Diff: fftReal.hpp

Revision:

0:982a9acf3a07

Child:

1:148bf3a521a0

Child:

2:559a63853f3f

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/fftReal.hpp	Fri Dec 19 12:10:34 2014 +0000
@@ -0,0 +1,46 @@
+//-------------------------------------------------------------------
+// FFT class for real data ---- Header
+//      This class can execute FFT and IFFT 
+// Copyright (c) 2014 MIKAMI, Naoki,  2014/12/19
+//-------------------------------------------------------------------
+
+#ifndef FFT_REAL_HPP
+#define FFT_REAL_HPP
+
+#include "mbed.h"
+#include <complex>  // requisite for complex
+
+namespace Mikami
+{
+    typedef complex<float> Complex; // define "Complex"
+
+    class FftReal
+    {
+    private:
+        const int   N_FFT_;
+        const float N_INV_;
+        
+        Complex*    wTable_;    // twiddle factor
+        uint16_t*   bTable_;    // for bit reversal
+        Complex*    u_;         // working area
+
+        // Processing except for last stage
+        void ExcludeLastTtage();
+        // Use for reordering of rit reversal in IFFT
+        int Index(int n) { return (N_FFT_-bTable_[n]); }
+
+        FftReal(const FftReal& );
+        FftReal& operator=(const FftReal& );
+
+    public:
+        // Constructor
+        explicit FftReal(int16_t n);
+        // Destructor
+        ~FftReal();
+        // Execute FFT
+        void Execute(const float x[], Complex y[]);
+        // Execute IFFT
+        void ExecuteIfft(const Complex y[], float x[]);
+    };
+}
+#endif  // FFT_REAL_HPP