Google Map Chart Marker Clusterer - javascript

I'm trying to add Marker Clustering to my Google Map chart with no success. I have a function which puts markers on the map based on lat/long. My understanding Map chart will not display more than 400 or so markers, which i don't really want anyway but i'd rather have clustering in place. This way my user sees, for example, single marker for Los Angeles and San Francisco, which would be broken down into multiple when zoom in.
I've looked into https://developers.google.com/maps/documentation/javascript/marker-clustering
but still can't connect dots and implement it into my function
function drawMapChart() {
var array_map = []
var header_map=[]
header_map.push('latitude')
header_map.push('longitude')
header_map.push('name')
array_map.push(header_map)
array_map.push([{v:34.043736},{v:-118.464298},{v:"city A"}])
array_map.push([{v:34.043003},{v:-118.448385},{v:"city B"}])
var data = google.visualization.arrayToDataTable(array_map);
var chart = new google.visualization.ChartWrapper({
chartType:'Map',
containerId:'map_chart_div',
options:{
mapType: 'normal'
},
dataTable:data
});
chart.draw();
}
Help is much appreciated!

It looks like the problem was that my implementation was through map chart (google charts), which from my understanding uses google maps api so i thought it should work. However, i couldn't find the way on how to add MarkerClusterer to that and so as a solution i just rebuilt the page using google maps api (following the example in the link) skipping google chart altogether.

Related

I have a location list of 300000 elements and want to visualize them on my localhost

Basically, what I have is a geolocation data (longtitude and latitudes) of 300.000 locations. I have different attributes attached to the data and it is approx. 32MB. Reading it through js and putting markers on google maps is what I've tried, and It works OK when i put only 25 to 2500 markers on my map, I cant really put all of my locations at once. Eventually I want to be able to filter markers through the attributes etc. The locations are all at one city, so I might use my own map or something.
What I want to ask/learn is do you have any better solutions for this particular situation?
Here is my code.
function initJS() {
var promise = getData();
var locations1;
var locations;
promise.success( (data) => {
locations1 = parseData(data);
locations = locations1.filter(location => {
return location.DuyuruTipi == "16";
});
//initializing google map
map = new google.maps.Map(document.getElementById("map"), {
center: { lat: latitude, lng:longtitude},
zoom: zooming,
});
//creating a marker
const svgMarker = {
// path: "M10.453 14.016l6.563-6.609-1.406-1.406-5.156 5.203-2.063-2.109-1.406 1.406zM12 2.016q2.906 0 4.945 2.039t2.039 4.945q0 1.453-0.727 3.328t-1.758 3.516-2.039 3.070-1.711 2.273l-0.75 0.797q-0.281-0.328-0.75-0.867t-1.688-2.156-2.133-3.141-1.664-3.445-0.75-3.375q0-2.906 2.039-4.945t4.945-2.039z",
url: "./assets/marker.svg",
size: new google.maps.Size(20,20),
scaledSize: new google.maps.Size(20,20),
origin: new google.maps.Point(0, 0),
anchor: new google.maps.Point(10, 10),
};
for (var i = 0; i < locations.length; i++) { //locations.length
// init markers
var marker = new google.maps.Marker({
position: { lat: parseFloat(locations[i]["YCoor"]), lng: parseFloat(locations[i]["XCoor"])},
map: map,
label: locations[i]["DuyuruId"],
icon: svgMarker
});
console.log(locations[i]["DuyuruTipi"]);
marker.duyurutipi = locations[i]["DuyuruTipi"];
marker.kazatipi = locations[i]["KazaTipi"];
marker.vsegid = locations[i]["vSegID"];
markers.push(marker);
}
});
Displaying 300000 points directly on the map is not the correct approach and will not perform well, especially as more datasets get added to your map.
In addition, sending 32MB of data or more to the browser is bad form, even for a web map application. If you try out e.g. Google Maps with the network panel open, you'll see that you'll barely go over a few MB even after quite some time using it.
There are a couple approaches that web mappers take to counter this:
Use a service such as Geoserver or Mapserver to split up the data into "chunks" based on what is in the the map clients (openlayers, in your case, according to your answer) viewport. This is the best choice if you could potentially have lots of layers or basemaps in future, but is a lot of work to setup and configure.
Write your own implementation of the above in your back-end. For points, this is relatively simple. This is the best choice for something quick with just a couple of points layers.
In both cases, you'll need to configure your points layer in OpenLayers to use the "bbox" strategy, which will tell it to call your API url whenever the viewport changes enough for more features to be loaded. You will also need to set the minimum resolution for your layer so that it doesn't load too many features all at once when zoomed out.
Lastly, with Openlayers, you'll want to use a VectorImageLayer with a VectorSource for this layer, which will improve performance a lot while allowing you to query and edit your point data.
The above should help to improve your mapping performance.
Well, I went with the OpenLayers API, I think it is harder to implement stuff from docs but they have example applications for every feature. You might want to try that, way better performance if your only need is to put some markers and visualize data.

