Rails google maps api：InvalidValueError：setMap：不是Map

Question

我使用rails 4.2，我尝试根据我的数据显示热图。我只能显示地图，因为热图会给我InvalidValueError: setMap: not an instance of Map这个错误。因此热图不起作用，只能看到默认地图。 我的javascript代码如下所示

:javascript
  var map;
  function initialize() {
     var mapOptions = {
        zoom: 10,
        center: {lat: latitude, lng: longitude},
        mapTypeId: 'satellite'
     };
     map = new google.maps.Map(document.getElementById("map"),
         mapOptions);
   };

  $( document ).ready(function() {
     initialize();
     function initMap() {
        var adrs = #{addresses.map{ |address| address[:address_set].select{ |a| a.latitude.present? && a.longitude.present? }.map{ |a| [a.latitude, a.longitude] }.uniq}};
        var gradients = [
      [
      'rgba(255, 0, 255, 0)',
      'rgba(255, 0, 255, 1)',
      'rgba(225, 0, 245, 1)',
      'rgba(205, 0, 235, 1)',
      'rgba(185, 0, 225, 1)',
      'rgba(165, 0, 215, 1)',
      'rgba(145, 0, 205, 1)',
      'rgba(125, 0, 195, 1)',
      'rgba(105, 0, 185, 1)',
      'rgba(85, 0, 175, 1)',
      'rgba(65, 0, 165, 1)',
      'rgba(45, 0, 155, 1)',
      'rgba(25, 0, 145, 1)',
      'rgba(0, 0, 135, 1)'
      ]
    ];

  function getPoints(points) {
    var gcs = [];
    points.forEach(function(value) {
      gcs.push(new google.maps.LatLng(value[0], value[1]));
    });
    return gcs;
  };

  heatmaps = [];
  for(var i = 0; i < adrs.length; i++) {
    heatmaps[i] = new google.maps.visualization.HeatmapLayer({
      data: getPoints(adrs[i]),
      gradient: gradients[i],
      radius: 10,
      opacity: 0.5,
      maxIntensity: 8,
      map: map
    });
  };
}
function toggleHeatmap() {
  for(var i = 0; i < heatmaps.length; i++) {
    heatmaps[i].setMap(map);
  };
}

 initMap();
 $('.change').on('click',function(e){
   e.preventDefault();
   toggleHeatmap();
  });
});

所有数据都运行良好，但仍然显示错误。我该如何解决？ 提前谢谢！