Add panel_data coercion methods

R/panel_methods.R

@@ -0,0 +1,46 @@
+#' @export
+
+as_pdata.frame <- function(x) {
+
+  if (!requireNamespace("plm")) {
+    stop_wrap("You must have the plm package to convert to pdata.frame.")
+  }
+
+  pdata.frame(unpanel(x), index = c(get_id(x), get_wave(x)))
+
+}
+
+#' @rdname panel_data
+#' @export
+as_panel_data <- function(x, ...) {
+  UseMethod("as_panel_data")
+}
+
+#' @rdname panel_data
+#' @export
+as_panel_data.default <- function(x, id = id, wave = wave, ...) {
+  panel_data(x, id = !! id, wave = !! wave, ...)
+}
+
+#' @rdname panel_data
+#' @export
+as_panel_data.pdata.frame <- function(x, ...) {
+  indices <- plm::index(x)
+  id <- names(indices)[1]
+  wave <- names(indices)[2]
+  if (id %nin% names(x)) {
+    x[id] <- indices[id]
+  }
+  if (wave %nin% names(x)) {
+    x[wave] <- indices[wave]
+  }
+  panel_data(x, id = !! id, wave = !! wave, ...)
+}
+
+#' @rdname panel_data
+#' @export
+as_panel <- as_panel_data
+
+#' as_panel_data.tsibble <- function(x, ...) {
+#'   
+#' }