R/getPImatrix.R

In safe: Significance Analysis of Function and Expression

getPImatrix <-
function (n = NULL, y.vec = NULL, block.vec = NULL, K, method = "permutation")
{
    if (!is.null(y.vec))
        n <- length(y.vec)
    if (!is.null(block.vec))
        n <- length(block.vec)
    if (length(n) > 1) {
        n <- length(n)
        cat(paste("Warning: n is given as a vector, and is assumed to be",
            n, "\n"))
    }
    Pi <- matrix(NA, K, n)
    Pi[1, ] <- 1:n
    if (substr(method, 1, 9) == "bootstrap") {
        if (is.null(y.vec) & is.null(block.vec)) {
            for (i in 2:K) Pi[i, ] <- sample(1:n, replace = TRUE)
        }
        else if (is.null(block.vec)) {
            unique <- unique(y.vec)
            for (i in 2:K) {
                for (j in 1:length(unique)) {
                  Pi[i, y.vec == unique[j]] <- sample((1:n)[y.vec ==
                    unique[j]], replace = TRUE)
                }
            }
        }
        else {
            pairs <- unique(abs(block.vec))
            for (i in 2:K) {
                for (j in 1:length(pairs)) {
                  sample <- sample(pairs, 1)
                  Pi[i, match(c(pairs[j], -pairs[j]), block.vec)] <- (1:n)[match(c(sample,
                    -sample), block.vec)]
                }
            }
        }
        return(Pi)
    }
    else {
        if (is.null(block.vec))
            for (i in 2:K) Pi[i, ] <- sample(1:n)
        else {
            if (is.numeric(block.vec))
                block.vec <- abs(block.vec)
            unique <- unique(block.vec)
            for (i in 2:K) {
                for (j in 1:length(unique)) {
                  Pi[i, block.vec == unique[j]] <- sample((1:n)[block.vec ==
                    unique[j]])
                }
            }
        }
        return(Pi)
    }
}