Add registration for Base.clamp

src/extra_functions.jl

@@ -68,6 +68,16 @@ end
 @register_symbolic Base.rand(x)
 @register_symbolic Base.randn(x)
 
+@register_symbolic Base.clamp(x, y, z)
+
+function derivative(::typeof(Base.clamp), args::NTuple{3, Any}, ::Val{1})
+    x, l, h = args
+    T = promote_type(symtype(x), symtype(l), symtype(h))
+    z = zero(T)
+    o = one(T)
+    ifelse(x<l, z, ifelse(x>h, z, o))
+end
+
 @register_symbolic Distributions.pdf(dist,x)
 @register_symbolic Distributions.logpdf(dist,x)
 @register_symbolic Distributions.cdf(dist,x)

test/overloads.jl

@@ -186,6 +186,9 @@ x = Num.(randn(10))
 @test norm(x, 1) == norm(Symbolics.value.(x), 1)
 @test norm(x, 1.2) == norm(Symbolics.value.(x), 1.2)
 
+@test clamp.(x, 0, 1) == clamp.(Symbolics.value.(x), 0, 1)
+@test isequal(Symbolics.derivative(clamp(a, 0, 1), a), ifelse(a < 0, 0, ifelse(a>1, 0, 1)))
+
 @variables x[1:2]
 @test isequal(scalarize(norm(x)), sqrt(abs2(x[1]) + abs2(x[2])))
 @test isequal(scalarize(norm(x, Inf)), max(abs(x[1]), abs(x[2])))