Showing elevation along a path

View this example full screen.

JavaScript

var elevator;
var map;
var chart;
var polyline;

// The following path marks a general path from Mt.
// Whitney, the highest point in the continental United
// States to Badwater, Death Valley, the lowest point.
var whitney = new google.maps.LatLng(36.578581, -118.291994);
var lonepine = new google.maps.LatLng(36.606111, -118.062778);
var owenslake = new google.maps.LatLng(36.433269, -117.950916);
var beattyjunction = new google.maps.LatLng(36.588056, -116.943056);
var panamintsprings = new google.maps.LatLng(36.339722, -117.467778);
var badwater = new google.maps.LatLng(36.23998, -116.83171);

// Load the Visualization API and the columnchart package.
google.load('visualization', '1', {packages: ['columnchart']});

function initialize() {
  var mapOptions = {
    zoom: 8,
    center: lonepine,
    mapTypeId: 'terrain'
  }
  map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);

  // Create an ElevationService.
  elevator = new google.maps.ElevationService();

  // Draw the path, using the Visualization API and the Elevation service.
  drawPath();
}

function drawPath() {

  // Create a new chart in the elevation_chart DIV.
  chart = new google.visualization.ColumnChart(document.getElementById('elevation_chart'));

  var path = [ whitney, lonepine, owenslake, panamintsprings, beattyjunction, badwater];

  // Create a PathElevationRequest object using this array.
  // Ask for 256 samples along that path.
  var pathRequest = {
    'path': path,
    'samples': 256
  }

  // Initiate the path request.
  elevator.getElevationAlongPath(pathRequest, plotElevation);
}

// Takes an array of ElevationResult objects, draws the path on the map
// and plots the elevation profile on a Visualization API ColumnChart.
function plotElevation(results, status) {
  if (status != google.maps.ElevationStatus.OK) {
    return;
  }
  var elevations = results;

  // Extract the elevation samples from the returned results
  // and store them in an array of LatLngs.
  var elevationPath = [];
  for (var i = 0; i < results.length; i++) {
    elevationPath.push(elevations[i].location);
  }

  // Display a polyline of the elevation path.
  var pathOptions = {
    path: elevationPath,
    strokeColor: '#0000CC',
    opacity: 0.4,
    map: map
  }
  polyline = new google.maps.Polyline(pathOptions);

  // Extract the data from which to populate the chart.
  // Because the samples are equidistant, the 'Sample'
  // column here does double duty as distance along the
  // X axis.
  var data = new google.visualization.DataTable();
  data.addColumn('string', 'Sample');
  data.addColumn('number', 'Elevation');
  for (var i = 0; i < results.length; i++) {
    data.addRow(['', elevations[i].elevation]);
  }

  // Draw the chart using the data within its DIV.
  document.getElementById('elevation_chart').style.display = 'block';
  chart.draw(data, {
    height: 150,
    legend: 'none',
    titleY: 'Elevation (m)'
  });
}

google.maps.event.addDomListener(window, 'load', initialize);

JavaScript + HTML

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="initial-scale=1.0, user-scalable=no">
    <meta charset="utf-8">
    <title>Showing elevation along a path</title>
    <style>
      html, body, #map-canvas {
        height: 100%;
        margin: 0px;
        padding: 0px
      }
    </style>
    <script src="https://www.google.com/jsapi"></script>
    <script src="https://maps.googleapis.com/maps/api/js?v=3.exp&signed_in=true"></script>
    <script>
var elevator;
var map;
var chart;
var polyline;

// The following path marks a general path from Mt.
// Whitney, the highest point in the continental United
// States to Badwater, Death Valley, the lowest point.
var whitney = new google.maps.LatLng(36.578581, -118.291994);
var lonepine = new google.maps.LatLng(36.606111, -118.062778);
var owenslake = new google.maps.LatLng(36.433269, -117.950916);
var beattyjunction = new google.maps.LatLng(36.588056, -116.943056);
var panamintsprings = new google.maps.LatLng(36.339722, -117.467778);
var badwater = new google.maps.LatLng(36.23998, -116.83171);

// Load the Visualization API and the columnchart package.
google.load('visualization', '1', {packages: ['columnchart']});

function initialize() {
  var mapOptions = {
    zoom: 8,
    center: lonepine,
    mapTypeId: 'terrain'
  }
  map = new google.maps.Map(document.getElementById('map-canvas'), mapOptions);

  // Create an ElevationService.
  elevator = new google.maps.ElevationService();

  // Draw the path, using the Visualization API and the Elevation service.
  drawPath();
}

function drawPath() {

  // Create a new chart in the elevation_chart DIV.
  chart = new google.visualization.ColumnChart(document.getElementById('elevation_chart'));

  var path = [ whitney, lonepine, owenslake, panamintsprings, beattyjunction, badwater];

  // Create a PathElevationRequest object using this array.
  // Ask for 256 samples along that path.
  var pathRequest = {
    'path': path,
    'samples': 256
  }

  // Initiate the path request.
  elevator.getElevationAlongPath(pathRequest, plotElevation);
}

// Takes an array of ElevationResult objects, draws the path on the map
// and plots the elevation profile on a Visualization API ColumnChart.
function plotElevation(results, status) {
  if (status != google.maps.ElevationStatus.OK) {
    return;
  }
  var elevations = results;

  // Extract the elevation samples from the returned results
  // and store them in an array of LatLngs.
  var elevationPath = [];
  for (var i = 0; i < results.length; i++) {
    elevationPath.push(elevations[i].location);
  }

  // Display a polyline of the elevation path.
  var pathOptions = {
    path: elevationPath,
    strokeColor: '#0000CC',
    opacity: 0.4,
    map: map
  }
  polyline = new google.maps.Polyline(pathOptions);

  // Extract the data from which to populate the chart.
  // Because the samples are equidistant, the 'Sample'
  // column here does double duty as distance along the
  // X axis.
  var data = new google.visualization.DataTable();
  data.addColumn('string', 'Sample');
  data.addColumn('number', 'Elevation');
  for (var i = 0; i < results.length; i++) {
    data.addRow(['', elevations[i].elevation]);
  }

  // Draw the chart using the data within its DIV.
  document.getElementById('elevation_chart').style.display = 'block';
  chart.draw(data, {
    height: 150,
    legend: 'none',
    titleY: 'Elevation (m)'
  });
}

google.maps.event.addDomListener(window, 'load', initialize);

    </script>
  </head>
  <body>
    <div>
      <div id="map-canvas" style="height:250px;"></div>
      <div id="elevation_chart"></div>
    </div>
  </body>
</html>

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Last updated March 17, 2015.