compact show for Frequencies

Author: jishnub

src/definitions.jl

@@ -462,6 +462,13 @@ Base.maximum(f::Frequencies{T}) where T = (f.n_nonnegative - ifelse(f.multiplier
 Base.minimum(f::Frequencies{T}) where T = (f.n_nonnegative - ifelse(f.multiplier >= zero(T), f.n, 1)) * f.multiplier
 Base.extrema(f::Frequencies) = (minimum(f), maximum(f))
 
+function Base.show(io::IO, f::Frequencies)
+    r1 = 0:f.n_nonnegative-1
+    r2 = -f.n + f.n_nonnegative:-1
+    v = "[$r1;" * (isempty(r2) ? "" : " $r2") * "]"
+    print(io, "$v*$(step(f))")
+end
+
 """
     fftfreq(n, fs=1)
 Return the discrete Fourier transform (DFT) sample frequencies for a DFT of length `n`. The returned

test/runtests.jl

@@ -108,6 +108,22 @@ end
             check_extrema(freqs)
         end
     end
+
+    @testset "show" begin
+        for f in Any[fftfreq(6), fftfreq(7, 2), rfftfreq(5, 0.3), rfftfreq(4, 3)]
+            fnn = f.n_nonnegative
+            r1 = 0:fnn - 1
+            r2 = -length(f) + fnn:-1
+            v = [r1; r2] * step(f)
+            @test v ≈ f
+            s = repr(f)
+            if !isempty(r2) # fftfreq
+                @test s == "[$r1; $r2]*$(step(f))"
+            else # rfftfreq
+                @test s == "[$r1;]*$(step(f))"
+            end
+        end
+    end
 end
 
 @testset "normalization" begin