R/utils_get_combinations.R

In correlation: Methods for Correlation Analysis

#' @keywords internal
.get_combinations <- function(data,
                              data2 = NULL,
                              redundant = TRUE,
                              include_factors = TRUE,
                              multilevel = FALSE,
                              method = "pearson") {
  data <- .clean_data(data, include_factors = include_factors, multilevel = multilevel)

  if (method == "polychoric") {
    vars <- names(data)
  } else if (multilevel) {
    vars <- names(data[sapply(data, is.numeric)])
  } else {
    vars <- names(data)
  }



  # Find pairs
  if (is.null(data2)) {
    vars2 <- vars
  } else {
    data2 <- .clean_data(data2, include_factors = include_factors, multilevel = multilevel)
    data2_nums <- data2[sapply(data2, is.numeric)]
    vars2 <- names(data2_nums)
  }

  combinations <- expand.grid(vars, vars2, stringsAsFactors = FALSE)
  combinations <- combinations[order(match(combinations$Var1, vars), match(combinations$Var2, vars2)), ]

  row.names(combinations) <- NULL
  names(combinations) <- c("Parameter1", "Parameter2")

  if (!redundant) {
    combinations <- .remove_redundant(combinations)
  }

  combinations
}