add helper function for percentile normalization

analyses/functions/helper-functions.R

@@ -0,0 +1,35 @@
+
+
+require(dplyr)
+require(tibble)
+
+#' Percentile Normalization of a Column in a Tibble
+#'
+#' This function normalizes a specified column in a tibble by transforming each value
+#' to the percentile in which it falls relative to the entire column. 
+#'
+#' @param data A tibble containing the data.
+#' @param colname A string representing the name of the column to be normalized.
+#'
+#' @return A tibble with an additional column named "<colname>_percentile" where each
+#'         entry represents the percentile of the corresponding value in the original
+#'         column. Percentile values range from 0 to 1.
+#'
+#' @examples
+#' library(tibble)
+#' library(dplyr)
+#'
+#' # Example tibble
+#' df <- tibble::tibble(
+#'   approved_symbol = c("ABCG2", "ACE", "ACTA2"),
+#'   source_count = c(3, 10, 6)
+#' )
+#'
+#' # Applying normalization
+#' df_normalized <- normalize_percentile(df, "source_count")
+#'
+#' @export
+normalize_percentile <- function(data, colname) {
+  data %>%
+    mutate("{colname}_percentile" := rank(!!sym(colname), ties.method = "average") / n()) 
+}