Add an extension for SparseArrays

Author: OlivierHnt

Project.toml

@@ -16,13 +16,15 @@ DiffRules = "b552c78f-8df3-52c6-915a-8e097449b14b"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
 IntervalSets = "8197267c-284f-5f27-9208-e0e47529a953"
 RecipesBase = "3cdcf5f2-1ef4-517c-9805-6587b60abb01"
+SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 
 [extensions]
 IntervalArithmeticDiffRulesExt = "DiffRules"
 IntervalArithmeticForwardDiffExt = "ForwardDiff"
 IntervalArithmeticIntervalSetsExt = "IntervalSets"
 IntervalArithmeticLinearAlgebraExt = "LinearAlgebra"
 IntervalArithmeticRecipesBaseExt = "RecipesBase"
+IntervalArithmeticSparseArraysExt = "SparseArrays"
 
 [compat]
 CRlibm = "1.0.2"
@@ -35,4 +37,5 @@ OpenBLASConsistentFPCSR_jll = "0.3.29"
 Printf = "1.10"
 RecipesBase = "1"
 RoundingEmulator = "0.2"
+SparseArrays = "1.10.0"
 julia = "1.10"

ext/IntervalArithmeticForwardDiffExt.jl

@@ -98,7 +98,7 @@ function (constant::Constant)(::Dual{T, Interval{S}}) where {T, S}
     return Dual{T}(interval(S, constant.value), interval(S, 0.0))
 end
 
-function (piecewise::Piecewise)(dual::Dual{T, <:Interval}) where {T}
+function (piecewise::Piecewise)(dual::Dual{T,<:Interval}) where {T}
     X = value(dual)
     input_domain = Domain(X)
     if !overlap_domain(input_domain, piecewise)
@@ -135,5 +135,4 @@ function (piecewise::Piecewise)(dual::Dual{T, <:Interval}) where {T}
     return Dual{T}(primal, tuple(partial...))
 end
 
-
 end

ext/IntervalArithmeticSparseArraysExt.jl

@@ -0,0 +1,10 @@
+module IntervalArithmeticSparseArraysExt
+
+using IntervalArithmetic
+import SparseArrays
+
+SparseArrays._iszero(x::Interval) = isthinzero(x)
+
+SparseArrays._isnotzero(x::Interval) = !isthinzero(x)
+
+end

test/interval_tests/forwarddiff.jl

@@ -19,9 +19,9 @@ end
         @test ForwardDiff.derivative(f, interval(-1, 1)) === interval(-2,  2, trv)
 
         g(x) = abs(x)^2
-        @test     ForwardDiff.derivative(g,             interval(-1, 1) )  ===  interval(convert(Interval{Float64}, -2), convert(Interval{Float64}, 2), trv)
+        @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_broken all(ForwardDiff.hessian(   v -> g(v[1]), [interval(  0  )]) .=== [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