https://github.com/cran/fields
Tip revision: e41cdb90fbcc54695ce1724284e5b3f3abcf643a authored by Doug Nychka on 21 October 2008, 16:58:57 UTC
version 5.01
version 5.01
Tip revision: e41cdb9
radbas.constant.R
# fields, Tools for spatial data
# Copyright 2004-2007, Institute for Mathematics Applied Geosciences
# University Corporation for Atmospheric Research
# Licensed under the GPL -- www.gpl.org/licenses/gpl.html
"radbas.constant" <-
function (m, d)
{
# local gamma function to avoid imprecision warnings for negative arguments.
gamma.local <- function(x){
if( x<0){
temp<- 1
while( x<0){
temp<- temp*x
x<- x+1
}
return(gamma(x)/temp)}
else{
gamma(x)}
}
if (d%%2 == 0) {
Amd <- (((-1)^(1 + m + d/2)) * (2^(1 - 2 * m)) *
(pi^(-d/2)))/(gamma(m) * gamma.local(m - d/2 + 1))
}
else {
Amd <- (gamma.local(d/2 - m) * (2^(-2 * m)) * (pi^(-d/2)))/gamma(m)
}
Amd
}