diff --git a/test/derivatives.jl b/test/derivatives.jl index 6938412188..515bc6ebb8 100644 --- a/test/derivatives.jl +++ b/test/derivatives.jl @@ -72,3 +72,13 @@ isequal(ModelingToolkit.derivative(Operation(+, [x*y, y, z]), 1), 1) Expression[ModelingToolkit.Constant(1) ModelingToolkit.Constant(0) Differential(t)(x) ModelingToolkit.Constant(1) ModelingToolkit.Constant(0) ModelingToolkit.Constant(0)]) + +# issue 252 +@variables beta, alpha, delta +@variables x1, x2, x3 + +# expression +tmp = beta * (alpha * exp(x1) * x2 ^ (alpha - 1) + 1 - delta) / x3 +# derivative w.r.t. x1 and x2 +t1 = ModelingToolkit.gradient(tmp, [x1, x2]) +@test_nowarn ModelingToolkit.gradient(t1[1], [beta])