移植bot4cj

bot4cj/src/cpp/fft.cpp

@@ -0,0 +1,80 @@
+#define _USE_MATH_DEFINES
+#include <cmath>
+#include <vector>
+#include "fft.h"
+#include "Matrix.hh"
+using namespace qing;
+
+
+
+void functf1d(float A[DN])
+{
+    unsigned long int i;
+    float dt, tt;
+    float p = 0.1;
+    float freq = 10.0;      // 10Hz
+    float fs = DN;     // 采样率65536Hz
+    
+    dt = 1.0 / fs;
+    
+    for(i = 0; i < DN; i++)
+    {
+        tt = (float)i * dt;
+        A[i] = sin(2.0 * M_PI * freq * tt) * p;  // 正弦波
+        //A[1][i] = 0.0;                           // 虚部为0
+    }
+}
+
+
+// 初始化FFT数组
+static void fft_init(float A[2][DN], Matrx<float>& M)
+{
+    for (int i = 0; i < DN; i++) {
+        float a =  M.witch(i, 0);
+        A[0][i] = a;
+        A[1][i] = 0;
+    }
+}
+
+// 计算FFT结果
+static void fft_result(std::vector<float>& R, float A[2][DN])
+{
+    for (int i = 0; i < DN/2; i++) {
+        float a = pow(A[0][i], 2) + pow(A[1][i], 2);
+        R[i] = sqrt(a) / (DN/2);
+        //std::cout << i << ":\t" << R[i] << std::endl; 
+    }
+}
+
+extern "C" {
+
+    // 生成正弦波
+#ifdef _WIN64
+    __declspec(dllexport) void* gen_wave()
+#else
+    void* gen_wave()
+#endif
+    {
+        std::vector<float> A(DN);
+        functf1d(A.data());
+        return (void *)new Matrx<float>(DN, 1, A);
+    }
+    
+    // 开始FFT
+#ifdef _WIN64
+    __declspec(dllexport) void* start_fft(void* M)
+#else
+    void* start_fft(void* M)
+#endif  
+    {
+        float A[2][DN];
+        std::vector<float> R(N);
+        fft_init(A, *(Matrx<float> *)M);
+        //fft1(A, 1);	// 复序列基2 FFT
+        fft1r1(A, 1);   // 单实序列
+        fft_result(R, A);
+        return (void*) new Matrx<float>(N/2, 1, R);
+    }
+
+}
+