sinpi, cospi

src/primitive.jl

@@ -1,6 +1,6 @@
 import Base: abs, abs2
 import Base: exp, exp2, exp10, expm1, log, log2, log10, log1p, inv, sqrt, cbrt
-import Base: sin, cos, tan, cot, sec, csc, sinh, cosh, tanh, coth, sech, csch
+import Base: sin, cos, tan, cot, sec, csc, sinh, cosh, tanh, coth, sech, csch, sinpi, cospi
 import Base: asin, acos, atan, acot, asec, acsc, asinh, acosh, atanh, acoth, asech, acsch
 import Base: sinc, cosc
 import Base: +, -, *, /, \, ^, >, <, >=, <=, ==
@@ -69,6 +69,9 @@ for func in (:sin, :cos)
     end
 end
 
+@inline sinpi(t::TaylorScalar) = sin(π * t)
+@inline cospi(t::TaylorScalar) = cos(π * t)
+
 # Binary
 
 for op in [:>, :<, :(==), :(>=), :(<=)]

test/primitive.jl

@@ -14,7 +14,8 @@ end
 
 @testset "Unary functions" begin
     some_number = 3.7
-    for f in (x -> exp(x^2), expm1, exp2, exp10, x -> sin(x^2), x -> cos(x^2), sqrt, cbrt,
+    for f in (x -> exp(x^2), expm1, exp2, exp10, x -> sin(x^2), x -> cos(x^2), sinpi, cospi,
+            sqrt, cbrt,
             inv), order in (1, 4)
         fdm = central_fdm(12, order)
         @test derivative(f, some_number, order)≈fdm(f, some_number) rtol=1e-6