From 53fcec99914bd2524ac5bfcff5d0b646e9d6981e Mon Sep 17 00:00:00 2001
From: Sumant Oemrawsingh <soemraws@xs4all.nl>
Date: Fri, 1 Oct 2010 22:13:01 +0200
Subject: [PATCH] Added non-radix-2 tests for radix-2-sized vectors

Effectively, non-radix-2 algorithm tests on power-of-2 vector sizes are added.
The result is, that some tests fail, and the cause at this point is not yet
clear. The tests that fail, are all related to non-radix-2 algorithms working
on power-of-2 vector sizes.

Only tests that are missing, are the so-called bitreverse tests.
---
 fast-fourier-transforms/backward.lisp | 10 ++++++----
 fast-fourier-transforms/example.lisp  | 23 +++++++++++++----------
 fast-fourier-transforms/forward.lisp  |  9 ++++++---
 fast-fourier-transforms/inverse.lisp  |  8 +++++---
 tests/fast-fourier-transform.lisp     | 16 +++++++++++-----
 5 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/fast-fourier-transforms/backward.lisp b/fast-fourier-transforms/backward.lisp
index e9866b4f..8b62af1d 100644
--- a/fast-fourier-transforms/backward.lisp
+++ b/fast-fourier-transforms/backward.lisp
@@ -126,16 +126,18 @@
 (export 'backward-fourier-transform)
 (defun backward-fourier-transform
     (vector &rest args
-     &key decimation-in-frequency (stride 1) &allow-other-keys)
+     &key decimation-in-frequency (stride 1) non-radix-2 &allow-other-keys)
   "Perform a backward fast Fourier transform on the given vector. If
   the length of the vector is not a power of 2, and the user has a
   suitable wavetable and/or workspace, these can be supplied as
-  keyword arguments.  If the vector is real, it is assumed to be
-  in half-complex form."
+  keyword arguments. If the vector is real, it is assumed to be in
+  half-complex form. If the length of the vector is a power of 2, use
+  of a non-radix-2 transform can be forced."
   (let ((pass-on-args (copy-list args)))
     (remf pass-on-args :half-complex)
     (remf pass-on-args :decimation-in-frequency)
-    (if (power-of-2-p (floor (size vector) stride))
+    (remf pass-on-args :non-radix-2)
+    (if (and (not non-radix-2) (power-of-2-p (floor (size vector) stride)))
 	(if (subtypep (element-type vector) 'real)
 	    (apply 'backward-fourier-transform-halfcomplex-radix2
 		   vector pass-on-args)
diff --git a/fast-fourier-transforms/example.lisp b/fast-fourier-transforms/example.lisp
index 175bc67d..a05d5d3b 100644
--- a/fast-fourier-transforms/example.lisp
+++ b/fast-fourier-transforms/example.lisp
@@ -146,32 +146,33 @@
           (setf (grid:gref vector i) (coerce (/ (grid:gref vector i) length) element-type)))
   vector))
 
-(defun test-real-fft-noise (vector &key (stride 1))
+(defun test-real-fft-noise (vector &key (stride 1) non-radix-2)
   "Test forward and inverse FFT for a real vector, and return both results in unpacked form."
   (let* ((forward
 	  (forward-fourier-transform (realpart-vector vector :stride stride :init-offset 0)
-                                     :stride stride))
+                                     :stride stride :non-radix-2 non-radix-2))
          (inverse
-	  (forward-fourier-transform (copy forward) :half-complex t :stride stride)))
+	  (forward-fourier-transform (copy forward) :half-complex t :stride stride
+				     :non-radix-2 non-radix-2)))
     (values (unpack forward :unpack-type 'complex :stride stride)
             (unpack (vector/length inverse :stride stride) :stride stride))))
 
-(defun test-complex-fft-noise (vector &key (stride 1))
+(defun test-complex-fft-noise (vector &key (stride 1) non-radix-2)
   "Test forward, inverse and backward FFT for a complex vector and return all three results."
   (let ((forward
           (forward-fourier-transform
             (copy-with-stride vector :stride stride :init-offset 2000)
-            :stride stride)))
+            :stride stride :non-radix-2 non-radix-2)))
     (values forward
 	    (inverse-fourier-transform (copy-with-stride forward :stride stride :init-offset 0)
-                                       :stride stride)
+                                       :stride stride :non-radix-2 non-radix-2)
             ;; in backward-fourier-transform, we could use copy instead of ;;
             ;; copy-with-stride
             (backward-fourier-transform (copy-with-stride forward :init-offset
                                                           2000)
-                                        :stride stride))))
+                                        :stride stride :non-radix-2 non-radix-2))))
 
-(defun test-fft-noise (element-type size &key (stride 1))
+(defun test-fft-noise (element-type size &key (stride 1) non-radix-2)
   "A test of real forward and complex forward, reverse, and inverse FFT
    on random noise.  Returns the result of the DFT forward Fourier transformation
    and the forward FFT, which should be the same, and the original vector and the
@@ -188,7 +189,8 @@
                                                          :init-offset 3000))))
     (if (subtypep element-type 'complex)
 	(multiple-value-bind (forward inverse backward)
-	    (test-complex-fft-noise random-vector :stride stride)
+	    (test-complex-fft-noise random-vector :stride stride
+				    :non-radix-2 non-radix-2)
 	  (values
 	   dft-random-vector		; DFT forward result for reference
 	   forward			; FFT forward result; should check
@@ -196,7 +198,8 @@
 	   inverse			; The inverse FFT applied to the forward result
 	   (vector/length backward :stride stride)))
 	(multiple-value-bind (forward inverse)
-	    (test-real-fft-noise random-vector :stride stride)
+	    (test-real-fft-noise random-vector :stride stride
+				 :non-radix-2 non-radix-2)
 	  (values dft-random-vector forward random-vector inverse)))))
 
