R/SimNormalMix.R

In feji3769/simplesim: Simulate Data for Model Building

#' @title Simulate Normal Mixture in 1d
#' @description Simulate data from m normal distributions
#' centered at different locations with different
#' variances.
#' @param N number of data points to simulate.
#' @param mu vector of means.
#' @param sigma vector of standard deviations.
#' @param p vector of weights for each distribution.
#' @param seed seed for RNG (default = NULL).
#' @return list(x = x, label = label)
#' @export
#' @examples
#' N = 100
#' mu = c(1,2,3)
#' sigma = c(0.1, 0.1, 0.1)
#' p = c(1/4, 1/4, 1/2)
#' SimNormalMix(N, mu, sigma, p)
SimNormalMix = function(N, mu, sigma, p, seed = NULL){
  if(!is.null(seed)){
    .checkSeed(seed)
    set.seed(seed)
  }
  .checkPositive(N)
  .requireConstant(N)
  .checkPositive(sigma)
  .checkPositive(p)
  
  
  if(sum(p) != 1){
    stop("p must sum to one.")
  }
  
  if(length(mu) != length(sigma)){
    stop("sigma and mu must be the same length.")
  }
  if(N < length(mu)){
   stop("N must be greater than or equal to length of mu.") 
  }
  
  result = SimMixC(N, mu, sigma, p)
  return(list(x = result[ , 2], y = result[ , 1]))
}