From 876de6d793f0d27d5b2b245992cbb6b625fb9ad7 Mon Sep 17 00:00:00 2001
From: William Kearney <William.Kearney.ctr@nrlssc.navy.mil>
Date: Mon, 3 Aug 2020 10:42:41 -0500
Subject: [PATCH] Call the correct function for irfft(xs,d,dims)

Fixes #755
---
 src/lib/array.jl  | 8 ++++----
 test/gradcheck.jl | 8 +++-----
 2 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/src/lib/array.jl b/src/lib/array.jl
index 563e5076f..48b1c134f 100644
--- a/src/lib/array.jl
+++ b/src/lib/array.jl
@@ -931,16 +931,16 @@ end
 end
 
 @adjoint function irfft(xs, d, dims)
-  return AbstractFFTs.ifft(xs, dims), function(Δ)
+  return AbstractFFTs.irfft(xs, d, dims), function(Δ)
     dims = collect(dims)
     N = prod(collect(size(xs))[dims])
-    return (AbstractFFTs.rfft(Δ, dims)/N, nothing, nothing)
+    return (AbstractFFTs.rfft(real.(Δ), dims)/N, nothing, nothing)
   end
 end
 @adjoint function brfft(xs, d, dims)
-  return AbstractFFTs.ifft(xs, dims), function(Δ)
+  return AbstractFFTs.brfft(xs, d, dims), function(Δ)
     dims = collect(dims)
-    return (AbstractFFTs.rfft(Δ, dims), nothing, nothing)
+    return (AbstractFFTs.rfft(real.(Δ), dims), nothing, nothing)
   end
 end
 
diff --git a/test/gradcheck.jl b/test/gradcheck.jl
index b07837214..e120293d7 100644
--- a/test/gradcheck.jl
+++ b/test/gradcheck.jl
@@ -1453,8 +1453,7 @@ end
 
   x = randn(Float64,16,16)
   @test typeof(gradient(x->sum(abs2,ifft(fft(x,1),1)),x)[1]) == Array{Complex{Float64},2}
-  # This errors: something is the wrong size
-  #@test typeof(gradient(x->sum(abs2,irfft(rfft(x,1),16,1)),x)[1]) == Array{Float64,2} 
+  @test typeof(gradient(x->sum(abs2,irfft(rfft(x,1),16,1)),x)[1]) == Array{Float64,2} 
 
   x = randn(Float32,16)
   P = plan_fft(x)
@@ -1463,9 +1462,8 @@ end
   @test typeof(gradient(x->sum(abs2,irfft(rfft(x),16)),x)[1]) == Array{Float32,1}
 
   x = randn(Float32,16,16)
-  @test typeof(gradient(x->sum(abs2,ifft(fft(x,1),1)),x)[1]) == Array{Complex{Float32},2}
-  # This errors: something is the wrong size
-  #@test typeof(gradient(x->sum(abs2,irfft(rfft(x,1),16,1)),x)[1]) == Array{Float32,2}
+  @test typeof(gradient(x->sum(abs2,ifft(fft(x,1),1)),x)[1]) == Array{Complex{Float32},2}  
+  @test typeof(gradient(x->sum(abs2,irfft(rfft(x,1),16,1)),x)[1]) == Array{Float32,2}
 end
 
 @testset "FillArrays" begin