I am trying to create a heatmap based on scatter points. Afterwards need to export it to GeoTiff in order to publish it. I was thinking on using Deck.gl Heatmap library to build such a map, but I do not know how to access the data before is rendered.
Is this even possible?
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I want to draw polygons in google maps and for these to be stored in mysql. I then want to be able to upload polylines and see if they intersect with the polygons. Is this possible?
I am not sure if you can do it with google maps, but you can use leaflet and openstreetmaps to develop it.
Using leaflet you can draw polygon and get that value in a textbox and save it in your database.
http://leafletjs.com/examples/quick-start.html
Try this example
https://github.com/Leaflet/Leaflet.draw
I am working on a GIS Application. What progress i have done is that i have loaded a KML Layer on Google MAPS API and i am plotting the routes between the points. This is GUI Part. Now how do i save the latitudes and longitudes which i click on the maps in database and later on retreive them to display it on the maps??. I am using POSTGRE SQL as Database and Google Maps API for plotting the points. Should i capture the latitudes and longitudes on onclick function? And after capturing what are the next steps?. And what datatype can be used to capture Geospatial Data in PostgreSql. Please guide.
You can use Geography or Geometry datatype to store your polylines. Take a look at this page if you're not familiar with them. As you write it, you can capture latitude and logitude of each clicked point during onclick event, then construct your object and store it in your DB.
Depending on your needs, you can also determine that a polyline is a list of points, which are defined by a latitude and a longitude. Create a table with three fields (idRoute / lat / lng) and store all your points in this table. Then, to display your route in your map, just load all the points where idRoute = route you want to display.
I am playing around with the Google Maps JS API, Mapbox API and I was curious, how are markers actually added to a map? Does the backend code take a set of map tiles, convert the edges to lat/long, and then simply interpolate the lat/long of the marker coordinates along the X and Y axes?
I ask because I am building an application that would need 1000-5000 simultaneous markers, and want to build my own backend system as using the Google Fusion Tables API can get expensive.
how are markers actually added to a map
In the simplest implementation, markers are represented as GeoJSON or similar, and requested from the server, and then 'projected' into screen coordinates from lat/lon; see node-sphericalmercator for one example of that logic.
For the 'performant' case, like TileMill or Google's pre-rendering mode, markers are baked into raster tiles, PNG files, that show them and their locations, and you do magic like UTFGrid to do interaction.
Note that both of these are compromises: you can get speed, flexibility, and simplicity, but it's very hard to get all at the same time.
I am working on application in which i have integrated drawing polygon functionality. Drawing polygon functionality is working great but i need to built another functionality where user can save the polygon search. For that to that to work i need to save polygon paths points which i have already saved now i need to know is there function in gmap to which we pass draw polygon points and it draws the polygon automatically or is there any workaround to built this functionality.
Looking forward for your response.
With OpenLayers, I'm trying to use a Google map layer as a base layer for a map which will display an overlay layer of custom data. My custom layer seems to have an offset related to the Google's layer and both have different projection values (as you may know google's projection is EPSG:900913, but mine is EPSG:32721)
Any ideas of how this match can be achieved?
Thanks in advance!
Since you mentioned that your layer is a WMS you can't use OpenLayers functions to reproject data as it can only be used on vector data, not images.
One possible solution could be Cascading feature in Geoserver that would dynamically reproject your WMS to EPSG:900913. You can find more information about that here