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MersenneTwisterFast: clean up a bit, remove main
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Lines changed: 8 additions & 179 deletions

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‎scijava-common3/src/main/java/org/scijava/common3/MersenneTwisterFast.java‎

Lines changed: 8 additions & 179 deletions
Original file line numberDiff line numberDiff line change
@@ -33,10 +33,12 @@
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import java.io.DataOutputStream;
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import java.io.IOException;
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import java.io.Serializable;
36-
import java.util.Random;
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/**
39-
* <h2>MersenneTwister and MersenneTwisterFast</h2>
38+
* A faster version of {@link java.util.Random} functionality,
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* built on the Mersenne Twister algorithm.
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*
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* <h3>MersenneTwister and MersenneTwisterFast</h3>
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* <p>
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* <b>Version 17</b>, based on version MT199937(99/10/29) of the Mersenne
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* Twister algorithm found at
@@ -148,7 +150,9 @@
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* MersenneTwister can be used reliably on JDK version 1.1.5 or above. Earlier
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* Java versions have serious bugs in java.util.Random; only MersenneTwisterFast
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* (and not MersenneTwister nor java.util.Random) should be used with them.
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* <h3>License</h3> Copyright (c) 2003 by Sean Luke. <br>
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*
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* <h3>License</h3>
155+
* Copyright (c) 2003 by Sean Luke. <br>
152156
* Portions copyright (c) 1993 by Michael Lecuyer. <br>
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* All rights reserved. <br>
154158
* <p>
@@ -191,10 +195,7 @@ public strictfp class MersenneTwisterFast implements Serializable, Cloneable {
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// -- Sean
192196

