Merge branch 'master' into release-1.0

Author: OlivierHnt

Project.toml

@@ -29,7 +29,7 @@ IntervalArithmeticSparseArraysExt = "SparseArrays"
 [compat]
 CRlibm = "1.0.2"
 DiffRules = "1"
-ForwardDiff = "0.10"
+ForwardDiff = "0.10, 1"
 IntervalSets = "0.7"
 LinearAlgebra = "1.10"
 MacroTools = "0.5"

ext/IntervalArithmeticDiffRulesExt.jl

@@ -3,8 +3,8 @@ module IntervalArithmeticDiffRulesExt
 using IntervalArithmetic
 import DiffRules
 
-function DiffRules._abs_deriv(x::Interval)
-    r = sign(bareinterval(x))
+function DiffRules._abs_deriv(x::Interval{T}) where {T<:IntervalArithmetic.NumTypes}
+    r = ifelse(isthinzero(x), bareinterval(-one(T), one(T)), sign(bareinterval(x)))
     d = decoration(x)
     d = min(d, ifelse(in_interval(0, x), trv, d)) # if `x` contains 0, then `trv` decoration
     return IntervalArithmetic._unsafe_interval(r, d, isguaranteed(x))

test/interval_tests/forwarddiff.jl

@@ -10,7 +10,7 @@ end
     @testset "abs" begin
         @test ForwardDiff.derivative(abs, interval(-2, -1)) === interval(-1, -1, com)
         @test ForwardDiff.derivative(abs, interval( 1,  2)) === interval( 1,  1, com)
-        @test ForwardDiff.derivative(abs, interval(   0  )) === interval(   0  , trv)
+        @test ForwardDiff.derivative(abs, interval(   0  )) === interval(-1,  1, trv)
         @test ForwardDiff.derivative(abs, interval(-1,  0)) === interval(-1,  0, trv)
         @test ForwardDiff.derivative(abs, interval( 0,  1)) === interval( 0,  1, trv)
         @test ForwardDiff.derivative(abs, interval(-2,  2)) === interval(-1,  1, trv)
@@ -21,8 +21,10 @@ end
         g(x) = abs(x)^2
         @test     ForwardDiff.derivative(g,             interval(-1, 1))   ===  interval(convert(Interval{Float64}, -2), convert(Interval{Float64}, 2), trv)
         @test all(ForwardDiff.gradient(  v -> g(v[1]), [interval(-1, 1)]) .=== [interval(convert(Interval{Float64}, -2), convert(Interval{Float64}, 2), trv)])
-        @test all(ForwardDiff.hessian(   v -> g(v[1]), [interval(  0  )]) .=== [interval(convert(Interval{Float64}, 0.0), trv)])
+        @test all(ForwardDiff.hessian(   v -> g(v[1]), [interval(  1  )]) .=== [interval(convert(Interval{Float64},  2), trv)])
+        @test all(ForwardDiff.hessian(   v -> g(v[1]), [interval( -1  )]) .=== [interval(convert(Interval{Float64},  2), trv)])
         @test all(ForwardDiff.hessian(   v -> g(v[1]), [interval(-1, 1)]) .=== [interval(convert(Interval{Float64}, -2), convert(Interval{Float64}, 2), trv)])
+        @test all(ForwardDiff.hessian(   v -> g(v[1]), [interval(  0  )]) .=== [interval(convert(Interval{Float64}, -2), convert(Interval{Float64}, 2), trv)])
     end
 
     @testset "sin" begin