TransitionProbabilityFunction.java

package aima.core.probability.mdp;

import aima.core.agent.Action;

/**
 * An interface for MDP transition probability functions.
 * 
 * @param <S>
 *            the state type.
 * @param <A>
 *            the action type.
 * 
 * @author Ciaran O'Reilly
 * @author Ravi Mohan
 */
public interface TransitionProbabilityFunction<S, A extends Action> {

	/**
	 * Return the probability of going from state s using action a to s' based
	 * on the underlying transition model P(s' | s, a).
	 * 
	 * @param sDelta
	 *            the state s' being transitioned to.
	 * @param s
	 *            the state s being transitions from.
	 * @param a
	 *            the action used to move from state s to s'.
	 * @return the probability of going from state s using action a to s'.
	 */
	double probability(S sDelta, S s, A a);
}