numbers as a map

Author: daanhb

docs/make.jl

@@ -22,5 +22,5 @@ makedocs(;
 )
 
 deploydocs(;
-    repo="github.com/JuliaApproximation/FunctionMaps.jl.git", devbranch="master",
+    repo="github.com/JuliaApproximation/FunctionMaps.jl.git", devbranch="main",
 )

src/generic/interface.jl

@@ -31,6 +31,8 @@ MapStyle(::Type{<:Map}) = IsMap()
     functionmap(m)
 
 Return a map associated with the object `m`.
+
+The result need not have type `Map`, but its `MapStyle` is `IsMap`.
 """
 functionmap(m::Map) = m
 

src/types/affine.jl

@@ -292,32 +292,6 @@ StaticLinearMap{T,N,M}(A::AbstractMatrix) where {T,N,M} =
 convert(::Type{Map{SVector{N,T}}}, m::VectorLinearMap) where {N,T} = StaticLinearMap{T,N,N}(m.A)
 
 
-# Implement the interface for abstract arrays,
-# representing the linear map x->A*x
-MapStyle(A::AbstractArray) = IsMap()
-
-Map(A::AbstractArray) = LinearMap(A)
-Map{T}(A::AbstractArray) where T = LinearMap{T}(A)
-
-domaintype(A::AbstractArray) = domaintype(Map(A))
-
-applymap(A::AbstractArray, x) = A*x
-mapsize(A::AbstractArray) = size(A)
-
-islinearmap(A::AbstractArray) = true
-isaffinemap(A::AbstractArray) = true
-affinematrix(A::AbstractArray) = A
-affinevector(A::AbstractArray) = zerovector(A)
-
-inverse(A::AbstractMatrix) = inv(A)
-inverse(A::AbstractMatrix, x) = A \ x
-
-jacobian(A::AbstractMatrix) = ConstantMap{glm_domaintype(A)}(A)
-jacobian(A::AbstractMatrix, x) = A
-
-canonicalmap(A::AbstractArray) = Map(A)
-canonicalmap(::Equal, A::AbstractArray) = Map(A)
-
 
 
 
@@ -618,10 +592,68 @@ convert(::Type{Map{SVector{N,T}}}, m::VectorAffineMap) where {N,T} =
     StaticAffineMap{T,N}(m.A, m.b)
 
 
+##############################
+# Numbers and arrays as a map
+##############################
+
+# Arrays represent the linear map A*x
+MapStyle(::Type{<:AbstractArray}) = IsMap()
+
+Map(A::AbstractArray) = LinearMap(A)
+Map{T}(A::AbstractArray) where T = LinearMap{T}(A)
+
+domaintype(A::AbstractArray) = domaintype(Map(A))
+
+applymap(A::AbstractArray, x) = A*x
+mapsize(A::AbstractArray) = size(A)
+
+islinearmap(A::AbstractArray) = true
+isaffinemap(A::AbstractArray) = true
+affinematrix(A::AbstractArray) = A
+affinevector(A::AbstractArray) = zerovector(A)
+
+inverse(A::AbstractMatrix) = inv(A)
+inverse(A::AbstractMatrix, x) = A \ x
+
+jacobian(A::AbstractMatrix) = ConstantMap{glm_domaintype(A)}(A)
+jacobian(A::AbstractMatrix, x) = A
+
+canonicalmap(A::AbstractArray) = Map(A)
+canonicalmap(::Equal, A::AbstractArray) = Map(A)
+
+# Numbers represent the linear map a*x
+
+MapStyle(::Type{<:Number}) = IsMap()
+
+applymap(a::Number, x) = a*x
+
+Map(a::Number) = LinearMap(a)
+Map{T}(a::Number) where T = LinearMap{T}(a)
+domaintype(a::Number) = typeof(a)
+
+mapsize(a::Number) = ()
+
+islinearmap(a::Number) = true
+isaffinemap(a::Number) = true
+affinematrix(a::Number) = a
+affinevector(a::Number) = zero(a)
+
+inverse(a::Number) = inv(a)
+inverse(a::Number, x) = a \ x
+
+jacobian(a::Number) = ConstantMap(a)
+jacobian(a::Number, x) = a
+
+canonicalmap(a::Number) = Map(a)
+canonicalmap(::Equal, a::Number) = Map(a)
+
+
 ###########################
 # Uniform scaling as a map
 ###########################
 
+MapStyle(::Type{<:UniformScaling}) = IsMap()
+
 convert(::Type{Map}, A::UniformScaling) = GenericLinearMap{Vector{Any}}(A)
 convert(::Type{Map{T}}, A::UniformScaling) where {T} = GenericLinearMap{T}(A)
 

src/util/common.jl

@@ -2,6 +2,7 @@
 isrealtype(::Type{<:Real}) = true
 isrealtype(::Type{<:Complex}) = false
 isrealtype(::Type{T}) where {T} = isrealtype(eltype(T))
+isrealtype(::Type{Any}) = false
 
 const StaticTypes = Union{Number,<:StaticVector{N} where N,<:NTuple{N,Any} where N}
 

test/test_common.jl

@@ -84,6 +84,15 @@ function test_numtype()
     @test promote_numtype(2, 3.0+im, big(4)) isa Tuple{Complex{BigFloat},Complex{BigFloat},Complex{BigFloat}}
 end
 
+using FunctionMaps: isrealtype
+
+function test_realtype()
+    @test isrealtype(Any) == false
+    @test isrealtype(Int) == true
+    @test isrealtype(ComplexF64) == false
+    @test isrealtype(Matrix{Float64}) == true
+end
+
 @testset "common functionality" begin
     @testset "dimension" begin
         test_dimension()
@@ -94,4 +103,6 @@ end
     @testset "numtype" begin
         test_numtype()
     end
+
+    test_realtype()
 end

test/test_interface.jl

@@ -3,9 +3,9 @@ struct MySimpleMap end
 FunctionMaps.MapStyle(::Type{MySimpleMap}) = IsMap()
 
 @testset "map interface" begin
-    @test MapStyle(2.0) isa NotMap
+    @test_throws ArgumentError checkmap((5,))   # a tuple is not a map
+    @test MapStyle(2.0) isa IsMap
     @test MapStyle(2.0) == MapStyle(typeof(2.0))
-    @test_throws ArgumentError checkmap(2.0)
     m = LinearMap(2)
     @test MapStyle(m) isa IsMap
     @test functionmap(m) === m