Calling a Javascript method from the Bokeh Google Maps wrapper (fitBounds())

I have a bokeh Google maps plot with several Lat/ Lng data points, and I would like to use the fitBounds() method of the Google Maps v3 API to set the zoom level.
I have a Google Maps plot up and running, displaying on my site and showing the data points, but I need to set the zoom manually.
import bokeh.io
import bokeh.models
import bokeh.plotting
import pandas as pd
data = {
'Latitude [deg]': [18.46, 25.7, 32.3],
'Longitude [deg]': [-66, -80.2, -64.8],
}
data_frame = pd.DataFrame.from_dict(data)
data_source = bokeh.models.ColumnDataSource(data_frame)
mean_lat = data_frame['Latitude [deg]'].mean()
mean_lng = data_frame['Longitude [deg]'].mean()
gmap_options = bokeh.models.GMapOptions(lat=mean_lat, lng=mean_lng, zoom=10, map_type='satellite')
xy_gmap = bokeh.plotting.gmap('SuPeRSeCrEtAPIkey', gmap_options)
xy_gmap.circle(x='Longitude [deg]', y='Latitude [deg]', source=data_source, color="red")
# A callback like this? Could make the call in JavaScript after the page is loaded, and update map zoom??
# xy_gmap.fitBounds(x='Longitude [deg]', y='Latitude [deg]', source=data_source)
bokeh.io.show(xy_gmap)
I would like the bounds of the map to enclose all points in my dataframe, at the lowest zoom possible (as is done in Javascript by fitBounds() ). Currently, the map can only zoom to the manually set level.
As of Bokeh 1.2, there is no built-in way to accomplish this. The only suggestion I can offer is to note that there is a global Bokeh.index on the JavaScript side, and in that there is GMapPlotView for the corresponding GmapPlot that you made. This view has an attribute .map that is the actual Google map object. You could call the fitBounds method on that from JavaScript code. Bokeh GMapPlot objects follow Google's lead wrt to plot bounds, so if they get updated, the axes, etc. should respond.
Otherwise, I can only suggest opening a GitHub issue to discuss adding this as a new feature.
Starting an answer for both methods described by bigreddot (using JS Bokeh.index and Python integration)
Bokeh.index
In the Javascript Console, you can use the following commands (should be self explanatory to get this into some JS code)
> var gmapPlotView;
> for (var property in Bokeh.index) { if (Bokeh.index[property].constructor.name == 'GMapPlotView') {gmapPlotView = Bokeh.index[property];} } // Get the correct object, in the case that you have multiple plots, but only one map plot
> var bounds = gmapPlotView.map.getBounds(); // To start from existing bounds
> var bounds = google.maps.LatLngBounds(); // To start with fresh bounds
> var place = new google.maps.LatLng(45.5983128 ,8.9172776); // Coordinates of place to put bounds, repeat for all points
> bounds.extend(place); // Add each place to the bounds object
> gmapPlotView.map.fitBounds(bounds); // Set the maps new bounds
Note that the Bokeh google maps implementation does not plot your data on the Google Maps data layer, but on a bokeh canvas above the map (that is why there is a lag when panning the map between map tiles and your graphs).
Python Integration
In process....

