1 package org.opentrafficsim.road.gtu.generator.headway;
2
3 import java.util.function.Supplier;
4
5 import org.djunits.value.vdouble.scalar.Duration;
6 import org.djunits.value.vdouble.scalar.Frequency;
7
8 import nl.tudelft.simulation.jstats.streams.StreamInterface;
9
10 /**
11 * Headway supplier using independent arrivals (exponential distribution) at a fixed average rate.
12 * <p>
13 * Copyright (c) 2013-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
14 * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
15 * </p>
16 * @author <a href="https://github.com/averbraeck">Alexander Verbraeck</a>
17 * @author <a href="https://github.com/peter-knoppers">Peter Knoppers</a>
18 * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
19 */
20 public class HeadwayGenerator implements Supplier<Duration>
21 {
22
23 /** Demand level. */
24 private final Frequency demand;
25
26 /** the stream information. */
27 private final StreamInterface stream;
28
29 /**
30 * Constructor.
31 * @param demand demand.
32 * @param stream the stream to use for generation.
33 */
34 public HeadwayGenerator(final Frequency demand, final StreamInterface stream)
35 {
36 this.demand = demand;
37 this.stream = stream;
38 }
39
40 @Override
41 public Duration get()
42 {
43 return Duration.ofSI(-Math.log(this.stream.nextDouble()) / this.demand.si);
44 }
45
46 }