This function rounds the number in pretty way.
roundpretty.sub(k, maxdig)number to be rounded pretty
maximum number of digits after the coma
rounded value
When maxdig is larger than 8 and the number is smaller than 0.00001, the number is rounded to 8 numbers after the coma. When the number ist smaller than 0.0001 the maximum numbers after the coma is 7, and so on.
C. Reimann, P. Filzmoser, R.G. Garrett, and R. Dutter: Statistical Data Analysis Explained. Applied Environmental Statistics with R. John Wiley and Sons, Chichester, 2008.