comp2 function

Ties function: bivariate

This function computes the distinct observations (couples) and their frequencies in a bivariate numeric vector.

comp2(y, z)

Details

For internal use.

Examples

## The function is currently defined as
function(y, z) {
  if (length(y) != length(z)) {
    stop("Vectors y and z should have equal length!")
  }
  n <- length(y)
  matY <- outer(y, y, "==")
  matZ <- outer(z, z, "==")
  mat <- matY & matZ
  jstar <- led <- rep(FALSE, n)
  for (j in seq(n)) {
    if (!led[j]) {
      jstar[j] <- TRUE
      if (j == n) {
        break
      }
      ji <- seq(j + 1, n)
      tt <- mat[ji, j] %in% TRUE
      led[ji] <- led[ji] | tt
    }
    if (all(led[-seq(j)])) {
      break
    }
  }
  ystar <- y[jstar]
  zstar <- z[jstar]
  nstar <- apply(mat[, jstar], 2, sum)
  rstar <- length(nstar)
  idx <- match(y, ystar)
  return(list(
    ystar = ystar, zstar = zstar, nstar = nstar,
    rstar = rstar, idx = idx
  ))
}