请用C语言实现上述代码的功能
时间: 2024-01-08 09:02:40 浏览: 27
以下是用C语言实现上述代码功能的示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#define N 403
void calculateParams(float *M, float *e, float *Theta, float *P) {
float x[9] = {0, 1, 0, 1, 1, 0, 1, 1, 1};
float v[N - 3];
float z[N];
float Pstore[4][N - 4];
// Generate input data sequence x
for (int i = 0; i < N; i++) {
int temp = x[3] ^ x[8];
M[i] = x[8];
for (int j = 8; j >= 2; j--) {
x[j] = x[j - 1];
}
x[1] = temp;
}
// Generate noise sequence v
for (int i = 0; i < N - 3; i++) {
v[i] = (float)rand() / RAND_MAX;
}
// Generate noise sequence e
e[0] = 0.3;
e[1] = 0.5;
for (int i = 2; i < N - 3; i++) {
e[i] = v[i] + 0.5 * v[i - 1] + 0.2 * v[i - 2];
}
// Initialize parameters
z[0] = -1;
z[1] = 0;
Theta[0] = Theta[1] = Theta[2] = Theta[3] = 3;
P[0] = P[5] = P[10] = P[15] = 100;
// Calculate parameters using two-step estimation
for (int i = 2; i < N - 1; i++) {
z[i] = -2 * z[i - 1] - 3 * z[i - 2] + 4 * M[i - 1] + 5 * M[i - 2] + e[i];
float h[4] = {-z[i - 1], -z[i - 2], M[i - 1], M[i - 2]};
float hstar[4] = {M[i - 1], M[i - 2], M[i - 3], M[i - 4]};
float K[4];
float hTPhstar = 0;
for (int j = 0; j < 4; j++) {
hTPhstar += h[j] * P[j * 5 + j] * hstar[j];
}
for (int j = 0; j < 4; j++) {
K[j] = P[j * 5 + j] * hstar[j] / (hTPhstar + 1);
Theta[j] += K[j] * (z[i] - h[0] * Theta[0] - h[1] * Theta[1] - h[2] * Theta[2] - h[3] * Theta[3]);
P[j * 5 + j] *= (1 - K[j] * h[0]) * (1 - K[j] * h[0]);
for (int k = 0; k < 4; k++) {
if (k != j) {
P[j * 5 + k] = P[j * 5 + k] - K[j] * h[k] * P[k * 5 + k];
P[k * 5 + j] = P[j * 5 + k];
}
}
}
for (int j = 0; j < 4; j++) {
Pstore[j][i - 1] = P[j * 5 + j];
}
}
// Output parameter estimates
printf("参数 a1 a2 b1 b2 估计结果:\n");
for (int i = 0; i < 4; i++) {
printf("%f ", Theta[i]);
}
printf("\n");
// Plot estimated parameters transition process
printf("待估参数过渡过程:\n");
for (int i = 0; i < N - 1; i++) {
printf("%d %f %f %f %f\n", i, Theta[0], Theta[1], Theta[2], Theta[3]);
}
// Plot variance change process
printf("估计方差变化过程:\n");
for (int i = 0; i < N - 4; i++) {
printf("%d %f %f %f %f\n", i, Pstore[0][i], Pstore[1][i], Pstore[2][i], Pstore[3][i]);
}
}
int main() {
float M[N];
float e[N - 3];
float Theta[4];
float P[4][4];
calculateParams(M, e, Theta, (float *)P);
return 0;
}
```
请注意,该示例代码仅用于实现上述功能,可能还需要根据具体的需求进行进一步调整和优化。希望对你有帮助!如果还有其他问题,请继续提问。