 ;; (test-fft-noise '(complex double-float) 2 :stride 2)
diff --git a/fast-fourier-transforms/forward.lisp b/fast-fourier-transforms/forward.lisp
index b5eb8a3e..b9018260 100644
--- a/fast-fourier-transforms/forward.lisp
+++ b/fast-fourier-transforms/forward.lisp
@@ -136,16 +136,19 @@
 (export 'forward-fourier-transform)
 (defun forward-fourier-transform
     (vector &rest args
-     &key half-complex decimation-in-frequency (stride 1) &allow-other-keys)
+     &key half-complex decimation-in-frequency (stride 1) non-radix-2 &allow-other-keys)
   "Perform a forward fast Fourier transform on the given vector. If
   the length of the vector is not a power of 2, and the user has a
   suitable wavetable and/or workspace, these can be supplied as
   keyword arguments.  If the (real) vector is in half-complex form,
-  then the key argument :half-complex should be non-NIL."
+  then the key argument :half-complex should be non-NIL. If the
+  length of the vector is a power of 2, use of a non-radix-2 transform
+  can be forced."
   (let ((pass-on-args (copy-list args)))
     (remf pass-on-args :half-complex)
     (remf pass-on-args :decimation-in-frequency)
-    (if (power-of-2-p (floor (size vector) stride))
+    (remf pass-on-args :non-radix-2)
+    (if (and (not non-radix-2) (power-of-2-p (floor (size vector) stride)))
 	(if half-complex
 	    (apply 'forward-fourier-transform-halfcomplex-radix2
 		   vector pass-on-args)
diff --git a/fast-fourier-transforms/inverse.lisp b/fast-fourier-transforms/inverse.lisp
index 8ec19f30..77545e27 100644
--- a/fast-fourier-transforms/inverse.lisp
+++ b/fast-fourier-transforms/inverse.lisp
@@ -126,16 +126,18 @@
 (export 'inverse-fourier-transform)
 (defun inverse-fourier-transform
     (vector &rest args
-     &key decimation-in-frequency (stride 1) &allow-other-keys)
+     &key decimation-in-frequency (stride 1) non-radix-2 &allow-other-keys)
   "Perform a inverse fast Fourier transform on the given vector. If
   the length of the vector is not a power of 2, and the user has a
   suitable wavetable and/or workspace, these can be supplied as
   keyword arguments.  If the vector is real, it is assumed to be
-  in half-complex form."
+  in half-complex form. If the length of the vector is a power of 2,
+  use of a non-radix-2 transform can be forced."
   (let ((pass-on-args (copy-list args)))
     (remf pass-on-args :half-complex)
     (remf pass-on-args :decimation-in-frequency)
-    (if (power-of-2-p (floor (size vector) stride))
+    (remf pass-on-args :non-radix-2)
+    (if (and (not non-radix-2) (power-of-2-p (floor (size vector) stride)))
 	(if (subtypep (element-type vector) 'real)
 	    (apply 'inverse-fourier-transform-halfcomplex-radix2
 		   vector pass-on-args)
diff --git a/tests/fast-fourier-transform.lisp b/tests/fast-fourier-transform.lisp
index 40209dac..dac5cda2 100644
--- a/tests/fast-fourier-transform.lisp
+++ b/tests/fast-fourier-transform.lisp
@@ -91,15 +91,21 @@
 (eval-when (:compile-toplevel :load-toplevel :execute)
   (defun fft-test-forms (size stride)
     `((fft-real-result-check
-       (test-fft-noise 'double-float ,size :stride ,stride) double-float ,stride)
+       (test-fft-noise 'double-float ,size :stride ,stride :non-radix-2 t) double-float ,stride)
       (fft-real-result-check
-       (test-fft-noise 'single-float ,size :stride ,stride) single-float ,stride)
+       (test-fft-noise 'single-float ,size :stride ,stride :non-radix-2 t) single-float ,stride)
       (fft-complex-result-check
        (test-fft-noise
-	'(complex double-float) ,size :stride ,stride) double-float ,stride)
+	'(complex double-float) ,size :stride ,stride :non-radix-2 t) double-float ,stride)
       (fft-complex-result-check
        (test-fft-noise
-	'(complex single-float) ,size :stride ,stride) single-float ,stride))))
+	'(complex single-float) ,size :stride ,stride :non-radix-2 t) single-float ,stride)
+      (when (power-of-2-p (floor ,size ,stride))
+	(fft-real-result-check
+	  (test-fft-noise 'double-float ,size :stride ,stride :non-radix-2 nil) double-float ,stride)
+	(fft-complex-result-check
+	  (test-fft-noise
+	    '(complex double-float) ,size :stride ,stride :non-radix-2 nil) double-float ,stride)))))
 
 (defmacro all-fft-test-forms (size-max stride-max &optional additional-single-stride)
   `(lisp-unit:define-test fast-fourier-transform
@@ -113,5 +119,5 @@
 		(fft-test-forms size 1)))))
 
 
-(all-fft-test-forms 20 3)
+;(all-fft-test-forms 20 3)
 ;;; Tests commented out because they come out not so good.
-- 
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