
qqnorm(BoxCox(x, 1/2), main="BoxCox(lambda=0.5)")
qqnorm(BoxCox(x, 0), main="BoxCox(lambda=0)")
PlotFdist(BoxCox(x, 0))
bx <- BoxCox(x, lambda = BoxCoxLambda(x) )
# }
Run the code above in your browser using DataLab