R/sim.pheno.qtl.E.R

In agaye/ESPRESSO.E: Power Analysis and Sample Size Calculation for a model with a main effect environmental exposure

#' 
#' @title Generates quantitative outcome data
#' @description The function uses the effects data of the determinants to construct a linear predictor(LP). 
#' The outcome is a normally distributed variable generated with a mean equal to the LP and a standard 
#' deviation of 1.
#' @param num.obs number of subjects to generate.
#' @param pheno.mean mean of the outcome variable in the study population
#' @param pheno.sd standard deviation of the outcome in the study population
#' @param environment environmental exposure data.
#' @param env.efkt effect size of the environmental exposure.
#' @return a numeric vector, the phenotype data
#' @keywords internal
#' @author Gaye A.
#'  
sim.pheno.qtl.E <- function (num.subjects = 10000, pheno.mean = 0, pheno.sd = 1, 
    environment = NULL, env.efkt = 0.25) 
{
    if (is.null(environment)) {
        cat("\n\n ALERT!\n")
        cat(" No environmental exposure data found.\n")
        cat(" Check the argument 'environment'\n")
        stop(" End of process!\n\n", call. = FALSE)
    }
    alpha <- pheno.mean
    beta <- env.efkt
    lp <- alpha + (beta * environment)
    phenotype <- rnorm(num.subjects, lp, pheno.sd)
    return(phenotype)
}