google maps api - heatmap.set(data) property - google-maps

Question

I am creating a simple google map with heatmap layer. Importantly, I am not setting the data property of the heatmap initially:
var map, heatmap;
var home = new google.maps.LatLng(37.75, -122.4)
function initialize() {
var mapOptions = {
zoom: 10,
minZoom: 3,
center: home,
mapTypeId: google.maps.MapTypeId.ROADMAP,
disableDefaultUI: true,
panControl: false,
zoomControl: true,
mapTypeControl: false,
scaleControl: false,
streetViewControl: false,
overviewMapControl: false
};
var styles = [
{
stylers: [
{ "gamma": 0.83 },
{ hue: "#00ffe6" },
{ saturation: -20 }
]
},{
featureType: "road",
elementType: "geometry",
stylers: [
{ lightness: 100 },
{ visibility: "simplified" }
]
},{
featureType: "road",
elementType: "labels",
stylers: [
{ visibility: "off" }
]
}
];
map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
map.setOptions({styles: styles});
heatmap = new google.maps.visualization.HeatmapLayer({
radius: 20,
opacity: 0.5
});
heatmap.setMap(map);
then I create a function which should set the data property of the heatmap, like this:
function update(){
all = [[37.782551, -122.445368, 0.75, 0.25],
[37.782745, -122.444586, 0.5, 0.5],
[37.782842, -122.443688, 0.2, 0.8]]
temp = []
for (var i = 0; i < all.length; i++){
temp.push(new google.maps.LatLng(all[i][0], all[i][1]), all[i][2])
}
var newdata = new google.maps.MVCArray(temp);
heatmap.set('data', heatmap.get('data') ? null : newdata)
}
finally, i call the update function in a bounds_changed event and initialize the map:
google.maps.event.addListener(map, 'bounds_changed', function() {
update;
});
}
google.maps.event.addDomListener(window, 'load', initialize);
However, when I inspect the heatmap variable in the console, the data property is null. Why is this? and how do I set the data property in a function call?

Answer 1

calling heatmap.set('data', heatmap.get('data') ? null : newdata); is problematic.
Remove that and it works.
working fiddle