Error for glmnet models is there is not exactly one value for penalty

Author: juliasilge

R/linear_reg.R

@@ -112,6 +112,13 @@ translate.linear_reg <- function(x, engine = x$engine, ...) {
     # Since the `fit` information is gone for the penalty, we need to have an
     # evaluated value for the parameter.
     x$args$penalty <- rlang::eval_tidy(x$args$penalty)
+    if (length(x$args$penalty) != 1) {
+      rlang::abort(c(
+        "For the glmnet engine, `penalty` must be a single number.",
+        glue::glue("There are {length(x$args$penalty)} values for `penalty`."),
+        "To try multiple values for total regularization, use the tune package."
+      ))
+    }
   }
 
   x

R/logistic_reg.R

@@ -115,6 +115,13 @@ translate.logistic_reg <- function(x, engine = x$engine, ...) {
     # Since the `fit` information is gone for the penalty, we need to have an
     # evaluated value for the parameter.
     x$args$penalty <- rlang::eval_tidy(x$args$penalty)
+    if (length(x$args$penalty) != 1) {
+      rlang::abort(c(
+        "For the glmnet engine, `penalty` must be a single number.",
+        glue::glue("There are {length(x$args$penalty)} values for `penalty`."),
+        "To try multiple values for total regularization, use the tune package."
+      ))
+    }
   }
 
   if (engine == "LiblineaR") {