R/hadamard.R

In fastmatrix: Fast Computation of some Matrices Useful in Statistics

## ID: hadamard.R, last updated 2021-02-14, F.Osorio

hadamard <- function(x, y = x)
{ ## returns the element-wise product of two matrices x and y
  if (is.data.frame(x))
    x <- as.matrix(x)
  if (is.vector(x))
    x <- as.matrix(x)
  if (!is.matrix(x))
    stop("supply a matrix-like 'x'")
  if (!is.numeric(x))
    stop("argument x is not a numeric matrix" )

  if (is.data.frame(y))
    y <- as.matrix(y)
  if (is.vector(y))
    y <- as.matrix(y)
  if (!is.matrix(y))
    stop("supply a matrix-like 'y'")
  if (!is.numeric(y))
    stop("argument y is not a numeric matrix" )

  dx <- dim(x)
  dy <- dim(y)
  if (!all(dx == dy))
    stop( "arguments x and y do not have the same order.")

  n <- prod(dx)
  z <- .C("hadamard_prod",
          x = as.double(x),
          y = as.double(y),
          n = as.integer(n),
          prod = double(n))$prod
  z <- matrix(z, nrow = dx[1], ncol = dx[2])
  z
}