Java examples for Collection Framework:Array Element
Generates an array going for a to b with steps of size step.
//package com.java2s; public class Main { /**/*w w w.j a v a 2 s . c o m*/ * Generates an array going for a to b * with steps of size step. If it can't * get to the value b in a finite number * of steps, it gets as close as possible * (a can be larger or smaller than b) * * @param step size of steps, must be positive. * @param a first value of array. * @param b last value of array. * @throws IllegalArgumentException if step is negative of if a=b. */ public static double[] range(double a, double b, double step) { if (step <= 0.0) { throw new IllegalArgumentException( "The argument step should be positive: " + step + " < 0"); } if (a == b) { double[] ans = new double[1]; ans[0] = a; return (ans); } int sizeOfArray = (new Double(Math.abs(a - b) / step)).intValue() + 1; double[] ans = new double[sizeOfArray]; ans[0] = a; if (a > b) { step = -step; } for (int k = 1; k < sizeOfArray; k++) { ans[k] = ans[k - 1] + step; } return (ans); } /** * Generates an array going for a to b * inclusively with steps of size 1. a can be * smaller or larger than b. */ public static double[] range(double a, double b) { return (range(a, b, 1.0)); } /** * returns the difference between the max and the min element */ public static double range(double[] population) { double min = Double.POSITIVE_INFINITY; double max = Double.NEGATIVE_INFINITY; for (int i = 0; i < population.length; i++) { if (population[i] < min) min = population[i]; if (population[i] > max) max = population[i]; } return max - min; } /** * Generates an array going for 0 to b * with steps of size 1. 0 can be * smaller or larger than b. */ public static double[] range(double b) { return (range(0, b)); } /** * Generates an array going for a to b * with steps of size 1. a can be * smaller or larger than b. */ public static int[] range(int a, int b) { return (range(a, b, 1)); } /** * Generates an array going for 0 to b * with steps of size 1. 0 can be * smaller or larger than b. */ public static int[] range(int b) { return (range(0, b)); } /** * Generates an array going for a to b * with steps of size step. If it can't * get to the value b in a finite number * of steps, it gets as close as possible * (a can be larger or smaller than b) * * @param step size of steps, must be positive * @param a first value of array * @param b last value of array * @throws IllegalArgumentException if step is * negative or if a=b. */ public static int[] range(int a, int b, int step) { if (step <= 0) { throw new IllegalArgumentException( "The argument step should be positive: " + step + " < 0"); } if (a == b) { int[] ans = new int[1]; ans[0] = a; return (ans); } int sizeOfArray = (new Double(Math.abs(a - b) / step)).intValue(); int[] ans = new int[sizeOfArray]; ans[0] = a; if (a > b) { step = -step; } for (int k = 1; k < sizeOfArray; k++) { ans[k] = ans[k - 1] + step; } return (ans); } /** * Takes the absolute value of each component of an array. */ public static double[] abs(double[] v) { double[] ans = new double[v.length]; for (int i = 0; i < v.length; i++) { ans[i] = Math.abs(v[i]); } return (ans); } /** * Takes the absolute value of each component of an array. */ public static double[][] abs(double[][] v) { double[][] ans = new double[v.length][]; for (int i = 0; i < v.length; i++) { ans[i] = abs(v[i]); } return (ans); } /** * Takes the absolute value of each component of an array. */ public static int[] abs(int[] v) { int[] ans = new int[v.length]; for (int i = 0; i < v.length; i++) { ans[i] = Math.abs(v[i]); } return (ans); } /** * Takes the absolute value of each component of an array. */ public static int[][] abs(int[][] v) { int[][] ans = new int[v.length][]; for (int i = 0; i < v.length; i++) { ans[i] = abs(v[i]); } return (ans); } }