public class Approximator {

    double a[];
    double sumB[];
    double x[];
    double y[];
    double sumMatrix[][];
    int K;

    public Approximator(double x[], double y[]) {
        this.x = x;
        this.y = y;
        K = this.x.length-1;
        a = new double[K];
        sumB = new double[K];
        sumMatrix = new double[K][K];
    }

    public double[] getApprox() {
        for (int i = 0; i < K; i++) {
            System.out.println();
            for (int j = 0; j < K; j++) {
                for (int k = 0; k < K; k++) {
                    sumMatrix[i][j] += Math.pow(x[k], i + j);
                }
                System.out.print(sumMatrix[i][j] + " ");
            }
        }
        System.out.println();
        for (int i = 0; i < K; i++) {
            for (int k = 0; k < K; k++) {
                sumB[i] += Math.pow(x[k], i) * y[i];
            }
            System.out.print(sumB[i] + " ");
        }
        System.out.println();
        GaussMethod gm = new GaussMethod(sumMatrix, sumB);
        double solution[] = gm.getSolution();
        return solution;
    }
}