R/calc_correlation.r

In vbfelix/relper: Miscellaneous Functions for Data Preparation, Cleaning, and Visualization

#' Correlation coefficents computation
#'
#' @description Computation of correlation coefficients.
#'
#' @eval arg_vector("x","numeric")
#' @eval arg_vector("y","numeric")
#' @eval arg_value("type","character",action = "is the type of the correlation to be computed")
#'
#' @details Currently, it is possible to compute the following metrics:
#'
#' \cr - Kendall's Tau correlation coefficient
#' \cr - Pearson linear correlation coefficient
#' \cr - Spearmann correlation coefficient
#'
#' @return A numeric single value with the computed value.
#' @export
#'
#' @examples
#'
#' x <- rnorm(100,1)
#'
#' calc_correlation(x,x)
#'

calc_correlation <-
  function(
    x,
    y,
    type = c("pearson","kendall","spearman")
    ){

  stopifnot(is.numeric(x), length(x) > 1)

  stopifnot(is.numeric(y), length(y) > 1)

  stopifnot(length(x) == length(y))

  stopifnot(is.character(type))

  type <- match.arg(type)

  y_values <- unique(y)

  x_values <- unique(x)

  n <- length(x)

  # kendall -----------------------------------------------------------------

  if(type == "kendall"){

    output <- stats::cor(x = x,y = y,use = "na.or.complete",method = "kendall")

  }

  # pearson -----------------------------------------------------------------

  if(type == "pearson"){

    output <- stats::cor(x = x,y = y,use = "na.or.complete",method = "pearson")

  }

  # spearman -----------------------------------------------------------------

  if(type == "spearman"){

    output <- stats::cor(x = x,y = y,use = "na.or.complete",method = "spearman")

  }

  return(unname(output))

}