001 /*
002 * $Id: BigDecimalTest.java 2194 2008-10-19 12:26:47Z kredel $
003 */
004
005 package edu.jas.arith;
006
007 import java.math.MathContext;
008
009 import junit.framework.Test;
010 import junit.framework.TestCase;
011 import junit.framework.TestSuite;
012
013 //import edu.jas.arith.BigDecimal;
014
015
016 /**
017 * BigDecimal tests with JUnit.
018 * @author Heinz Kredel.
019 */
020
021 public class BigDecimalTest extends TestCase {
022
023 /**
024 * main.
025 */
026 public static void main (String[] args) {
027 junit.textui.TestRunner.run( suite() );
028 }
029
030 /**
031 * Constructs a <CODE>BigDecimalTest</CODE> object.
032 * @param name String.
033 */
034 public BigDecimalTest(String name) {
035 super(name);
036 }
037
038 /**
039 */
040 public static Test suite() {
041 TestSuite suite= new TestSuite(BigDecimalTest.class);
042 return suite;
043 }
044
045 BigDecimal a;
046 BigDecimal b;
047 BigDecimal c;
048 BigDecimal d;
049 BigDecimal e;
050 BigDecimal fac;
051
052 int kl = 100;
053 int precision = 100; // must match default
054 MathContext mc = new MathContext( precision );
055
056 protected void setUp() {
057 a = b = c = d = e = null;
058 fac = new BigDecimal(0L,mc);
059 }
060
061 protected void tearDown() {
062 a = b = c = d = e = null;
063 fac = null;
064 }
065
066
067 /**
068 * Test static initialization and constants.
069 *
070 */
071 public void testConstants() {
072 a = BigDecimal.ZERO;
073 b = BigDecimal.ONE;
074 c = b.subtract(b);
075
076 assertTrue("1-1 = 0",c.compareTo(a)==0);
077 assertTrue("1-1 = 0",c.isZERO());
078 assertTrue("1 = 1", b.isONE() );
079
080 a = BigDecimal.ZERO;
081 b = BigDecimal.ONE;
082 c = b.subtract(b);
083
084 assertTrue("1-1 = 0",c.compareTo(a)==0);
085 }
086
087
088 /**
089 * Test constructor and toString.
090 *
091 */
092 public void testConstructor() {
093 a = new BigDecimal( "6.8" );
094 b = new BigDecimal( "3.4" );
095 b = b.sum(b);
096
097 assertEquals("6.8 = 3.4",0,a.compareTo(b));
098
099 String s = "6.1111111111111111111111111111111111111111111";
100 a = new BigDecimal( s );
101 String t = a.toString();
102
103 assertEquals("stringConstr = toString",s,t);
104
105 a = new BigDecimal( 1 );
106 b = new BigDecimal( -1 );
107 c = b.sum(a);
108
109 assertTrue("1 = 1", a.isONE() );
110 assertTrue("1+(-1) = 0", c.compareTo(BigDecimal.ZERO)==0 );
111 assertTrue("1+(-1) = 0", c.isZERO() );
112 }
113
114
115 /**
116 * Test random rationals.
117 *
118 */
119 public void testRandom() {
120 a = fac.random( 5*kl );
121 //System.out.println("a = " + a);
122 b = new BigDecimal( "" + a );
123 c = a.subtract(a);
124
125 //System.out.println("c = " + c);
126 //assertTrue("a-b = 0", c.compareTo(BigDecimal.ZERO)==0 );
127 assertTrue("a-b = 0", c.isZERO() );
128
129 d = new BigDecimal( "" + b );
130 //System.out.println("b = " + b);
131 //System.out.println("d = " + d);
132 assertTrue("sign(a-a) = 0", b.compareTo(d)==0 );
133 }
134
135
136 /**
137 * Test addition.
138 *
139 */
140 public void testAddition() {
141 a = fac.random( kl );
142 b = a.sum( a );
143 c = b.subtract( a );
144 //System.out.println("a = " + a);
145 //System.out.println("b = " + b);
146 //System.out.println("c = " + c);
147
148 //assertEquals("a+a-a = a", c, a);
149 assertEquals("a+a-a = a",0,c.compareTo(a));
150
151 d = a.sum( BigDecimal.ZERO );
152 assertEquals("a+0 = a",0,d.compareTo(a));
153 d = a.subtract( BigDecimal.ZERO );
154 assertEquals("a-0 = a",0,d.compareTo(a));
155 d = a.subtract( a );
156 assertTrue("a-a = 0", d.compareTo(BigDecimal.ZERO)==0);
157
158 b = fac.random( kl );
159 c = a.sum( b );
160 d = b.sum( a );
161 assertTrue("a-b = b+a", d.compareTo(c)==0 );
162
163 // addition is not associative
164 }
165
166
167 /**
168 * Test multiplication.
169 * Is not associative.
170 */
171 public void testMultiplication() {
172 a = fac.random( kl );
173 b = a.multiply( a );
174 c = b.divide( a );
175 //System.out.println("a = " + a);
176 //System.out.println("b = " + b);
177 //System.out.println("c = " + c);
178
179 //assertEquals("a*a/a = a",c,a);
180 assertTrue("a*a/a = a", c.compareTo(a)==0 );
181
182 d = a.multiply( BigDecimal.ONE );
183 assertEquals("a*1 = a",d,a);
184 d = a.divide( BigDecimal.ONE );
185 assertEquals("a/1 = a",0,d.compareTo(a));
186
187 a = fac.random( kl );
188 b = a.inverse();
189 c = a.multiply( b );
190 //System.out.println("c = " + c);
191 assertTrue("a*1/a = 1", c.compareTo( fac.getONE() ) == 0 );
192
193 b = fac.random( kl );
194 c = a.multiply( b );
195 d = b.multiply( a );
196 //System.out.println("c = " + c);
197 //System.out.println("d = " + d);
198 assertTrue("ab = ba",d.compareTo(c)==0);
199
200 c = fac.random( kl );
201 d = a.multiply( b.multiply( c ) );
202 e = a.multiply( b ).multiply( c );
203 //System.out.println("d = " + d);
204 //System.out.println("e = " + e);
205 if ( d.compareTo(e) == 0 ) {
206 assertTrue("a(bc) = (ab)c",d.compareTo(e)==0);
207 }
208 }
209
210
211 /**
212 * Test distributive law.
213 * Does not hold.
214 */
215 public void testDistributive() {
216 a = fac.random( kl );
217 b = fac.random( kl );
218 c = fac.random( kl );
219
220 d = a.multiply( b.sum( c ) );
221 e = a.multiply( b ).sum( a.multiply( c ) );
222 if ( d.compareTo(e) == 0 ) {
223 assertTrue("a(b+c) = ab+ac",d.compareTo(e)==0);
224 }
225 }
226
227 }