com.Ostermiller.util Java Utilities

/*
 * Copyright (C) 2004-2007 Stephen Ostermiller
 * http://ostermiller.org/contact.pl?regarding=Java+Utilities
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * See COPYING.TXT for details.
 */
package com.Ostermiller.util;


/**
 * Significant Figures regression test.
 */
class SignificantFiguresTests {

	private static class TestCase {
		private String original;
		private int sigfigs;
		private String desiredResult;

		/**
		 * Test case
		 * @param original test number (as string)
		 * @param sigfigs number of significant figures to use
		 * @param desiredResult desired test result (number as string)
		 */
		public TestCase(String original, int sigfigs, String desiredResult){
			this.original = original;
			this.sigfigs = sigfigs;
			this.desiredResult = desiredResult;
		}
		private void test() throws Exception {
			String result = SignificantFigures.format(original, sigfigs);
			if (!desiredResult.equals(result)) throw new Exception("Got " + result + " but expected " + desiredResult + " for " + original + " with " + sigfigs + " significant digits.");
		}
	}
	private static final TestCase[] testCases = new TestCase[]{
		new TestCase("1234", 3, "1230"),
		new TestCase("60.91", 3, "60.9"),
		new TestCase("3343", 1, "3000"),
		new TestCase("200", 2, "2.0E2"), // not representable without scientific notation
		new TestCase("5097.808073851760832954355668151943215272", 3, "5.10E3"), // not representable without scientific notation
		new TestCase("6.15", 2, "6.2"), // rounding on a five - special even odd rule
		new TestCase("6.25", 2, "6.2"), // rounding on a five - special even odd rule
		new TestCase("6.150", 2, "6.2"), // rounding on a five - special even odd rule
		new TestCase("6.250", 2, "6.2"), // rounding on a five - special even odd rule
		new TestCase("6.1500", 2, "6.2"), // rounding on a five - special even odd rule
		new TestCase("6.2500", 2, "6.2"), // rounding on a five - special even odd rule
		new TestCase("6.153", 2, "6.2"), // when more digits special even odd rule does not apply when rounding on a five
		new TestCase("6.253", 2, "6.3"), // when more digits special even odd rule does not apply when rounding on a five
		new TestCase("200.123", 3, "200."), // decimal point at end
		new TestCase("234.123", 3, "234"), // no decimal point at end
		new TestCase("199.87", 3, "200."), // decimal point at end
		new TestCase(".0033234324", 2, "0.0033"), // gets leading zero
		new TestCase("0.0033234324", 2, "0.0033"), // keeps leading zero, can be represented without scientific notation
		new TestCase(".00033234324", 2, "3.3E-4"), // too small without scientific notation
		new TestCase("1234567", 3, "1230000"), // can be represented without scientific notation
		new TestCase("12345678", 3, "1.23E7"), // too large without scientific notation
	};

	/**
	 * Main method for regression test
	 * @param args command line arguments (ignored)
	 */
	public static void main(String[] args){
		try {
			for (int i=0; i<testCases.length; i++){
				testCases[i].test();
			}
		} catch (Exception x){
			x.printStackTrace(System.err);
			System.exit(1);
		}
		System.exit(0);
	}
}