193197
// Serialization
194-
private static final long serialVersionUID = -8219700664442619525L; // locked
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// as of
196-
// Version
197-
// 15
198+
private static final long serialVersionUID = -8219700664442619525L; // locked as of Version 15
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199200
// Period parameters
200201
private static final int N = 624;
@@ -1205,176 +1206,4 @@ public final int nextInt(final int n) {
12051206
while (bits - val + (n - 1) < 0);
12061207
return val;
12071208
}
1208-
1209-
/**
1210-
* Tests the code.
1211-
*/
1212-
public static void main(String args[]) {
1213-
int j;
1214-
1215-
MersenneTwisterFast r;
1216-
1217-
// CORRECTNESS TEST
1218-
// COMPARE WITH
1219-
// http://www.math.keio.ac.jp/matumoto/CODES/MT2002/mt19937ar.out
1220-
1221-
r = new MersenneTwisterFast(new int[] { 0x123, 0x234, 0x345, 0x456 });
1222-
System.out.println(
1223-
"Output of MersenneTwisterFast with new (2002/1/26) seeding mechanism");
1224-
for (j = 0; j < 1000; j++) {
1225-
// first, convert the int from signed to "unsigned"
1226-
long l = (long) r.nextInt();
1227-
if (l < 0) l += 4294967296L; // max int value
1228-
String s = String.valueOf(l);
1229-
while (s.length() < 10)
1230-
s = " " + s; // buffer
1231-
System.out.print(s + " ");
1232-
if (j % 5 == 4) System.out.println();
1233-
}
1234-
1235-
// SPEED TEST
1236-
1237-
final long SEED = 4357;
1238-
1239-
int xx;
1240-
long ms;
1241-
System.out.println("\nTime to test grabbing 100000000 ints");
1242-
1243-
Random rr = new Random(SEED);
1244-
xx = 0;
1245-
ms = System.currentTimeMillis();
1246-
for (j = 0; j < 100000000; j++)
1247-
xx += rr.nextInt();
1248-
System.out.println("java.util.Random: " + (System.currentTimeMillis() -
1249-
ms) + " Ignore this: " + xx);
1250-
1251-
r = new MersenneTwisterFast(SEED);
1252-
ms = System.currentTimeMillis();
1253-
xx = 0;
1254-
for (j = 0; j < 100000000; j++)
1255-
xx += r.nextInt();
1256-
System.out.println("Mersenne Twister Fast: " + (System.currentTimeMillis() -
1257-
ms) + " Ignore this: " + xx);
1258-
1259-
// TEST TO COMPARE TYPE CONVERSION BETWEEN
1260-
// MersenneTwisterFast.java AND MersenneTwister.java
1261-
1262-
System.out.println("\nGrab the first 1000 booleans");
1263-
r = new MersenneTwisterFast(SEED);
1264-
for (j = 0; j < 1000; j++) {
1265-
System.out.print(r.nextBoolean() + " ");
1266-
if (j % 8 == 7) System.out.println();
1267-
}
1268-
if (!(j % 8 == 7)) System.out.println();
1269-
1270-
System.out.println(
1271-
"\nGrab 1000 booleans of increasing probability using nextBoolean(double)");
1272-
r = new MersenneTwisterFast(SEED);
1273-
for (j = 0; j < 1000; j++) {
1274-
System.out.print(r.nextBoolean((double) (j / 999.0)) + " ");
1275-
if (j % 8 == 7) System.out.println();
1276-
}
1277-
if (!(j % 8 == 7)) System.out.println();
1278-
1279-
System.out.println(
1280-
"\nGrab 1000 booleans of increasing probability using nextBoolean(float)");
1281-
r = new MersenneTwisterFast(SEED);
1282-
for (j = 0; j < 1000; j++) {
1283-
System.out.print(r.nextBoolean((float) (j / 999.0f)) + " ");
1284-
if (j % 8 == 7) System.out.println();
1285-
}
1286-
if (!(j % 8 == 7)) System.out.println();
1287-
1288-
byte[] bytes = new byte[1000];
1289-
System.out.println("\nGrab the first 1000 bytes using nextBytes");
1290-
r = new MersenneTwisterFast(SEED);
1291-
r.nextBytes(bytes);
1292-
for (j = 0; j < 1000; j++) {
1293-
System.out.print(bytes[j] + " ");
1294-
if (j % 16 == 15) System.out.println();
1295-
}
1296-
if (!(j % 16 == 15)) System.out.println();
1297-
1298-
byte b;
1299-
System.out.println(
1300-
"\nGrab the first 1000 bytes -- must be same as nextBytes");
1301-
r = new MersenneTwisterFast(SEED);
1302-
for (j = 0; j < 1000; j++) {
1303-
System.out.print((b = r.nextByte()) + " ");
1304-
if (b != bytes[j]) System.out.print("BAD ");
1305-
if (j % 16 == 15) System.out.println();
1306-
}
1307-
if (!(j % 16 == 15)) System.out.println();
1308-
1309-
System.out.println("\nGrab the first 1000 shorts");
1310-
r = new MersenneTwisterFast(SEED);
1311-
for (j = 0; j < 1000; j++) {
1312-
System.out.print(r.nextShort() + " ");
1313-
if (j % 8 == 7) System.out.println();
1314-
}
1315-
if (!(j % 8 == 7)) System.out.println();
1316-
1317-
System.out.println("\nGrab the first 1000 ints");
1318-
r = new MersenneTwisterFast(SEED);
1319-
for (j = 0; j < 1000; j++) {
1320-
System.out.print(r.nextInt() + " ");
1321-
if (j % 4 == 3) System.out.println();
1322-
}
1323-
if (!(j % 4 == 3)) System.out.println();
1324-
1325-
System.out.println("\nGrab the first 1000 ints of different sizes");
1326-
r = new MersenneTwisterFast(SEED);
1327-
int max = 1;
1328-
for (j = 0; j < 1000; j++) {
1329-
System.out.print(r.nextInt(max) + " ");
1330-
max *= 2;
1331-
if (max <= 0) max = 1;
1332-
if (j % 4 == 3) System.out.println();
1333-
}
1334-
if (!(j % 4 == 3)) System.out.println();
1335-
1336-
System.out.println("\nGrab the first 1000 longs");
1337-
r = new MersenneTwisterFast(SEED);
1338-
for (j = 0; j < 1000; j++) {
1339-
System.out.print(r.nextLong() + " ");
1340-
if (j % 3 == 2) System.out.println();
1341-
}
1342-
if (!(j % 3 == 2)) System.out.println();
1343-
1344-
System.out.println("\nGrab the first 1000 longs of different sizes");
1345-
r = new MersenneTwisterFast(SEED);
1346-
long max2 = 1;
1347-
for (j = 0; j < 1000; j++) {
1348-
System.out.print(r.nextLong(max2) + " ");
1349-
max2 *= 2;
1350-
if (max2 <= 0) max2 = 1;
1351-
if (j % 4 == 3) System.out.println();
1352-
}
1353-
if (!(j % 4 == 3)) System.out.println();
1354-
1355-
System.out.println("\nGrab the first 1000 floats");
1356-
r = new MersenneTwisterFast(SEED);
1357-
for (j = 0; j < 1000; j++) {
1358-
System.out.print(r.nextFloat() + " ");
1359-
if (j % 4 == 3) System.out.println();
1360-
}
1361-
if (!(j % 4 == 3)) System.out.println();
1362-
1363-
System.out.println("\nGrab the first 1000 doubles");
1364-
r = new MersenneTwisterFast(SEED);
1365-
for (j = 0; j < 1000; j++) {
1366-
System.out.print(r.nextDouble() + " ");
1367-
if (j % 3 == 2) System.out.println();
1368-
}
1369-
if (!(j % 3 == 2)) System.out.println();
1370-
1371-
System.out.println("\nGrab the first 1000 gaussian doubles");
1372-
r = new MersenneTwisterFast(SEED);
1373-
for (j = 0; j < 1000; j++) {
1374-
System.out.print(r.nextGaussian() + " ");
1375-
if (j % 3 == 2) System.out.println();
1376-
}
1377-
if (!(j % 3 == 2)) System.out.println();
1378-
1379-
}
13801209
}

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