code: public void savePCAToFile(String PCAFileName) throws Exception {
  		if (isPcaInitialized) {
  			throw new Exception("Cannot save, PCA is initialized!");
  		}
  		if (V_t == null) {
  			throw new Exception("Cannot save to file, PCA matrix is null!");
  		}
  		BufferedWriter out = new BufferedWriter(new FileWriter(PCAFileName));
  		// the first line of the file contains the training sample means per component
  		for (int i = 0; i < sampleSize - 1; i++) {
  			out.write(means.get(i) + " ");
  		}
  		out.write(means.get(sampleSize - 1) + "\n");
  
  		// the second line of the file contains the eigenvalues in descending order
  		for (int i = 0; i < numComponents - 1; i++) {
  			out.write(W.get(i, i) + " ");
  		}
  		out.write(W.get(numComponents - 1, numComponents - 1) + "\n");
  
  		// the next lines of the file contain the eigenvectors in descending eigenvalue order
  		for (int i = 0; i < numComponents; i++) {
  			for (int j = 0; j < sampleSize - 1; j++) {
  				out.write(V_t.get(i, j) + " ");
  			}
  			out.write(V_t.get(i, sampleSize - 1) + "\n");
  		}
  		out.close();
  	}
docs: Writes the means, the eigenvalues and the PCA matrix to a text file. The 1st row of the file contains
  the training sample means per component, the 2nd row contains the eigenvalues in descending order and
  subsequent rows contain contain the eigenvectors in descending eigenvalue order.
  
  @param PCAFileName
  the PCA file
  @throws Exception