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法律研究直接计算 DFT 系数的 C++ 程序
在离散傅立叶变换 (DFT) 中，一个有限列表将函数中的等距采样转换为一个有限复数正弦波组合的系数列表。它们按各自的频率进行排序，即具有相同的采样值，以便将采样函数从其原始域（通常沿着直线的时间或位置）转换为频域。
算法
Begin
Declare three variables which are the coefficient of linear equation and max value
Read the variables
Define a class with two variables real, img
Create a constructor and set real, img to zero
Take a variable M and initialize it to some integer
Create function[M]
For i=0 to M do
function[i] = (((a * (double) i) + (b * (double) i)) - c)
Declare function sine[M]
Declare function cosine[M]
for i = 0 to M do
cosine[i] = cos((2 * i * k * PI) / M)
sine[i] = sin((2 * i * k * PI) / M)
for i = 0 to M do
dft_value.real += function[i] * cosine[i]
dft_value.img += function[i] * sine[i]
Print the value
End示例代码
#include<iostream>
#include<math.h>
using namespace std;
#define PI 3.14159265
class DFT_Coeff {
public:
double real, img;
DFT_Coeff() {
real = 0.0;
img = 0.0;
}
};
int main(int argc, char **argv) {
int M = 10;
cout << "Enter the coeff of simple linear function:\n";
cout << "ax + by = c\n";
double a, b, c;
cin >> a >> b >> c;
double function[M];
for (int i = 0; i < M; i++) {
function[i] = (((a * (double) i) + (b * (double) i)) - c);
}
cout << "Enter the max K value: ";
int k;
cin >> k;
double cosine[M];
double sine[M];
for (int i = 0; i < M; i++) {
cosine[i] = cos((2 * i * k * PI) / M);
sine[i] = sin((2 * i * k * PI) / M);
}
DFT_Coeff dft_value;
cout << "The coeffs are: ";
for (int i = 0; i < M; i++) {
dft_value.real += function[i] * cosine[i];
dft_value.img += function[i] * sine[i];
}
cout << "(" << dft_value.real << ") - " << "(" << dft_value.img << " i)";
}输出
Enter the coeff of simple linear function: ax + by = c 4 6 7 Enter the max K value: 4 The coeffs are: (-50) - (-16.246 i)
更新于： 30-Jul-2019
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