void Pca()
{
	FILE* fp;
	fp = fopen("pca2d.txt", "r");
	int n, d;
	fscanf(fp, "%d %d", &n, &d);
	printf("%d %d\n", n, d);
	Mat X(n, d, CV_64FC1);
	float c[7];

	for (int i = 0; i < n; i++)
	{
		fscanf(fp, "%f %f %f %f %f %f %f", &c[0], &c[1], &c[2], &c[3], &c[4], &c[5], &c[6]);
		for (int j = 0; j < d; j++)
		{
			X.at<double>(i, j) = c[j];
		}
	}
	double medie[7] = { 0 };
	for (int i = 0; i < d; i++)
	{
		for (int j = 0; j < n; j++)
		{
			medie[i] += X.at<double>(j, i);
		}
		medie[i] /= n;
	}


	for (int i = 0; i < d; i++)
	{
		for (int j = 0; j < n; j++)
		{
			X.at<double>(j,i) -= medie[i];
		}
	}
	//std::cout << X;
	printf("\n");

	fclose(fp);

	//calc matrice covarianta
	Mat C = X.t()*X / (n - 1);

	//descompunere in val propri
	Mat Lambda, Q;
	eigen(C, Lambda, Q);
	Q = Q.t();

	std::cout << "Lamba" << Lambda;

	//coef PCA
	Mat Coef = X*Q;

	int k= 1;
	Mat Coefk(n, k, CV_64FC1);
	Mat Qk(d, k, CV_64FC1);

	//aprox Xk
	for (int i = 0; i < d; i++)
	{
		for (int j = 0; j < k; j++)
		{
			Coefk.at<double>(i, j) = Coef.at<double>(i, j);
		}
	}

	for (int i = 0; i < d; i++)
	{
		for (int j = 0; j < k; j++)
		{
			Qk.at<double>(i, j) = Q.at<double>(i, j);
		}
	}

	//Qk trans
	Mat Qk_t = Qk.t();
	Mat XaproxK = X*Qk*Qk_t;
	//std::cout << XaproxK;


	double mediaDifAbs = 0;

	for (int i = 0; i < n; i++) {
		for (int j = 0; j < d; j++) {
			mediaDifAbs += abs(X.at<double>(i, j) - XaproxK.at<double>(i, j));
		}
	}
	mediaDifAbs /= n*d;
	printf("\nMedia dif Abs: %f", mediaDifAbs);

	//min si max
	double minCol, maxCol;
	for (int i = 0; i < d; i++)
	{
		minCol = Coef.at<double>(0,i);
		maxCol = Coef.at<double>(0, i);
		for (int j = 1; j < n; j++)
			{
				if (minCol > Coef.at<double>(j,i))
				{
					minCol = Coef.at<double>(j, i);
				}
				if (maxCol < Coef.at<double>(j, i))
				{
					maxCol = Coef.at<double>(j, i);
				}
			}
	}

	std::cout << "\nMinCol:  "<< minCol;
	std::cout << "\nMaxCol:  "<<  maxCol;

	waitKey(0);


}