From 982a545bb3a5166de9fe052161bcac4a4964fcea Mon Sep 17 00:00:00 2001
From: Marshall Lochbaum <mwlochbaum@gmail.com>
Date: Mon, 7 Feb 2022 17:07:43 -0500
Subject: More FFT performance improvements

---
 fft.bqn | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/fft.bqn b/fft.bqn
index 735e92a..c735dc5 100644
--- a/fft.bqn
+++ b/fft.bqn
@@ -13,8 +13,8 @@ Sin‿Cos ← •math
   "FFT length must be a power of two" ! ⌊⊸=n
   s ← 2 ⥊˜ n
 
-  r ← (Cos≍Sin) π × (1↓s) ⥊ -⍟inv ↕⊸÷ l÷2   # Roots of unity
-  M ← -˝∘× ≍ +˝∘×⟜⌽                         # Complex multiplication
-  F ← { 𝕨 ⊏⎉1⊸𝕊⍟(1<=𝕨) (=𝕨)⍉(+˝˘≍𝕨M-˝˘)𝕩 } # FFT loop
-  ÷⟜l⍟inv ⥊˘ r F s⊸⥊˘ ≍⟜(0¨)⍟(1==) 𝕩
+  r ← (Cos⋈Sin) π × (1↓s) ⥊ -⍟inv ↕⊸÷ l÷2   # Roots of unity
+  M ← -´∘× ⋈ +´∘×⟜⌽                         # Complex multiplication
+  F ← { (r (2‿0<⊸«𝕨⥊1)⊸/¨↩) ⊢ (+˝¨(𝕨⍉≍)¨r M-˝¨)𝕩 } # FFT loop
+  ÷⟜l⍟inv >⥊¨ (↕n) F´˜ s⊸⥊¨ (1==)◶⟨<˘,⊢⋈0¨⟩ 𝕩
 }
-- 
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