Organize App class

unilectures/src/bxt/unilectures/algogis/leastsquares/App.java

@@ -2,7 +2,6 @@
 
 import java.util.Locale;
 import java.util.Scanner;
-import java.util.function.BiFunction;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
@@ -11,42 +10,29 @@
 
 public class App {
 
+	private static boolean USE_STDIN = false;
+
+	private static String EXAMPLE_INPUT = ""
+			+ "4\n"
+			+ "5\n"
+			+ "1 2 4.1 1\n"
+			+ "2 3 -7 1\n"
+			+ "3 4 1.1 1\n"
+			+ "4 1 1.2 1\n"
+			+ "4 2 5.4 1\n"
+			+ "\n"
+			+ "\n"
+			+ "\n"
+			;
+
 	public static void main(String[] args) {
-		String input = ""
-				+ "4\n"
-				+ "5\n"
-				+ "1 2 4.1 1\n"
-				+ "2 3 -7 1\n"
-				+ "3 4 1.1 1\n"
-				+ "4 1 1.2 1\n"
-				+ "4 2 5.4 1\n"
-				+ "\n"
-				+ "\n"
-				+ "\n"
-				;
-		Measurements m = scanMeasurements(new Scanner(input));
+		Scanner sc = USE_STDIN ? new Scanner(System.in) : new Scanner(EXAMPLE_INPUT);
 
-		LeastSquaresAdjustment l = m.getLeastSquaresAdjustment();
+		Measurements m = scanMeasurements(sc);
 
-		BiFunction<Integer, Matrix, String> printSqrtDiagonal = (n, x) ->
-			IntStream.range(0, n)
-				.mapToObj(i -> x.get(i, i))
-				.map(v -> Double.toString(Math.sqrt(v)))
-				.collect(Collectors.joining("\n"));
+		LeastSquaresAdjustment l = m.getLeastSquaresAdjustment();
 
-		Stream.of( "Least-squares estimates of heights:"
-		         , Util.matrixToString(l.getUnknowns())
-
-		         , "Corrected measurements:"
-		         , Util.matrixToString(l.getTrueObservations())
-
-		         , "Standard deviation of heights:"
-		         , printSqrtDiagonal.apply(m.getPointsSize()-1, l.getUnknownVariance())
-
-		         , "Standard deviation of measurements:"
-		         , printSqrtDiagonal.apply(m.getMeasurementsSize(), l.getObservationVariance())
-
-		         ).forEachOrdered(System.out::println);
+		printResults(m, l);
 	}
 
 	private static Measurements scanMeasurements(Scanner scanner) {
@@ -67,4 +53,27 @@ private static Measurements scanMeasurements(Scanner scanner) {
 		return maseurements;
 	}
 
+	private static void printResults(Measurements m, LeastSquaresAdjustment l) {
+		Stream.of( "Least-squares estimates of heights:"
+		         , Util.matrixToString(l.getUnknowns())
+
+		         , "Corrected measurements:"
+		         , Util.matrixToString(l.getTrueObservations())
+
+		         , "Standard deviation of heights:"
+		         , stringSqrtDiagonal(m.getPointsSize()-1, l.getUnknownVariance())
+
+		         , "Standard deviation of measurements:"
+		         , stringSqrtDiagonal(m.getMeasurementsSize(), l.getObservationVariance())
+
+		         ).forEachOrdered(System.out::println);
+	}
+
+	private static String stringSqrtDiagonal(int n, Matrix m) {
+		return IntStream.range(0, n)
+			.mapToObj(i -> m.get(i, i))
+			.map(v -> Double.toString(Math.sqrt(v)))
+			.collect(Collectors.joining("\n"));
+	}
+
 }