不韋 呂
FFT for real data using decimation-in-frequency algorithm. 実データに対するFFT．周波数間引きアルゴリズムを使用． このライブラリを登録した際のプログラム： Demo_FFT_IFFT
Dependents: UIT2_SpectrumAnalyzer F746_SpectralAnalysis_NoPhoto F746_FFT_Speed F746_RealtimeSpectrumAnalyzer ... more
Diff: fftReal.hpp
- Revision:
- 0:982a9acf3a07
- Child:
- 1:559a63853f3f
--- /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