idw.cpp

反距离加权内插算法

// 输入输出.cpp : 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>   
#include <vector>
#include <math.h>

using namespace std;

class Point
{
public:
	double X;
	double Y;
	double Z;
};

int GetSourceData (vector<Point>& TPoint , string sFilefullname)
{
	cout << "正在读取已知点数据..." << endl;
	string tmpLine;
	string::size_type pos = 0, pre_pos = 0;
	ifstream infile(sFilefullname.c_str());
	Point vfTemp;
	if (!infile) {
		cerr << "unable to open input file: ";
		cin >> tmpLine;
		return -1;
	}
	while(getline(infile,tmpLine,'\n'))
	{
		pos = tmpLine.find_first_of(',');
		vfTemp.X = atof(tmpLine.substr(0, pos).c_str());
		pre_pos = ++pos;
		pos = tmpLine.find_first_of(',',pos);
		vfTemp.Y = atof(tmpLine.substr(pre_pos, pos - pre_pos).c_str());
		pre_pos = ++pos;
		vfTemp.Z = atof(tmpLine.substr(pos).c_str());
		TPoint.push_back(vfTemp);
		pos = 0;
	}

	return 0;
}

int GetTargetData (vector<Point>& TPoint , string sFilefullname)
{
	cout << "正在读取目标点数据..." << endl;
	string tmpLine;
	string::size_type pos = 0, pre_pos = 0;
	ifstream infile(sFilefullname.c_str());
	Point vfTemp;
	if (!infile) {
		cerr << "unable to open input file: ";
		cin >> tmpLine;
		return -1;
	}
	while(getline(infile,tmpLine,'\n'))
	{
		pos = tmpLine.find_first_of(',');
		vfTemp.X = atof(tmpLine.substr(0, pos).c_str());
		pre_pos = ++pos;
		vfTemp.Y = atof(tmpLine.substr(pos).c_str());
		vfTemp.Z = -9999;
		TPoint.push_back(vfTemp);
		pos = 0;
	}

	return 0;
}



int interpolation (vector<Point>& TPoint, vector<Point>& SPoint)
{
	cout << "正在进行内插计算..." << endl;
	int i = 0,j,k = 0,l;
	double sum1 =0.,sum2=0.;
	k = TPoint.size();
	i = SPoint.size();
	double d;
	for (l = 0;l < k;l++){
		for(j = 0;j < i;j++){
			d = sqrt((TPoint[l].X-SPoint[j].X)*(TPoint[l].X-SPoint[j].X)+(TPoint[l].Y-SPoint[j].Y)*(TPoint[l].Y-SPoint[j].Y));
			if(d < 70.7){
				sum1 += SPoint[j].Z/(d*d);
				sum2 += 1/(d*d);
				}
			}
		TPoint[l].Z=sum1/sum2;
		cout<<TPoint[l].Z<<endl;
		sum1 = 0;
		sum2 = 0;
	}//...内插算法
	
	return 0;
}

int _tmain(int argc, _TCHAR* argv[])
{
	string sTargetfullname("target.txt");
	string sSourcefullname("source.txt");
	string sParafullname("para.txt");
	string sResultfullname("result.txt");
	vector<Point> TPoint; //目标点坐标及属性数组
	vector<Point> SPoint; //已知点坐标及属性数组
	vector<Point> PARA;
	int error;

	ofstream info("info.txt", ios::app);

	if (!info) {
		return -1;
	}

	error = GetTargetData(TPoint, sTargetfullname);

	if (error == -1)
	{
		info << "false" << endl << "目标点坐标文件无法打开";
		return -1;
	}

	error = GetSourceData(SPoint, sSourcefullname);

	if (error == -1)
	{
		info << "false" << endl << "已知点坐标文件无法打开";
		return -1;
	}


	error = interpolation(TPoint, SPoint);
	
	if (error == -1)
	{
		info << "false" << endl << "内插过程失败";
		return -1;
	}

	ofstream ofResult(sResultfullname.c_str());

	int i = 0;
	int j = TPoint.size();
	while (i < j)
	{
		ofResult << TPoint[i].X << ',' << TPoint[i].Y << ',' << TPoint[i].Z << endl;
		if (TPoint[i].Z == -9999)
		{
			info << "false" << endl << "内插计算出现错误，结果输出中断" << endl;
			return -1;
		}
		i = i + 1;
	}
	info << "ture" << endl ;
}