Incomplete Beta
On Tue, 13 Dec 2005 Ted.Harding at nessie.mcc.ac.uk wrote:
On 13-Dec-05 Thomas Lumley wrote:
On Tue, 13 Dec 2005, Albert Sorribas wrote:
Is there any function available in R for computing the incomplete Beta function?
pbeta(). The incomplete Beta function is the cdf of the Beta distribution
But don't forget to multiply by beta(,):
ibeta(x,a,b) <- function(x,a,b){ pbeta(x,a,b)*beta(a,b) }
!
Depends on which definition you use, as ?pbeta explains. Thomas' advice was correct rather than yours for Abramowitz and Stegun's definition, for example.
Brian D. Ripley, ripley at stats.ox.ac.uk Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595