Function for pairwise correlations across a data frame

cor.test.R

# E.g. qDat.corr <- as.data.frame(cor.test.p(x))

cor.test.p <- function(x){
  FUN <- function(x, y) cor.test(x, y)[["p.value"]]
  z <- outer(
    colnames(x), 
    colnames(x), 
    Vectorize(function(i,j) FUN(x[,i], x[,j]))
  )
  dimnames(z) <- list(colnames(x), colnames(x))
  z
}