[GIS算法] DEM – 种子搜索法替换面属性 – C

【题目】种子搜索法替换面属性

【DEM文件】

8 10
2 2 3 4 6 7 7 3 2 2
5 6 7 4 5 1 2 5 7 9
1 2 2 1 1 1 1 7 9 0
3 2 1 1 1 1 6 9 9 7
3 2 1 1 1 1 1 3 7 8
4 5 6 7 1 1 2 3 5 8
1 0 0 9 8 8 9 2 4 7
3 2 2 1 6 9 0 1 5 0
4 3 5

【代码】

#include<stdio.h>
#include<stdlib.h>

typedef struct{
	double x0,y0; //左下角点的坐标值
	int dx,dy; //栅格单元大小
	int ycount,xcount; //行列号
	double **M; //矩阵
}DEM;

DEM* CreateDEM();
int InitDEM(FILE *fp, DEM *pDEM);
void PrintDEM(DEM dem);

double GetValue(DEM dem, int row, int col) {
	return dem.M[row][col];
}
// 说明：八连通区域
void Reclass(DEM *pDEM, int row, int col, double attr, double toAttr) {
	int i,j;
	int x,y;

	// 该位置不等于attr，退出
	if ( pDEM->M[row][col]!=attr ) return;
	// 超出范围，退出
	if (row<0 && row>pDEM->xcount && col<0 && col>pDEM->ycount) return ;
	// 扩散
	pDEM->M[row][col] = toAttr;
	for (i=-1; i<=1; i++) {
		for (j=-1; j<=1; j++) {
			x = row+i;
			y = col+j;
			Reclass(pDEM, x, y, attr, toAttr);
		}
	}
}

int main() {
	FILE *fp;
	DEM *pDEM;
	int row,col;
	double toAttr;

	fp = fopen("2018-7.txt", "r");
	printf("读取dem中...\n读取成功！\n");
	pDEM = CreateDEM(fp);
	InitDEM(fp, pDEM);
	PrintDEM(*pDEM);
	printf("\n");

	fscanf(fp, "%d%d%lf", &row, &col, &toAttr);
	printf("种子点(%d,%d)->颜色%lf （坐标描述规则：行、列）", row, col, toAttr);

	Reclass(pDEM, row, col, GetValue(*pDEM, row, col) ,toAttr);
	printf("\n重分类结果...\n");
	PrintDEM(*pDEM);
	

	
	fclose(fp);
	return 0;
}

DEM* CreateDEM(FILE *fp) {
	DEM *p;
	int i;
	p = (DEM *)malloc(sizeof(DEM)); if (!p) exit(0);
	fscanf(fp, "%d%d", &p->xcount, &p->ycount);
	p->M = (double **)malloc(sizeof(double *) * p->xcount); if (!p->M) exit(0);
	for (i=0; i<p->xcount; i++) {
		p->M[i] = (double *)malloc(sizeof(double)* p->ycount);
		if (!p->M[i]) exit(0);
	}
	return p;
}
int InitDEM(FILE *fp, DEM *pDEM) {
	int i,j;

	for (i=0; i<pDEM->xcount; i++) {
		for (j=0; j<pDEM->ycount; j++) {
			fscanf(fp, "%lf", &pDEM->M[i][j]); 
		}
	}
	return 1;
}
void PrintDEM(DEM dem) {
	int i,j;

	for (i=0; i<dem.xcount; i++) {
		for (j=0; j<dem.ycount; j++) {
			printf("%lf\t", dem.M[i][j]);
		}
		printf("\n");
	}
}

转载自：https://blog.csdn.net/summer_dew/article/details/84955075