allow all keras activations

Author: EmilHvitfeldt

NAMESPACE

@@ -253,6 +253,7 @@ export(glm_grouped)
 export(has_multi_predict)
 export(importance_weights)
 export(is_varying)
+export(keras_activations)
 export(keras_mlp)
 export(keras_predict_classes)
 export(knit_engine_docs)

R/mlp.R

@@ -192,8 +192,13 @@ keras_mlp <-
            seeds = sample.int(10^5, size = 3),
            ...) {
 
-    act_funs <- c("linear", "softmax", "relu", "elu", "tanh")
-    rlang::arg_match(activation, act_funs)
+    allowed_keras_activation <- keras_activations()
+    good_activation <- activation %in% allowed_keras_activation
+    if (!all(good_activation)) {
+      cli::cli_abort(
+        "{.arg activation} should be one of: {allowed_activation}."
+      )
+    }
 
     if (penalty > 0 & dropout > 0) {
       cli::cli_abort("Please use either dropout or weight decay.", call = NULL)
@@ -344,6 +349,19 @@ mlp_num_weights <- function(p, hidden_units, classes) {
   ((p + 1) * hidden_units) + ((hidden_units+1) * classes)
 }
 
+allowed_keras_activation <-
+ c("elu", "exponential", "gelu", "hard_sigmoid", "linear", "relu", "selu", 
+   "sigmoid", "softmax", "softplus", "softsign", "swish", "tanh")
+
+#' Activation functions for neural networks in keras
+#'
+#' @keywords internal
+#' @return A character vector of values.
+#' @export
+keras_activations <- function() {
+  allowed_keras_activation
+}
+
 ## -----------------------------------------------------------------------------
 
 #' @importFrom purrr map