fix issue with degree variants; close issue #304 (#305)

Author: jverzani

src/mathfuns.jl

@@ -28,7 +28,7 @@ degree_variants = (:sind, :cosd, :tand, :cotd, :secd, :cscd,
 for  methvar in degree_variants
     meth = Symbol(String(methvar)[1:end-1])
     @eval begin
-        (Base.$methvar)(ex::SymbolicObject) = ($meth)(PI*ex)
+        (Base.$methvar)(ex::SymbolicObject) = ($meth)((PI/180)*ex)
     end
 end
 

test/tests.jl

@@ -565,6 +565,10 @@ end
     res = dsolve(diffeq, F(t), ics=(F, 0, 2))  # 2exp(3t)
     @test lambdify(res)(1) ≈ 2*exp(3*1)
 
+    # issue 304 wrong values for sind, ...
+    a = Sym(45)
+    @test sind(a) == sin(PI/4)
+
 end
 
 @testset "generic programming, issue 223" begin