avoid defining ± for Intervals

src/IntervalMatrices.jl

@@ -33,14 +33,9 @@ if vIA >= v"0.22"
     import Base: intersect
     export ±, midpoint_radius
 
-    function ±(x::Number, y::Number)
-        return x + interval(-y, y)
-    end
-
     function Base.:(==)(A::AbstractMatrix{<:Interval}, B::AbstractMatrix{<:Interval})
         return size(A) == size(B) && all(map((a, b) -> isequal_interval(a, b), A, B))
     end
-
 else
     import IntervalArithmetic: ±, midpoint_radius
 

src/exponential.jl

@@ -96,7 +96,7 @@ function _exp_remainder(A::IntervalMatrix{T}, t, p; n=checksquare(A)) where {T}
     end
     M = exp(C * t)
     Y = M - Q
-    Γ = IntervalMatrix(fill(zero(T) ± one(T), (n, n)))
+    Γ = IntervalMatrix(fill(interval(-one(T), one(T)), (n, n)))
     E = Γ * Y
     return E
 end
@@ -111,7 +111,7 @@ function _exp_remainder_series(A::IntervalMatrix{T}, t, p; n=checksquare(A)) whe
     @assert c < 1 "the remainder of the matrix exponential could not be " *
                   "computed because a convergence condition is not satisfied: $c ≥ 1 " *
                   "but it should be smaller than 1; try choosing a larger order"
-    Γ = IntervalMatrix(fill(zero(T) ± one(T), (n, n)))
+    Γ = IntervalMatrix(fill(interval(-one(T), one(T)), (n, n)))
     return Γ * ((nA * t)^(p + 1) * (1 / factorial(p + 1) * 1 / (1 - c)))
 end
 

src/matrix.jl

@@ -22,10 +22,10 @@ parametrized in the number field, the interval type, and the matrix type.
 ### Examples
 
 ```jldoctest
-julia> A = IntervalMatrix([-0.9±0.1 0±0; 0±0 -0.9±0.1])
+julia> A = IntervalMatrix([-1 .. -0.8 0 .. 0; 0 .. 0 -1 .. -0.8])
 2×2 IntervalMatrix{Float64, Interval{Float64}, Matrix{Interval{Float64}}}:
- [-1.00001, -0.7999999]   [0.0, 0.0]
-  [0.0, 0.0]             [-1.00001, -0.7999999]
+ [-1.0, -0.7999999]   [0.0, 0.0]
+  [0.0, 0.0]         [-1.0, -0.7999999]
 ```
 
 An interval matrix proportional to the identity matrix can be built using the
@@ -182,7 +182,7 @@ function ±(C::MT, S::MT) where {T,MT<:AbstractMatrix{T}}
                                               "radii matrix should match, but they are $(size(C)) " *
                                               "and $(size(S)) respectively"))
 
-    return IntervalMatrix(map((x, y) -> x ± y, C, S))
+    return IntervalMatrix(map((x, y) -> interval(x - y, x + y), C, S))
 end
 
 for op in (:Adjoint, :Bidiagonal, :Diagonal, :Hermitian,