Leaflet js map only showing a few tiles

I'm trying to create an custom stationary map using the Leaflet JavaScript library and keep running into a major issue where most of the map tiles for the coordinates do not render. I'm defining & showing the map like so
function initmap() {
map = new L.Map('map');
var osmUrl = 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Street_Map/MapServer/tile/{z}/{y}/{x}.png';
var osm = new L.TileLayer(osmUrl);
map.addLayer(osm);
}
var lat = 40.120910;
var lng = -74.978602;
var startLatLng = new L.LatLng(lat, lng);
initmap();
map.setView(startLatLng, 16);
It seems like it should work, but the map div never shows the full map/all tiles. I know there is coverage for this particular area because I've been using another person's service that using this library and map to look at this location. This code is structured based off of their code.
This website is using the exact coordinates, map server, and the leaflet js script and is able to render all tiles fine.
Here's a JSFiddle to show the code (and issue) in action. Any idea why this is happening or how to fix it?
Missing Leaflet CSS: https://npmcdn.com/leaflet#1.0.0-rc.1/dist/leaflet.css
Updated JSFiddle: https://jsfiddle.net/t14rLknv/7/
(BTW you can upgrade to Leaflet 1.0.0-rc.3, new official CDN on unpkg.com, see http://leafletjs.com/download.html)

Plot Centroid of Feature Layer Polygon

Here is the rest service I'm working from:
http://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3
My current call for displaying the feature layer is as follows:
var recLayer = new FeatureLayer("http://sampleserver6.arcgisonline.com/arcgis/rest/services/Census/MapServer/3",{
infoTemplate: recParkTemplate,
outFields: ["STATE_NAME"]
});
map.addLayer(recLayer);
However, instead of plotting the polygon on the map as this is an esriGeometricPolygon. I would rather have it plot on the map like a esriGeometryPoint. I know this method in getting the specific polygon's centroid:
https://developers.arcgis.com/javascript/jsapi/polygon-amd.html#getcentroid
My problem is I can't figure out how to cycle among all polygons in the feature layer and then plot those polygons. I can only point and click and display similar to how this ESRI sample works: https://developers.arcgis.com/javascript/jssamples/util_label_point.html
Thank you for your assistance.
Here is the current site if you would like to take a look at it: http://joshferrell.net/ece_project/
to cycle among all geometries in your feature layer you can do something like this:
recLayer.on("update-end", function changeHandler(evt) {
require(["dojo/_base/array"], function (array) {
array.forEach(recLayer.graphics, function (entry, i) {
console.debug(entry, "at index", i);
});
});
});
inside the loop use the getCentroid and add the result to the map

How to set up the layer order with Google Maps API?

I'm developing a web mapping site (using google maps api 3.0 and javascript) that combines wms layers and ground overlays (uploaded rasters) that are displayed on top of google maps. The software is working well except that I'm having problems controlling the draw order of the layers. I would like to have the wms layer (the NRCS soils layer) displayed on top of the custom raster images, with the google maps as the base layer. Currently, the wms layer displays as expected on top of the google maps layer, but is covered by the raster layer. The question is: does the google maps api allow control of the order that layers are displayed (in my case the vector layer on top of raster layer on top of google maps)? I have tried setting the zindex of the display order, but that has not worked (but I could easily be missing something).
WMS layers are also rasters, not vectors -- I assume you are using an ImageMapType along with your GroundOverlay?
Leaving that aside, there is currently no way to control the layer ordering once they have been added to the map.
As a hack (untested) you may wish to add the layers in the order you wish them to be drawn, with some timeout between... I think this may work (again, untested).
(optional).
how i order it.
first i create layer in object like this.
layer = {};
layer.nrcs_soils= new google.maps.ImageMapType({
getTileUrl: function (coord, zoom) {
return getTileWmsUrl(coord, zoom, "nrcs_soils");
},
tileSize: new google.maps.Size(256, 256),
opacity: 1,
name:'nrcs_soils',
alt:{
layer_name:'nrcs_soils'
,order : 0
},
isPng: true
});
after that i create simple function add layer to map.
add_layer = function(layer_name){
//-- get order from object layer
var order_layer =layer[layer_name].alt.order;
map.overlayMapTypes.insertAt(order_layer ,layer[layer_name]);
}
just call this function for add and order layer from your setting on your object layer.
add_layer("nrcs_soils");

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