comparison fft.cpp @ 11:977f541d6683

GPL and cosmetic changes

+/*
+    Harmonic sinusoidal modelling and tools
+
+    C++ code package for harmonic sinusoidal modelling and relevant signal processing.
+    Centre for Digital Music, Queen Mary, University of London.
+    This file copyright 2011 Wen Xue.
+
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+*/
 //---------------------------------------------------------------------------
 
 #include <string.h>
 #include <stdlib.h>
 #include "fft.h"

 double Atan2(double y, double x)
 {
   if (x==0 && y==0) return 0;
   else return atan2(y, x);
 }//Atan2
+
+/**
+  function Log2: Log2
+
+  Returns x for Log2(2^x) if x is integer.
+*/
+int Log2(int x)
+{
+  return floor(log(x)/log(2)+0.5);
+}//Log2
 
 /**
   function BitInv: inverse bit order of Value within an $Order-bit expression.
 
   In: integer Value smaller than 2^Order