Markov chains in Java.
Installing
Maven:
<dependency>
<groupId>net.andreinc</groupId>
<artifactId>markovneat</artifactId>
<version>1.8</version>
</dependency>
Gradle:
implementation 'net.andreinc:markovneat:1.8'
You can also create a "fat" jar using the shadowJar
gradle tasks:
gradle shadowJar
The jar will be generated in /build/libs/markovneat*.jar
.
Example 1 - Modelling a simple discrete-time markov chain
A directed graph is used bellow to picture the state transitions for a Markov Chain.
The states represent whether a hypothetical stock market is exhibiting a bull market, bear market, or stagnant market trend during a given week.
(See Market trends).
With the markovneat library this can be modelled using the following code:
MChain<String> marketMChain = new MChain<>();
// Transitioning from "BULL" to "BULL" has a 90% chance
marketMChain.add(new MState<>("BULL"), "BULL", 0.9);
// Transitioning from "BULL" to "BEAR" has a 7,5% chance
marketMChain.add(new MState<>("BULL"), "BEAR", 0.075);
// Transitioning from "BULL" to "STAGNANT" has a 2,5% chance
marketMChain.add(new MState<>("BULL"), "STAGNANT", 0.025);
marketMChain.add(new MState<>("BEAR"), "BEAR", 0.8);
marketMChain.add(new MState<>("BEAR"), "BULL", 0.15);
marketMChain.add(new MState<>("BEAR"), "STAGNANT", 0.05);
marketMChain.add(new MState<>("STAGNANT"), "STAGNANT", 0.5);
marketMChain.add(new MState<>("STAGNANT"), "BULL", 0.25);
marketMChain.add(new MState<>("STAGNANT"), "BEAR", 0.25);
marketMChain.generate(10000).forEach(System.out::println);
Output:
STAGNANT
BULL
BULL
BULL
BULL
... and so on