请用c++帮我实现matlab的contourc函数,并且不使用opencv
时间: 2024-03-21 14:42:03 浏览: 27
contourc函数的作用是计算等值线数据,返回一个矩阵,其中包含等值线的坐标和属性。在C++中可以使用以下代码实现:
```c++
#include <iostream>
#include <vector>
#include <cmath>
using namespace std;
struct Point {
double x, y;
};
vector<vector<Point>> contourc(vector<vector<double>>& data, double level) {
int rows = data.size();
int cols = data[0].size();
vector<vector<int>> visited(rows, vector<int>(cols, 0));
vector<vector<Point>> contours;
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
if (visited[i][j] == 0 && data[i][j] > level) {
vector<Point> contour;
Point p = {j, i};
contour.push_back(p);
visited[i][j] = 1;
int x = j;
int y = i;
int dx = 0;
int dy = -1;
while (true) {
int nx = x + dx;
int ny = y + dy;
if (nx < 0 || nx >= cols || ny < 0 || ny >= rows || visited[ny][nx] == 1) {
dx = dy;
dy = -nx;
nx = x + dx;
ny = y + dy;
if (nx < 0 || nx >= cols || ny < 0 || ny >= rows || visited[ny][nx] == 1) {
break;
}
}
Point np = {nx, ny};
contour.push_back(np);
visited[ny][nx] = 1;
x = nx;
y = ny;
}
contours.push_back(contour);
}
}
}
return contours;
}
int main() {
vector<vector<double>> data = {{1, 2, 3}, {2, 3, 4}, {3, 4, 5}};
double level = 3.5;
vector<vector<Point>> contours = contourc(data, level);
for (int i = 0; i < contours.size(); i++) {
cout << "Contour " << i << ": ";
for (int j = 0; j < contours[i].size(); j++) {
cout << "(" << contours[i][j].x << ", " << contours[i][j].y << ") ";
}
cout << endl;
}
return 0;
}
```
这个实现方法是基于扫描线法的,先找到第一个大于等于level的点,然后沿着等值线方向扫描,找到下一个点,直到回到起点。在扫描的过程中,需要判断边界和已经访问过的点。用一个visited矩阵来记录已经访问过的点。最后将每个等值线的点存储在一个vector中,所有的等值线存储在一个vector<vector<Point>>中返回。