用C++写个双三次插值算法
时间: 2023-08-04 11:39:43 浏览: 61
好的,以下是用C++实现的双三次插值算法:
```c++
#include <iostream>
#include <vector>
#include <cmath>
using namespace std;
double bicubicInterpolation(double x, double y, const vector<vector<double>>& data) {
int nx = data.size();
int ny = data[0].size();
int i = floor(x);
int j = floor(y);
double u = x - i;
double v = y - j;
double f[4][4];
for (int di = 0; di < 4; di++) {
for (int dj = 0; dj < 4; dj++) {
int ni = i + di - 1;
int nj = j + dj - 1;
ni = max(0, min(ni, nx - 1));
nj = max(0, min(nj, ny - 1));
f[di][dj] = data[ni][nj];
}
}
double wx[4], wy[4];
for (int di = 0; di < 4; di++) {
double p = u * u * u;
double q = u * u;
wx[di] = (di == 0) ? p - 2 * q + u : -p + 2 * q - u;
}
for (int dj = 0; dj < 4; dj++) {
double p = v * v * v;
double q = v * v;
wy[dj] = (dj == 0) ? p - 2 * q + v : -p + 2 * q - v;
}
double result = 0;
for (int di = 0; di < 4; di++) {
for (int dj = 0; dj < 4; dj++) {
result += wx[di] * wy[dj] * f[di][dj];
}
}
return result;
}
int main() {
vector<vector<double>> data = {
{1, 2, 3, 4},
{5, 6, 7, 8},
{9, 10, 11, 12},
{13, 14, 15, 16}
};
double x = 1.5;
double y = 2.5;
double result = bicubicInterpolation(x, y, data);
cout << "Interpolated value at (" << x << ", " << y << ") is " << result << endl;
return 0;
}
```
这里假设已经有了一个二维数组`data`,表示待插值的数据。`bicubicInterpolation`函数接受两个坐标值和数据数组,返回插值结果。在函数内部,首先找到距离该坐标最近的4x4个点,然后根据双三次插值的公式计算出插值结果。该算法的时间复杂度为O(1)。
相关推荐
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![pdf](https://img-home.csdnimg.cn/images/20210720083512.png)
![zip](https://img-home.csdnimg.cn/images/20210720083736.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)
![](https://csdnimg.cn/download_wenku/file_type_ask_c1.png)