############################################################# # # # Combining P-Values # # # ############################################################# # # Date pvalues <- c(0.047, 0.028, 0.216, 0.062, 0.129) # # Number of trials k <- length(pvalues) # # Test statistics # ( tippett <- min(pvalues) ) ( stouffer <- sum(qnorm(pvalues)) / sqrt(k) ) ( fisher <- sum(-2 * log(pvalues)) ) # Alternative caculation of Fisher's test statistic ( fisher.2 <- sum(qchisq(1 - pvalues, 2)) ) # # P-values ( pv.tippett <- pbeta(tippett, 1, k) ) ( pv.stouffer <- pnorm(stouffer) ) ( pv.fisher <- 1 - pchisq(fisher, 2*k) )