Author: sebb
Date: Sat Feb 6 02:33:16 2010
New Revision: 907159
URL: http://svn.apache.org/viewvc?rev=907159&view=rev
Log:
Add some more test cases
Modified:
commons/proper/lang/branches/LANG_2_X/src/test/java/org/apache/commons/lang/math/RandomUtilsTest.java
Modified:
commons/proper/lang/branches/LANG_2_X/src/test/java/org/apache/commons/lang/math/RandomUtilsTest.java
URL:
http://svn.apache.org/viewvc/commons/proper/lang/branches/LANG_2_X/src/test/java/org/apache/commons/lang/math/RandomUtilsTest.java?rev=907159&r1=907158&r2=907159&view=diff
==============================================================================
---
commons/proper/lang/branches/LANG_2_X/src/test/java/org/apache/commons/lang/math/RandomUtilsTest.java
(original)
+++
commons/proper/lang/branches/LANG_2_X/src/test/java/org/apache/commons/lang/math/RandomUtilsTest.java
Sat Feb 6 02:33:16 2010
@@ -33,9 +33,6 @@
super(name);
}
- public void setUp() {
- }
-
/** test distribution of nextInt() */
public void testNextInt() {
tstNextInt(null);
@@ -97,6 +94,42 @@
chiSquare(expected,observed) < 16.27);
}
+ /**
+ * Generate 1000 values for nextInt(bound) and compare
+ * the observed frequency counts to expected counts using
+ * a chi-square test.
+ * @param bound upper bound to use
+ */
+ private void tstNextInt(int bound) {
+ assertTrue(bound+" Must be non-negative",bound>=0);
+ int result = 0;
+ Random rnd = new Random();
+ // test uniformity -- use Chi-Square test at .01 level
+ int[] expected = new int[] {500,500};
+ int[] observed = new int[] {0,0};
+ int[] observed2 = new int[] {0,0};
+ for (int i = 0; i < 1000; i ++) {
+ result = rnd.nextInt(bound);
+ assertTrue(result+" Must be non-negative",result>=0);
+ assertTrue(result+" Must be less than bound: "+bound,result<bound);
+ if (result < bound/2) {
+ observed[0]++;
+ } else {
+ observed[1]++;
+ }
+ observed2[result%2]++;
+ }
+ /* Use ChiSquare dist with df = 2-1 = 1, alpha = .001
+ * Change to 6.64 for alpha = .01
+ */
+ assertTrue(
+ "mid point chi-square test -- will fail about 1 in 1000 times ",
+ chiSquare(expected,observed) < 10.83);
+ assertTrue(
+ "odd/even chi-square test -- will fail about 1 in 1000 times",
+ chiSquare(expected,observed2) < 10.83);
+ }
+
/** test distribution of nextLong() */
public void testNextLong() {
tstNextLong(null);
@@ -112,7 +145,7 @@
}
/**
- * Generate 1000 values for nextLong and check that
+ * Generate 1000 values for nextLong() and check that
* p(value < long.MAXVALUE/2) ~ 0.5. Use chi-square test
* with df = 2-1 = 1
* @param rnd Random to use if not null
@@ -147,12 +180,57 @@
* Change to 6.64 for alpha = .01
*/
assertTrue(
- "chi-square test -- will fail about 1 in 1000 times",
+ "mid point chi-square test -- will fail about 1 in 1000 times",
chiSquare(expected,observed) < 10.83);
assertTrue(
- "chi-square test -- will fail about 1 in 1000 times",
+ "odd/even chi-square test -- will fail about 1 in 1000 times",
chiSquare(expected2,observed2) < 10.83);
}
+
+ /**
+ * Generate 1000 values for nextInt(bound) and compare
+ * the observed frequency counts to expected counts using
+ * a chi-square test.
+ * @param bound upper bound to use
+ */
+ private void tstNextLong(long bound) {
+ // Distribution
+ int[] expected = new int[] {500,500};
+ int[] observed = new int[] {0,0};
+ // Even/Odd
+ int[] expected2 = new int[] {500,500};
+ int[] observed2 = new int[] {0,0};
+ long result = 0;
+ long midPoint = bound/2;
+ for (int i = 0; i < 1000; i ++) {
+ result = JVMRandom.nextLong(bound);
+ assertTrue(result+" Must be non-negative",result>=0);
+ assertTrue(result+" Must be less than bound: "+bound,result<bound);
+ if (result < midPoint) {
+ observed[0]++;
+ } else {
+ observed[1]++;
+ }
+ if (result % 2 == 0) {
+ observed2[0]++;
+ } else {
+ observed2[1]++;
+ }
+ }
+ /* Use ChiSquare dist with df = 2-1 = 1, alpha = .001
+ * Change to 6.64 for alpha = .01
+ */
+ final double chiSquare = chiSquare(expected,observed);
+ assertTrue(
+ "mid point chi-square test -- will fail about 1 in 1000 times: "
+ +chiSquare+":"+observed[0]+","+observed[1],
+ chiSquare < 10.83);
+ final double oddEven = chiSquare(expected2,observed2);
+ assertTrue(
+ "odd/even chi-square test -- will fail about 1 in 1000 times: "
+ +oddEven+":"+observed2[0]+","+observed2[1],
+ oddEven < 10.83);
+ }
/** test distribution of nextBoolean() */
@@ -326,6 +404,40 @@
}
+ public void testNextIntBound(){
+ tstNextInt(10);
+ tstNextInt(1<<8);
+ tstNextInt((1<<8)+1);
+ tstNextInt((1<<8)-1);
+ tstNextInt(1<<30);
+ tstNextInt((1<<30)-1);
+ tstNextInt((1<<30)+1);
+ Random rnd = new Random();
+ for(int i=0;i<10;i++){
+ tstNextInt(rnd.nextInt(Integer.MAX_VALUE));
+ }
+ }
+
+ public void testNextLongBound(){
+ tstNextLong(Integer.MAX_VALUE-1);
+ tstNextLong(Integer.MAX_VALUE);
+ tstNextLong((long)Integer.MAX_VALUE+1);
+ tstNextLong(Long.MAX_VALUE/1024);
+ tstNextLong(Long.MAX_VALUE/920);
+ tstNextLong(Long.MAX_VALUE/1000);
+ tstNextLong(Long.MAX_VALUE/512);
+ tstNextLong(Long.MAX_VALUE/64);
+ tstNextLong(Long.MAX_VALUE-1);
+ tstNextLong(Long.MAX_VALUE);
+ Random rnd = new Random();
+ for(int i=0;i<10;i++){
+ tstNextLong(rnd.nextInt(Integer.MAX_VALUE));
+ }
+ for(int i=0;i<10;i++){
+ tstNextLong(rnd.nextLong() & 0x7fffffffffffffffL);
+ }
+ }
+
/**
* Computes Chi-Square statistic given observed and expected counts
* @param observed array of observed frequency counts
@@ -342,4 +454,3 @@
}
}
-
