R/getfulld.R

In PopED: Population (and Individual) Optimal Experimental Design

#' Create a full D (between subject variability) matrix given a vector of variances and covariances.
#' Note, this does not test matching vector lengths.
#' 
#' @param variance_vector The vector of the variances.
#' @param covariance_vector A vector of the covariances. Written in column major 
#'   order for the lower triangular matrix.
#' @return The full matrix of variances for the between subject variances
#' @example tests/testthat/examples_fcn_doc/examples_getfulld.R
#' @export
#' @keywords internal
## Function translated automatically using 'matlab.to.r()'
## Author: Andrew Hooker

getfulld <- function(variance_vector,covariance_vector=NULL){  
  if (length(variance_vector) == 1) return(as.matrix(variance_vector))
  d = diag_matlab(variance_vector)
  if ((!isempty(covariance_vector) & sum(covariance_vector != 0) > 0)) {
    d[lower.tri(d)] = covariance_vector
    d = t(d) # upper.tri has wrong order, so fill lower, transpose this to upper, then fill lower again
    d[lower.tri(d)] = covariance_vector
  }
  return(d) 
}