R/calc_vi.R

In MetaVolcanoR: Gene Expression Meta-analysis Visualization Tool

#' A function to calculate variance from confidence interval limits
#'
#' This function takes the limits of a confidence interval (95%) 
#' a calculate a variance
#' @param diffexp data.frame/data.table containing differential expression
#'        results
#' @param llcol column name of the fold change coinfidence interval left limit
#'        name <string>
#' @param rlcol column name of the fold change coinfidence interval left limit
#'        name <string>
#' @keywords variance from confidence interval
#' @return \code{data.table/data.frame} with a new \code{vi} variable
#' @export
#' @examples
#' data(diffexplist)
#' diffexp <- calc_vi(diffexplist[[1]], "CI.L", "CI.R")
#' head(diffexp, 3)
calc_vi <- function(diffexp, llcol, rlcol) {
    diffexp[['vi']] <- 
        ((as.numeric(diffexp[[rlcol]]) - as.numeric(diffexp[[llcol]]))/3.92)^2
    diffexp
}