Merge pull request #423 from theabhirath/broadcast-act

Define activation functions taking arrays as input

Author: darsnack

src/activations.jl

@@ -731,10 +731,9 @@ function softshrink(x, λ = 0.5)
     ifelse(hi > 0, ifelse(lo < 0, zero(hi), lo), hi)
 end
 
-# Provide an informative error message if activation functions are called with an array
+# Define broadcasts for activation functions on arrays
 for f in ACTIVATIONS
-    @eval $(f)(x::AbstractArray, args...) =
-      error("Use broadcasting (`", $(string(f)), ".(x)`) to apply activation functions to arrays.")
+  @eval $(f)(x::AbstractArray, args...) = $(f).(x, args...)
 end
 
 ## Faster, less accurate, versions of some.

test/activations.jl

@@ -93,10 +93,14 @@ end
 @testset "Array input -> error" begin
     x = rand(5)
     for a in ACTIVATION_FUNCTIONS
-        @test_throws ErrorException a(x)
+        @test size(a(x)) == size(x)
+        grad = Zygote.gradient(p -> sum(a(p)), x)
+        @test size(grad[1]) == size(x)
     end
     for a in BINARY_ACTIVATIONS
-        @test_throws ErrorException a(x, 0.1)
+        @test size(a(x, 0.1)) == size(x)
+        grad = Zygote.gradient(p -> sum(a(p, 0.1)), x)
+        @test size(grad[1]) == size(x)
     end
 end