Fast Fourier transform: Difference between revisions

Content added Content deleted

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@@ Line 2,736: / Line 2,736: @@
         O       :   table   ;
         Odds    :   table   ;
-        R       :   table   ;
+        T       :   complex ;
-        T       :   table   ;
     BEGIN
@@ Line 2,751: / Line 2,750: @@
         SetLength ( E,    halfN )   ;
         SetLength ( O,    halfN )   ;
+        Split     ( L, E, O )       ;
+        SetLength ( L, 0 )   	    ;
         SetLength ( Even, halfN )   ;
+        Even :=     FFT ( E )       ;
+        SetLength ( E   , 0 )       ;
         SetLength ( Odds, halfN )   ;
-        Split     ( L, E, O )       ;
-        Even :=     FFT ( E )       ;
         Odds :=     FFT ( O )       ;
-        SetLength ( E   , 0 )       ;
         SetLength ( O   , 0 )       ;
-        SetLength ( R,    N )       ;
+        SetLength ( L,    N )       ;
-        SetLength ( T,    halfN )   ;
         FOR k := 0 to halfN - 1 DO
             BEGIN
-                T [ k ]         := Cexp ( -2 * i * pi * k / N ) * Odds [ k ];
+                T               := Cexp ( -2 * i * pi * k / N ) * Odds [ k ];
-                R [ k ]         := Even [ k ] + T [ k ]                     ;
+                L [ k ]         := Even [ k ] + T                      	    ;
-                R [ k + halfN ] := Even [ k ] - T [ k ]                     ;
+                L [ k + halfN ] := Even [ k ] - T                      	    ;
             END ;
-        SetLength ( T   , 0 )   ;
         SetLength ( Even, 0 )   ;
         SetLength ( Odds, 0 )   ;
-        FFT :=  R               ;
+        FFT :=  L               ;
-        SetLength ( R, 0 )      ;
     END ;
@@ Line 2,833: / Line 2,828: @@
 </lang>
-JPD 2021/12/24
+JPD 2021/12/26
 =={{header|Perl}}==