R/energy_global.R

In significantstats/gatingfc: Automated gating of flow cytometry data

#' Global energy of lattice grid
#'
#' \code{energy_global} calculates the complete global energy for the lattice
#' grid. The tendency of the overall grid position is provided through
#' \code{trend}.
#'
#' @param x the lattice grid for which the global energy is required
#' @param trend the global tendancy of the lattice grid
#'
#' @return the value of the global energy function
#'
#' @examples
#'   x <- matrix(sample(c(-1, 1), size = 16, prob = c(0.6, 0.4), replace = TRUE), nrow = 4)
#'   energy_global(x)
#'
#' @author Kevin Brosnan (\email{kevin.c.brosnan@@ul.ie})
#'
#' @export

energy_global <- function(x, trend = -1) {

  if (trend != 1 && trend != -1) {
    stop("'trend' must be either 1 or -1")
  }

  if (class(x) != "matrix" && class(x) != "gatingfc_grid") {
    stop("'x' must be a matrix or of class 'gatingfc_grid'")
  }

  y <- as.matrix(x)

  global <- -sum(y)
  global <- sign(trend) * global
  return(global)
}