Added round method for RoundFromZero

JuliaLang · Sep 12, 2021 · 914c4c3 · 914c4c3
1 parent 211ed19
commit 914c4c3
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Showing 3 changed files with 20 additions and 2 deletions.
diff --git a/base/floatfuncs.jl b/base/floatfuncs.jl
@@ -236,6 +236,10 @@ function round(x::T, ::RoundingMode{:NearestTiesUp}) where {T <: AbstractFloat}
     copysign(floor((x + (T(0.25) - eps(T(0.5)))) + (T(0.25) + eps(T(0.5)))), x)
 end
 
+function Base.round(x::AbstractFloat, ::typeof(RoundFromZero))
+    signbit(x) ? round(x, RoundDown) : round(x, RoundUp)
+end
+
 # isapprox: approximate equality of numbers
 """
     isapprox(x, y; atol::Real=0, rtol::Real=atol>0 ? 0 : √eps, nans::Bool=false[, norm::Function])

diff --git a/base/rounding.jl b/base/rounding.jl
@@ -37,7 +37,7 @@ Currently supported rounding modes are:
 - [`RoundNearestTiesAway`](@ref)
 - [`RoundNearestTiesUp`](@ref)
 - [`RoundToZero`](@ref)
-- [`RoundFromZero`](@ref) ([`BigFloat`](@ref) only)
+- [`RoundFromZero`](@ref)
 - [`RoundUp`](@ref)
 - [`RoundDown`](@ref)
 """
@@ -76,7 +76,6 @@ const RoundDown = RoundingMode{:Down}()
     RoundFromZero
 
 Rounds away from zero.
-This rounding mode may only be used with `T == BigFloat` inputs to [`round`](@ref).
 
 # Examples
 ```jldoctest

diff --git a/test/rounding.jl b/test/rounding.jl
@@ -128,6 +128,16 @@ end
             else
                 @test u === r
             end
+
+            r = round(u, RoundFromZero)
+            if isfinite(u)
+                @test isfinite(r)
+                @test isinteger(r)
+                @test signbit(u) ? (r == floor(u)) : (r == ceil(u))
+                @test signbit(u) == signbit(r)
+            else
+                @test u === r
+            end
         end
     end
 end
@@ -171,6 +181,7 @@ end
                 @test round.(y) ≈ t[(i+1+isodd(i>>2))>>2 for i in r]
                 @test broadcast(x -> round(x, RoundNearestTiesAway), y) ≈ t[(i+1+(i>=0))>>2 for i in r]
                 @test broadcast(x -> round(x, RoundNearestTiesUp), y) ≈ t[(i+2)>>2 for i in r]
+                @test broadcast(x -> round(x, RoundFromZero), y) ≈ t[(i+3*(i>=0))>>2 for i in r]
             end
         end
     end
@@ -190,6 +201,10 @@ end
     @test round(Int,-2.5,RoundNearestTiesUp) == -2
     @test round(Int,-1.5,RoundNearestTiesUp) == -1
     @test round(Int,-1.9) == -2
+    @test round(Int,nextfloat(1.0),RoundFromZero) == 2
+    @test round(Int,-nextfloat(1.0),RoundFromZero) == -2
+    @test round(Int,prevfloat(1.0),RoundFromZero) == 1
+    @test round(Int,-prevfloat(1.0),RoundFromZero) == -1
     @test_throws InexactError round(Int64, 9.223372036854776e18)
     @test       round(Int64, 9.223372036854775e18) == 9223372036854774784
     @test_throws InexactError round(Int64, -9.223372036854778e18)