iSharkFly-Docs
/
java-tutorials
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Merge pull request #9758 from mdabrowski-eu/BAEL-4405-probability 

BAEL-4405 Probability in Java
This commit is contained in:
davidmartinezbarua 2020-08-08 15:08:41 -03:00 committed by GitHub
parent dae31cd19e 1b2f33e4d4
commit 11ad6d048b
5 changed files with 129 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
java-numbers-4/pom.xml Normal file
View File

@ -0,0 +1,52 @@
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<artifactId>java-numbers-4</artifactId>
<name>java-numbers-4</name>
<packaging>jar</packaging>
<parent>
<groupId>com.baeldung</groupId>
<artifactId>parent-java</artifactId>
<version>0.0.1-SNAPSHOT</version>
<relativePath>../parent-java</relativePath>
</parent>
<dependencies>
<dependency>
<groupId>io.vavr</groupId>
<artifactId>vavr</artifactId>
<version>${vavr.version}</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-lang3</artifactId>
<version>${commons.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.assertj</groupId>
<artifactId>assertj-core</artifactId>
<version>${assertj.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<finalName>java-numbers-4</finalName>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
<properties>
<vavr.version>0.10.2</vavr.version>
<commons.version>3.9</commons.version>
<assertj.version>3.6.1</assertj.version>
</properties>
</project>

17
java-numbers-4/src/main/java/com/baeldung/probability/MaleHeightGenerator.java Normal file
View File

@ -0,0 +1,17 @@
package com.baeldung.probability;
import org.apache.commons.math3.distribution.NormalDistribution;
public class MaleHeightGenerator {
private static final double MEAN_HEIGHT = 176.02;
private static final double STANDARD_DEVIATION = 7.11;
private static NormalDistribution distribution = new NormalDistribution(MEAN_HEIGHT, STANDARD_DEVIATION);
public static double generateNormalHeight() {
return distribution.sample();
}
public static double probabilityOfHeightBetween(double heightLowerExclusive, double heightUpperInclusive) {
return distribution.probability(heightLowerExclusive, heightUpperInclusive);
}
}

19
java-numbers-4/src/main/java/com/baeldung/probability/RandomInvoker.java Normal file
View File

@ -0,0 +1,19 @@
package com.baeldung.probability;
import io.vavr.Lazy;
import java.util.SplittableRandom;
import java.util.function.Supplier;
public class RandomInvoker {
private final Lazy<SplittableRandom> random = Lazy.of(SplittableRandom::new);
public <T> T withProbability(Supplier<T> positiveCase, Supplier<T> negativeCase, int probability) {
SplittableRandom random = this.random.get();
if (random.nextInt(1, 101) <= probability) {
return positiveCase.get();
} else {
return negativeCase.get();
}
}
}

24
java-numbers-4/src/test/java/com/baeldung/probability/RandomInvokerUnitTest.java Normal file
View File

@ -0,0 +1,24 @@
package com.baeldung.probability;
import org.assertj.core.data.Offset;
import org.junit.Test;
import java.util.stream.Stream;
import static org.assertj.core.api.Assertions.assertThat;
public class RandomInvokerUnitTest {
@Test
public void givenProbability_whenInvoked_invokeWithProbability() {
RandomInvoker randomInvoker = new RandomInvoker();
int numberOfSamples = 1_000_000;
int probability = 10;
int howManyTimesInvoked = Stream.generate(() -> randomInvoker.withProbability(() -> 1, () -> 0, probability))
.limit(numberOfSamples)
.mapToInt(e -> e).sum();
int monteCarloProbability = (howManyTimesInvoked * 100) / numberOfSamples;
assertThat(monteCarloProbability).isCloseTo(probability, Offset.offset(1));
}
}

32
pom.xml
View File

@ -343,18 +343,18 @@
<module>animal-sniffer-mvn-plugin</module>
<module>annotations</module>
<module>antlr</module>
<module>apache-cxf</module>
<module>apache-libraries</module>
<module>apache-olingo/olingo2</module>
<module>apache-poi</module>
<module>apache-cxf</module>
<module>apache-libraries</module>
<module>apache-olingo/olingo2</module>
<module>apache-poi</module>
<module>apache-rocketmq</module>
<module>apache-shiro</module>
<module>apache-shiro</module>
<module>apache-spark</module>
<module>apache-tapestry</module>
<module>apache-thrift</module>
<module>apache-tika</module>
<module>apache-velocity</module>
<module>apache-velocity</module>
<module>asciidoctor</module>
<module>asm</module>
@ -443,7 +443,8 @@
<module>java-lite</module>
<module>java-numbers</module>
<module>java-numbers-2</module>
<module>java-numbers-3</module>
<module>java-numbers-3</module>
<module>java-numbers-4</module>
<module>java-rmi</module>
<module>java-spi</module>
<module>java-vavr-stream</module>
@ -856,18 +857,18 @@
<module>animal-sniffer-mvn-plugin</module>
<module>annotations</module>
<module>antlr</module>
<module>apache-cxf</module>
<module>apache-libraries</module>
<module>apache-olingo/olingo2</module>
<module>apache-poi</module>
<module>apache-cxf</module>
<module>apache-libraries</module>
<module>apache-olingo/olingo2</module>
<module>apache-poi</module>
<module>apache-rocketmq</module>
<module>apache-shiro</module>
<module>apache-shiro</module>
<module>apache-spark</module>
<module>apache-tapestry</module>
<module>apache-thrift</module>
<module>apache-tika</module>
<module>apache-velocity</module>
<module>apache-velocity</module>
<module>asciidoctor</module>
<module>asm</module>
@ -956,6 +957,7 @@
<module>java-numbers</module>
<module>java-numbers-2</module>
<module>java-numbers-3</module>
<module>java-numbers-4</module>
<module>java-rmi</module>
<module>java-spi</module>
<module>java-vavr-stream</module>