// Mike Scott // 2d array manipulation examples //import import java.awt.Color; public class FilterExample { /* *pre: image != null, image.length > 1, image[0].length > 1 * image is a rectangular matrix, neighberhoodSize > 0 *post: return a smoothed version of image */ public Color[][] smooth(Color[][] image, int neighberhoodSize) { //check precondition assert image != null && image.length > 1 && image[0].length > 1 && ( neighberhoodSize > 0 ) && rectangularMatrix( image ) : "Violation of precondition: smooth"; Color[][] result = new Color[image.length][image[0].length]; for(int row = 0; row < image.length; row++) { for(int col = 0; col < image[0].length; col++) { result[row][col] = aveOfNeighbors(image, row, col, neighberhoodSize); } } return result; } // helper method that determines the average color of a neighberhood // around a particular cell. private Color aveOfNeighbors(Color[][] image, int row, int col, int neighberhoodSize) { int numNeighbors = 0; int red = 0; int green = 0; int blue = 0; for(int r = row - neighberhoodSize; r <= row + neighberhoodSize; r++) { for(int c = col - neighberhoodSize; c <= col + neighberhoodSize; c++) { if( inBounds( image, r, c ) ) { numNeighbors++; red += image[r][c].getRed(); green += image[r][c].getGreen(); blue += image[r][c].getBlue(); } } } assert numNeighbors > 0; return new Color( red / numNeighbors, green / numNeighbors, blue / numNeighbors ); } import java.util.Scanner; public class ScannerAndKeyboard { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.print( "Enter your name: " ); String name = s.nextLine(); System.out.println( "Hello " + name + "!" ); } } /** * A class to provide a simple list of integers. * List resizes automatically. Used to illustrate * various design and implementation details of * a class in Java. * * Version 1 only contains the instance variables and * the constructors * @author scottm * */ public class IntListVer1 { // class constant for default size private static final int DEFAULT_CAP = 10; //instance variables private int[] iValues; private int iSize; /** * Default constructor. Creates an empty list. */ public IntListVer1(){ //redirect to single int constructor this(DEFAULT_CAP); //other statments could go here. } /** * Constructor to allow user of class to specify * initial capacity in case they intend to add a lot * of elements to new list. Creates an empty list. * @param initialCap > 0 */ public IntListVer1(int initialCap) { assert initialCap > 0 : "Violation of precondition. IntListVer1(int initialCap):" + "initialCap must be greater than 0. Value of initialCap: " + initialCap; iValues = new int[initialCap]; iSize = 0; } }