Merge pull request #543 from ishaan-arora-1/fix/ppc-accept-draws-objects-542

Accept posterior::draws objects in PPC/PPD functions

Author: jgabry

R/helpers-ppc.R

@@ -58,15 +58,20 @@ validate_y <- function(y) {
 #' Validate predictions (`yrep` or `ypred`)
 #'
 #' Checks that `predictions` is a numeric matrix, doesn't have any NAs, and has
-#' the correct number of columns.
+#' the correct number of columns. If `predictions` is a `posterior::draws`
+#' object it is first coerced to a matrix.
 #'
-#' @param predictions The user's `yrep` or `ypred` object (SxN matrix).
+#' @param predictions The user's `yrep` or `ypred` object (SxN matrix or a
+#'   `posterior::draws` object).
 #' @param `n_obs` The number of observations (columns) that `predictions` should
 #'   have, if applicable.
 #' @return Either throws an error or returns a numeric matrix.
 #' @noRd
 validate_predictions <- function(predictions, n_obs = NULL) {
-  # sanity checks
+  if (posterior::is_draws(predictions)) {
+    predictions <- posterior::as_draws_matrix(predictions)
+    predictions <- unclass(predictions)
+  }
   stopifnot(is.matrix(predictions), is.numeric(predictions))
   if (!is.null(n_obs)) {
     stopifnot(length(n_obs) == 1, n_obs == as.integer(n_obs))

man-roxygen/args-y-yrep.R

@@ -1,8 +1,9 @@
 #' @param y A vector of observations. See **Details**.
 #' @param yrep An `S` by `N` matrix of draws from the posterior (or prior)
-#'   predictive distribution. The number of rows, `S`, is the size of the
-#'   posterior (or prior) sample used to generate `yrep`. The number of columns,
-#'   `N` is the number of predicted observations (`length(y)`). The columns of
-#'   `yrep` should be in the same order as the data points in `y` for the plots
-#'   to make sense. See the **Details** and **Plot Descriptions** sections for
-#'   additional advice specific to particular plots.
+#'   predictive distribution, or a [`posterior::draws`] object. The number of
+#'   rows, `S`, is the size of the posterior (or prior) sample used to generate
+#'   `yrep`. The number of columns, `N` is the number of predicted observations
+#'   (`length(y)`). The columns of `yrep` should be in the same order as the
+#'   data points in `y` for the plots to make sense. See the **Details** and
+#'   **Plot Descriptions** sections for additional advice specific to particular
+#'   plots.

man-roxygen/args-ypred.R

@@ -1,4 +1,5 @@
 #' @param ypred An `S` by `N` matrix of draws from the posterior (or prior)
-#'   predictive distribution. The number of rows, `S`, is the size of the
-#'   posterior (or prior) sample used to generate `ypred`. The number of
-#'   columns, `N`, is the number of predicted observations.
+#'   predictive distribution, or a [`posterior::draws`] object. The number of
+#'   rows, `S`, is the size of the posterior (or prior) sample used to generate
+#'   `ypred`. The number of columns, `N`, is the number of predicted
+#'   observations.