JacobiMethod

#include <iostream>
#include <cstdlib>

using namespace std;

class Jacobi{
private:
    float a[10][10], b[10], x[10];
    int n;
public:
    Jacobi(float x[10][10], float b1[10], int m);
    void jacobi();
    void display();
};

Jacobi::Jacobi(float x[10][10], float b1[10], int m){
    int i, j;
    n = m;
    for(i = 0; i < n; i++){
        for(j = 0; j < n; j++)
            a[i][j] = x[i][j];
        b[i] = b1[i];
    }
}

void Jacobi::jacobi(){
    float s;
    float xg[10], e[10], eps;
    int i, j, k, itr, flag;

    flag = 0;
    itr = 0; // itr = number of iterations
    eps = 1e-6; // eps = lowest value of difference of two consecutive roots

    // To initialize guess values
    for(i = 0; i < n; i++){
        xg[i] = 0;
    }
    // Jacobi iteration starts
    while(flag == 0){
        // Assuming convergence is reached
        flag = 1;
        itr = itr + 1;
        for(i = 0; i < n; i++){
            s = 0;
            for(j = 0; j < n; j++)
                if(i != j){
                    // For Jacobi
                    s = s + a[i][j] * xg[j];
                }
            x[i] = (b[i] - s) / a[i][i];
            e[i] = x[i] - xg[i];
            if(e[i] < 0)
                e[i] = -e[i];
        }
            // To check value of e[]
            for(i = 0; i < n; i++)
                if(e[i] > eps){
                    flag = 0;
                    break;
                }
            // To change guess values
            for(i = 0; i < n; i++){
                xg[i] = x[i];
            }
        }
    cout << "\nTotal number of Iterations taken  = " << itr << endl;
    display();
}

void Jacobi::display(){
    int i;
    cout << "Solutions of Linear Simultaneous Equations: \n";
    for(i = 0; i < n; i++){
        cout << "x[" << i + 1 << "] = " << x[i] << endl;
    }
}

int main(void) {
    system("cls");
    float a[10][10], b[10];
    int i, j, n;
    cout << "Enter the number of simultaneous equations(1-10): ";
    cin >> n;
    cout << "Enter the coefficients of all equations\n";
    for(i = 0; i < n; i++){
        for(j = 0; j < n; j++){
            cout << "a[" << i << "][" << j << "] = ";
            cin >> a[i][j];
        }
        cout << "b[" << i << "] = ";
        cin >> b[i];
    }
    Jacobi J(a, b, n);
    J.jacobi();
    return 0;
}