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1 package JSci.tests;
2
3 import java.util.Random  ;
4 import JSci.maths.*;
5
6
10 public class ArrayTest extends junit.framework.TestCase {
11 private final Random random = new Random ();
12
13 public static void main(String arg[]) {
14 junit.textui.TestRunner.run(ArrayTest.class);
15 }
16 public ArrayTest(String name) {
17 super(name);
18 }
19 protected void setUp() {
20 JSci.GlobalSettings.ZERO_TOL=1.0e-6;
21 }
22 public void testMedian() {
23 final int N = random.nextInt(31)+1;
24 double array[] = new double[N];
25 array[0] = random.nextDouble();
26 for(int i=1; i<N; i++) {
27 array[i] = random.nextDouble();
28 if(array[i] < array[i-1])
29 array[i]+=array[i-1];
30 }
31 double expected;
32 if(isEven(N))
33 expected = (array[N/2-1]+array[N/2])/2.0;
34 else
35 expected = array[N/2];
36 randomize(array);
37 double ans = ArrayMath.median(array);
38 assertEquals("["+ArrayMath.toString(array)+"]", expected, ans, 0.0);
39 }
40 private static boolean isEven(int n) {
41 return (n % 2 == 0);
42 }
43 private void randomize(double array[]) {
44 for(int i=0; i<array.length; i++) {
45 int p = random.nextInt(array.length);
46 int q = random.nextInt(array.length);
47 double tmp = array[q];
48 array[q] = array[p];
49 array[p] = tmp;
50 }
51 }
52 }
53
54 |
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