added function to pull knot distribution -- closes #130

R/getKnotDist.R

@@ -0,0 +1,34 @@
+#' Pull the set of knots for dynamic genes across each lineage.
+#'
+#' @name getKnotDist
+#' @author Jack Leary
+#' @import magrittr
+#' @importFrom purrr imap reduce
+#' @description Pulls knot locations for dynamic genes across each lineage, allowing comparisons of where transcriptional switches occur between lineages.
+#' @param test.dyn.res The output from \code{\link{testDynamic}}. Defaults to NULL.
+#' @param dyn.genes The set of genes to pull knots for. If unspecified, pulls knots for all modeled genes. Defaults to NULL.
+#' @return A data.frame containing gene name, lineage ID, and knot location in pseudotime.
+#' @export
+#' @examples
+#' \dontrun{
+#' getKnotDist(gene_stats)
+#' }
+
+getKnotDist <- function(test.dyn.res = NULL, dyn.genes = NULL) {
+  # check inputs
+  if (is.null(test.dyn.res)) { stop("You forgot one of the arguments to getKnotDist().") }
+  if (is.null(dyn.genes)) {
+    dyn.genes <- names(test.dyn.res)
+  }
+  # pull knots per-lineage
+  knot_df <- purrr::imap(test.dyn.res[dyn.genes], \(x, y) {
+    purrr::imap(x, \(z, w) {
+      data.frame(gene = y,
+                 lineage = w,
+                 knot = z$MARGE_Slope_Data$Breakpoint)
+    }) %>%
+      purrr::reduce(rbind)
+  }) %>%
+    purrr::reduce(rbind)
+  return(knot_df)
+}