Add method for rem2pi

Fix #27.

NEWS.md

@@ -1,6 +1,14 @@
 History of Measurements.jl
 ==========================
 
+v1.1.0 (2018-1?-??)
+-------------------
+
+### New Features
+
+* New method for `rem2pi`
+  ([#29](https://github.com/JuliaPhysics/Measurements.jl/issues/29)).
+
 v1.0.2 (2018-09-26)
 -------------------
 

src/math.jl

@@ -902,13 +902,18 @@ Base.mod(a::Measurement, b::Measurement) = a - fld(a, b)*b
 Base.mod(a::Measurement, b::Real) = result(mod(a.val, b), 1, a)
 Base.mod(a::Real, b::Measurement) = result(mod(a, b.val), -fld(a, b.val), b)
 
-Base.# Use definition of "rem" function:
-Base.# http://docs.julialang.org/en/stable/manual/mathematical-operations/#division-functions
+# Use definition of "rem" function:
+# https://docs.julialang.org/en/latest/manual/mathematical-operations/#Division-functions-1
 Base.rem(a::Measurement, b::Measurement) = a - div(a, b)*b
 Base.rem(a::Measurement, b::Real) = result(rem(a.val, b), 1, a)
 Base.rem(a::Real, b::Measurement) = result(rem(a, b.val), -div(a, b.val), b)
+Base.rem(a::Measurement, b::Union{Measurement,Float64}, ::RoundingMode{:Nearest}) =
+    a - b * round(a / b, RoundNearest)
+Base.rem(a::Float64, b::Measurement, ::RoundingMode{:Nearest}) =
+    a - b * round(a / b, RoundNearest)
 
 Base.mod2pi(a::Measurement) = result(mod2pi(a.val), 1, a)
+Base.rem2pi(a::Measurement, r::RoundingMode) = result(rem2pi(a.val, r), 1, a)
 
 ### Machine precision
 
@@ -924,9 +929,10 @@ Base.typemax(::Type{Measurement{T}}) where {T<:AbstractFloat} = typemax(T)
 
 ### Rounding
 
-Base.round(a::Measurement; kwargs...) =
-    measurement(round(value(a); kwargs...), round(uncertainty(a); kwargs...))
-Base.round(::Type{T}, a::Measurement) where {T<:Integer} = round(T, a.val)
+Base.round(a::Measurement, r::RoundingMode=RoundNearest; kwargs...) =
+    measurement(round(value(a), r; kwargs...), round(uncertainty(a); kwargs...))
+Base.round(::Type{T}, a::Measurement, r::RoundingMode=RoundNearest) where {T<:Integer} =
+    round(T, a.val, r)
 Base.floor(a::Measurement) = measurement(floor(a.val))
 Base.floor(::Type{T}, a::Measurement) where {T<:Integer} = floor(T, a.val)
 Base.ceil(a::Measurement) = measurement(ceil(a.val))

test/runtests.jl

@@ -495,12 +495,27 @@ end
         @test @inferred(mod(-5.8, a)) ≈ @inferred(-5.8 - fld(-5.8, a) * a)
         @test @inferred(rem(a, -3.7)) ≈ @inferred(a + div(a, -3.7) * 3.7)
         @test @inferred(rem(-4.9, a)) ≈ @inferred(-4.9 - div(-4.9, a) * a)
+        @test @inferred(rem(a, 4.27, RoundNearest)) ≈
+            a - 4.27 * round(a / 4.27, RoundNearest)
+        @test @inferred(rem(-5.1, a, RoundNearest)) ≈
+            -5.1 - a * round(-5.1 / a, RoundNearest)
+        @test @inferred(rem(a, -1.2, RoundToZero)) ≈ rem(a, -1.2)
+        @test @inferred(rem(3.45, a, RoundToZero)) ≈ rem(3.45, a)
+        @test @inferred(rem(a, 6.7, RoundDown)) ≈ mod(a, 6.7)
+        @test @inferred(rem(-8.9, a, RoundDown)) ≈ mod(-8.9, a)
+        @test @inferred(rem(a, -3.14, RoundUp)) ≈ mod(a, 3.14)
+        @test @inferred(rem(2.718, a, RoundUp)) ≈ mod(2.718, -a)
         for b in (10w, x, y)
             @test @inferred(mod(a, b)) ≈ a - fld(a, b)*b
             @test @inferred(rem(a, b)) ≈ a - div(a, b)*b
+            @test @inferred(rem(a, b, RoundNearest)) ≈ a - b * round(a / b, RoundNearest)
         end
     end
     @test @inferred(mod2pi(pi*x)) ≈ measurement(pi, 0.1*pi)
+    for r in (RoundNearest, RoundToZero, RoundUp, RoundDown), a in (3x, 5y, 10w)
+        @test @inferred(rem2pi(a, r)) ≈ rem(a, 2pi, r)
+        @test rem2pi(a, r) ≈ a - 2pi * round(a / (2pi), r)
+    end
 end
 
 @testset "Machine precisionx" begin