CPU_Conjugate.cpp

#include <iostream>
#include <cmath>
#include <algorithm>
#include <stdio.h>
#include <stdlib.h>
#include <fstream>
#include <cmath>
#include <sys/time.h>

using namespace std;
const double eps = 1e-6;

double VecMulVec(double *a, double *b, int N) {
	double ans = 0;
	for (int i = 0; i < N; i++) {
		ans += a[i] * b[i];
	}
	return ans;
}

void MatrixMulVec(double **a, double *b, double *r, int M, int N) {
	for (int i = 0; i < M; i++) {
		r[i] = 0;
		for (int k = 0; k < N; k++) {
			r[i] += a[i][k] * b[k];
		}
	}
}

int t = 0;

bool check(double *r, int N) {
	double res = 0;
	for (int i = 0; i < N; i++) {
		res += fabs(r[i]);
	}
	t++;
	/*if (t < 10) {
		for (int i = 0; i < N; i++)
			cout<<r[i]<<' ';
		cout<<endl;
		cout<<res<<endl;
	}*/
	if (res < eps) return true;
	else return false;
}

void solve(double **a, double *b, double *x, double *r, double *p, int M, int N) {
	for (int i = 0; i < N; i++) {
		x[i] = 0;
	}
	double *tmp, *nr;
	tmp = new double [M];
	nr = new double [M];
	MatrixMulVec(a, x, tmp, M, N);
	for (int i = 0; i < M; i++)
		r[i] = b[i] - tmp[i];
	for (int i = 0; i < M; i++)
		p[i] = r[i];
	int k = 0;
	while (true) {
		k++;
		MatrixMulVec(a, p, tmp, M, N);
		double alpha = VecMulVec(r, p, M) / VecMulVec(p, tmp, M);
		for (int i = 0; i < N; i++)
			x[i] += alpha * p[i];
		for (int i = 0; i < M; i++)
			nr[i] = r[i] - alpha * tmp[i];
		if (check(nr, M)) break;
		double beta = VecMulVec(nr, nr, M) / VecMulVec(r, r, M);
		for (int i = 0; i < M; i++)
			p[i] = nr[i] + beta * p[i];
		for (int i = 0; i < M; i++)
			r[i] = nr[i];
	}
	delete []tmp;
	delete []nr;
}

int main (int argc, char* argv[]){

	int M, N;

	string T, P, Db;
	M = atoi(argv[1]);
	N = M;

	double elapsedTime, elapsedTime2;
	timeval start, end, end2;

	if(argc > 2) {
		T = argv[2];
		if(argc > 3) {
			P = argv[3];
			if(argc > 4) {
				Db = argv[4];
			}
		}
	}
	
	double **a, *b, *x, *r, *p;
	a = new double *[M];
	b = new double [M];
	x = new double [N];
	r = new double [M];
	p = new double [M];
	
	for (int i = 0; i < M; i++) {
		a[i] = new double [N];
	}
	
	ifstream matrixfile("matrix");
	if(!(matrixfile.is_open())){
		cout<<"Error: file not found"<<endl;
		return 0;
	}
	for(int i = 0; i < M; i++){
		for(int j = 0; j < N; j++){
			matrixfile >> a[i][j];
		}
	}
	for(int i = 0; i < M; i++){
		matrixfile >> b[i];
	}
	matrixfile.close();
	
	gettimeofday(&start, NULL);
	solve(a, b, x, r, p, M, N);
	gettimeofday(&end, NULL);
	
	//Output time and iterations
	if(T == "-t" || P == "-t"){
		elapsedTime = (end.tv_sec - start.tv_sec) * 1000.0;
		elapsedTime += (end.tv_usec - start.tv_usec) / 1000.0;
		cout<<"Time: "<<elapsedTime<<" ms."<<endl<<endl;
	}


	// Output the matrixes for debug
	if(T == "-p" || P == "-p"){
		for (int i = 0; i < N; i++) {
			cout<<x[i]<<endl;
		}
	}

	//Generate files for debug purpouse
	if(Db == "-d" || T == "-d" || P == "-d"){
		ofstream Af;
		Af.open("cpu");
		for (int i = 0; i < N; i++) {
			Af<<x[i]<<endl;
		}
		Af.close();

	}
	for (int i = 0; i < M; i++) {
		delete []a[i];
	}
	delete []a;
	delete []b;
	delete []x;
	delete []r;
	delete []p;
	return 0;
}