GPX fake timer

Create timestamps for every trackpoint in a GPX file.

yarn add @mikaello/gpxfaketimer

Example

import { createTimestampsEvenly } from "@mikaello/gpxfaketimer";

const exampleGpx = `
<?xml version="1.0" encoding="UTF-8"?>
<gpx xmlns="http://www.topografix.com/GPX/1/1" version="1.0">
  <name>Example gpx</name>
  <trk>
    <name>Example gpx</name>
    <number>1</number>
    <trkseg>
      <trkpt lat="46.57608333" lon="8.89241667">
        <ele>2376</ele>
      </trkpt>
      <trkpt lat="46.57619444" lon="8.89252778">
        <ele>2375</ele>
      </trkpt>
      <trkpt lat="46.57661111" lon="8.89344444">
        <ele>2376</ele>
      </trkpt>
    </trkseg>
  </trk>
</gpx>
`;

console.log(createTimestampsEvenly(exampleGpx, 0, 100000));
// => will return the same GPX file, only with <time>date here</time> inside every trkpt:

/*
<?xml version="1.0" encoding="UTF-8"?>
<gpx xmlns="http://www.topografix.com/GPX/1/1" version="1.0">
  <name>Example gpx</name>
  <trk>
    <name>Example gpx</name>
    <number>1</number>
    <trkseg>
      <trkpt lat="46.57608333" lon="8.89241667">
        <ele>2376</ele>
        <time>1970-01-01T00:00:00.000Z</time>
      </trkpt>
      <trkpt lat="46.57619444" lon="8.89252778">
        <ele>2375</ele>
        <time>1970-01-01T00:00:50.000Z</time>
      </trkpt>
      <trkpt lat="46.57661111" lon="8.89344444">
        <ele>2376</ele>
        <time>1970-01-01T00:01:40.000Z</time>
      </trkpt>
    </trkseg>
  </trk>
</gpx>
*/

API

• createTimestampsEvenly(gpxContent: string, startTime: number, endTime: number) => string:
  returns the incoming gpxContent enriched with timestamps in every trkpt
  element. startTime and endTime are milliseconds since epoch.

Utility functions

Not specific for GPX, but just as helper functions

getUniformDistribution(count: number, intervalStart: number, intervalEnd: number) => number[]: returns an array of length count with first element intervalStart and last element intervalEnd, all elements in between is evenly distributed between these extremeties.

Develop

You can use the ./example project to ease developing. If you run yarn start from that folder, you will start a server running a small application which loads the code from this module. Run yarn dev in another terminal to start to continously watch the code and recompile (and reload server) when any code changes.

Contributions are welcome :-)