imag for operators (#841)

* imag for operators

* implement conj

* Move real/imag to ApproxFunBase

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "ApproxFun"
 uuid = "28f2ccd6-bb30-5033-b560-165f7b14dc2f"
-version = "0.13.10"
+version = "0.13.11"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"
@@ -20,7 +20,7 @@ SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 
 [compat]
 AbstractFFTs = "1.0"
-ApproxFunBase = "0.7"
+ApproxFunBase = "0.7.29"
 ApproxFunBaseTest = "0.1"
 ApproxFunFourier = "0.3"
 ApproxFunOrthogonalPolynomials = "0.5"

src/ApproxFun.jl

@@ -60,7 +60,7 @@ import FFTW: plan_r2r!, fftwNumber, REDFT10, REDFT01, REDFT00, RODFT00, R2HC, HC
 
 import Base: values, convert, getindex, setindex!, *, +, -, ==, <, <=, >, |, !, !=, eltype, iterate,
                 >=, /, ^, \, ∪, transpose, size, tail, broadcast, broadcast!, copyto!, copy, to_index, (:),
-                similar, map, vcat, hcat, hvcat, show, summary, stride, sum, cumsum, sign, imag, conj, inv,
+                similar, map, vcat, hcat, hvcat, show, summary, stride, sum, cumsum, sign, conj, inv,
                 complex, reverse, exp, sqrt, abs, abs2, sign, issubset, values, in, first, last, rand, intersect, setdiff,
                 isless, union, angle, join, isnan, isapprox, isempty, sort, merge, promote_rule,
                 minimum, maximum, extrema, argmax, argmin, findmax, findmin, isfinite,

src/Extras/ReImSpace.jl

@@ -1,34 +1 @@
-
-
-
-## just takes realpart of operator
-struct ReOperator{O,T} <: Operator{T}
-    op::O
-end
-
-ReOperator(op)=ReOperator{typeof(op),Float64}(op)
-convert(::Type{Operator{T}},R::ReOperator) where {T} = ReOperator{typeof(R.op),T}(R.op)
-
-@wrapperstructure ReOperator
-@wrapperspaces ReOperator
-
-
-
-
-
-getindex(RI::ReOperator{O,T},k::Integer,j::Integer) where {O,T} =
-    convert(T,real(RI.op[k,j]))
-
-choosedomainspace(R::ReOperator,sp::Space) = choosedomainspace(R.op,sp)
-for OP in (:promotedomainspace,:promoterangespace)
-    @eval begin
-        $OP(R::ReOperator,sp::UnsetSpace) = ReOperator($OP(R.op,sp))
-        $OP(R::ReOperator,sp::Space) = ReOperator($OP(R.op,sp))
-    end
-end
-
-
-
-# TODO: can't do this because UnsetSpace might change type
-#real{T<:Real}(op::Operator{T})=op
-real(op::Operator) = ReOperator(op)
+real(op::Operator) = ApproxFunBase.real(op)

test/ExtrasTest.jl

@@ -136,4 +136,15 @@ using DualNumbers
         @test cumsum(d).J*Fun() ≈ Fun(x -> (x^2-1)/2)
         @test cumsum(d*d).J*Fun(1) ≈ cumsum(2d).f ≈ Fun(x -> x^2-1)
     end
+
+    @testset "real-imag" begin
+        A = (3 + 2im) * I : Chebyshev()
+        @test real(A)[1:4, 1:4] == diagm(0=>fill(3,4))
+        @test imag(A)[1:4, 1:4] == diagm(0=>fill(2,4))
+        @test conj(A)[1:4, 1:4] == conj(A[1:4, 1:4])
+        A = (3 - 2im) * I : Chebyshev()
+        @test real(A)[1:4, 1:4] == diagm(0=>fill(3,4))
+        @test imag(A)[1:4, 1:4] == diagm(0=>fill(-2,4))
+        @test conj(A)[1:4, 1:4] == conj(A[1:4, 1:4])
+    end
 end