Merge pull request #44 from jishnub/broadcast

Lazy broadcasting for Frequencies

Author: stevengj

src/definitions.jl

@@ -415,6 +415,12 @@ Base.step(x::Frequencies) = x.multiplier
 
 Base.copy(x::Frequencies) = x
 
+# Retain the lazy representation upon scalar multiplication
+Broadcast.broadcasted(::typeof(*), f::Frequencies, x::Number) = Frequencies(f.n_nonnegative, f.n, f.multiplier * x)
+Broadcast.broadcasted(::typeof(*), x::Number, f::Frequencies) = Broadcast.broadcasted(*, f, x)
+Broadcast.broadcasted(::typeof(/), f::Frequencies, x::Number) = Frequencies(f.n_nonnegative, f.n, f.multiplier / x)
+Broadcast.broadcasted(::typeof(\), x::Number, f::Frequencies) = Broadcast.broadcasted(/, f, x)
+
 """
     fftfreq(n, fs=1)
 Return the discrete Fourier transform (DFT) sample frequencies for a DFT of length `n`. The returned

test/runtests.jl

@@ -101,6 +101,19 @@ end
     @test eltype(fftfreq(5, ComplexF64(2))) == ComplexF64
 
     @test_throws ArgumentError Frequencies(12, 10, 1)
+
+    @testset "scaling" begin
+        @test fftfreq(4, 1) * 2 === fftfreq(4, 2)
+        @test fftfreq(4, 1) .* 2 === fftfreq(4, 2)
+        @test 2 * fftfreq(4, 1) === fftfreq(4, 2)
+        @test 2 .* fftfreq(4, 1) === fftfreq(4, 2)
+
+        @test fftfreq(4, 1) / 2 === fftfreq(4, 1/2)
+        @test fftfreq(4, 1) ./ 2 === fftfreq(4, 1/2)
+
+        @test 2 \ fftfreq(4, 1) === fftfreq(4, 1/2)
+        @test 2 .\ fftfreq(4, 1) === fftfreq(4, 1/2)
+    end
 end
 
 @testset "normalization" begin