R code for combining p-values using Bailey and Gribskov (1998) method
pfish <- function(p) {
t <- prod(p)
x <- -log(prod(p))
n <- length(p)
v <- c(1:n-1)
a <- t*(x^v)/factorial(v)
pf <- sum(a)
return(pf)
}
pvals <- NA
pf <- function(pl) {
{ if (any(is.na(pl))) { res <- "There was an empty array of p-values"}
else
res <- pfish(pvals) }
return(res)
}Running this inputting a list of pvalues on vector pvals
pvals <- c(0.1,0.01,0.01,0.7,0.3,0.1) pf(pvals)
we get
[1] 0.002148704