f.log: Determine an optimized offset s and return log10(data+s).

In cwhmisc: Miscellaneous Functions for Math, Plotting, Printing, Statistics, Strings, and Tools

Description

f.log determines a positive offset s for zero values to be used in a subsequent log transformation.

Usage

  f.log(x)

Arguments

x	vector of data.

Value

The transformed values log10(data + s).

Note

The value for the offset s is optimized to render the transformed values of x log-normal

Author(s)

W.Stahel, ETH Zuerich, [e-mail] adapted by: Christian W. Hoffmann <[e-mail]>

Examples

  x <- c(rep(0,20), exp(rnorm(1000,0.05)))
  fx <- f.log(x)
 ## Not run: 
  oldpar <- par(mfrow = c(2, 3))
  plot(x,main="exp(normal)+zeros")
  qqnorm(x)
  T3plot(x)
  plot(fx,main="optimized offset")
  qqnorm(fx)
  T3plot(fx)
  par(oldpar)
 
## End(Not run)

cwhmisc documentation built on May 1, 2019, 7:55 p.m.