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