I'm working on a project where I need to display maps. These maps are going to have routes and points of interest, there will be many maps to display in the future. At this moment, the project operates with mysql. At first, I was thinking in keeping the points of interest and the points from the routes in a table in mysql server and display them with leaflet.js and OSM, but doing some research I found information about geoJson to store points and routes, and also i notice that leaflet can display information in geojson format.
I am a novice at Maps topic, so what do you recommended me?
To store points in mysql?
To have a database of geoJson files which store information about any map?
The project is about a Web application where the user will find detailed information about some routes, this information will be displayed in text format(html) and will be accompanied with a map (that will display the route and some points)
We (https://play.google.com/store/apps/details?id=org.aph.avigenie&hl=en) used a sqlite DB on the device to store favourites. We also store OSM (Open Street Maps) data in MySQL. Having the geospatial extensions is helpful; however, we don't use them, we have been able to find ways around having them.
A really useful answer would require some more insights about your application. For example, is your application somehow coupled with a webservice? Is your application itself a web service? In that case, should the various calculation be performed on client-side or server-side? Are you dealing with few POI and routes having not many waypoints? Or are you working on a planetary GIS?
Assuming you probably are somewhere between those last two extremes, you should definitively take a look at:
MySQL spatial extension
or preferably PostGIS
Those will allow you to store lots of data and to efficiently retrieve them.
BTW, remember the earth is not flat. So, storing point is one thing, but displaying them on a flat display will require to use some kind of projection. GeoJSON itself is only a file format. You will definitively require a tool than can handle that for you. That will be one key feature to check, I think.
Related
I have a fairly simple, and what I would think to be common mapping web mapping project to complete. I'm struggling in my selection of a web mapping API. Thus far, I've not been able to one that meets the following requirements.
Able to display thousands of points in one view without choking crippling the browser. To be specific, I'd say I would like to display roughly 30,000 points at one time and still be able to navigate around a slippy map without degraded performance.
Local maps. The web server will run on the local client, so being able to display a map without reaching out to the internet (even if it's a very basic map) is an absolute requirement.
Render dynamic data from a database onto a map (most API's are meeting this requirement).
Draw polygons directly on the map, and export the lat/lon values of all vertices.
In your experience working with map api's, do any of them meet the requirements above?
I've looked at OpenLayers 3, Leaflet, and Polymaps. Aside from reading every piece of documentation ahead of time, I can't discern if any of these would fill all requirements. Again, I'm hoping someone with experience with any API could point me in the right direction.
Thanks!
As for Leaflet:
Thousands of points: you could use one of these plugins:
Leaflet.markercluster, clusters your points into "groups of points" at low zoom levels.
Leaflet MaskCanvas, replaces all your points by a single canvas layer.
Local maps: as long as you provide a way to create image tiles (even on the local machine), most mapping libraries should work.
Dynamic data: depending on what you call "dynamic", all mapping libraries should provide you with built-in methods to display your data.
Drawing polygons and export lat/lon vertices: use Leaflet.draw plugin
OpenLayers 3 would very probably provide you with all these functionalities as well.
First, I'd like to let it be known that this is my first journey into developing mapping applications with such a large set of data. So, I am in way locked into the techniques or technologies listed below...
The Overview
What I am trying to accomplish is the ability to load my company's market information for the United States onto some form of web-based mapping software. Currently I am trying to accomplish this with Google Maps JS api and GeoJSON data, but am not against other alternatives. There are roughly 163 files (ranging from 6MB to 200KB) that I have exported from ArcGIS into GeoJSON files, and then loaded into a database (currently as GeoJSON strings). We have developed a UI that loads the data based on the current map bounds and Max/Min calculations in the corresponding records.
The problem I'm running into is the render time on the map itself, which is annoying when switching between different regions, states, or zoom levels. The API calls to load the data are acceptable in regards to the size of the data being retrieved. My boss said it is great for a proof of concept, but would like to see it much, much faster.
The Questions
What suggestions could you offer to increase the render time?
Are there better options (3rd party libs, techniques, etc) for what I'm trying to accomplish?
It was suggested by a co-worker to export the map shapes and just use the images for overlaying the information based on the coords. Any input on this?
One solution to your problem could be reducing number of vertices in polygon or polyline layers (files) while preserving feature's shape. In that way geoJSON file would be smaller and easier to render.
You can use tools available in ArcGIS for Desktop.
See
How to Simplify Line or Polygon
or
Simplify Polygon
I'm sure there are similar tools in QGIS or any other open source GIS software.
There are other solutions to your problem like prerendering data in map tiles that could be overlayed over Google Maps basemap(s). That is probably the fastest solution but more complicated.
Maybe this could be good starting point.
Just couple of random thoughts.
On one project I worked on I noticed terrible performance with geoJson I loaded via REST service.
I found out that browser's JavaScript engine had hard time parsing large geoJson responses. I finally decided to load data in batches (multiple requests). Performance increased enormously.
I noticed you use 163 files (layers?). Do you display them at the same time (no no no) or you have some control panel to switch layers on/off? If you display them at the same time then performance will suffer for sure and you should look into generating map tiles with thematically grouped layers. In that way you'd come up with couple of tile layers that you can switch on and off.
Also, if data used to generate tiles changes frequently than tiles aren't good idea. Then maybe you should look into Web Map Services. WMS generates maps on the fly from data stored in database. GeoServer supports WMS and it's easy to configure and use.
i would implement a Map on my Homepage.
It should display a route from a fix start point to a variable end point.
We have a database (mysql) which contain adresses (Street and number).
And thats the only way to determine the two points
I have completely no idea how to do that.
is OSM (OpenStreetMap) a good way to do that? But how can i get coordinates from a adress ...
Yes, OpenStreetMap is one possible way of solving your task.
To embed a map based on OSM you should either stick to Leaflet or OpenLayers. Both offer slightly different features but are easy to use. And both can easily display a GPX file (your route) as an overlay on top of the map.
For calculating this route you can choose from one of the many online routers, offline routers or just stick to a library.
Similarly OSM offers a way to convert an address to coordinates. This is called geocoding and can be done using Nominatim.
Remember to check the usage policies if you decide to use any of the web services (routing, geocoding, tiles). For most of these services there are alternative instances available which are run by different companies and have less-strict usage policies. And of course you can also run your local instances of most of these services if you like.
In my web application I have a list of businesses/clients and their information, including their address. I'd like to mark one of them, then get the other businesses/clients that are in a X km radius.
I'd prefer to control the X with a slider, and I'd prefer to display the results on a map as well, but neither point is crucial. How should I go about this? Would Google Maps be a good tool? Where can I find more information, or an example of this?
Google Maps API should work well for this.
In fact combine it with Fusion tables, is even better. FT will host your database, and make making 'spatial' queries against your data easy (ie results within X of Y). FT is even intergrated with the Maps API to display the results of your query direct on the map.
If you want to use an Open Source Javascript library with possibly a bit more flexibility than google maps' API, use OpenLayers - and if you dont want to have to pay the new Google Maps API fees, you can use OpenStreetMap for your background layers. Make your slider with something like jQuery UI or Dojo and link them with some event handling. Job done.
What's your back end application written in? There's assorted geospatial libraries that make spatial queries nice n easy in most languages. A bit of googling should bring them up. I doubt you'll need to go for a full spatial database, but if you do then check out PostGIS - that can do stuff like find all the businesses within Xkm of a major road (once you've got all the data into it of course!).
www.osgeo.org is the best start for open source geospatial software. Lots of web, database, and desktop tools there.
Google Maps doesn't support a local search. It provide only an API to find and set marker and get a direction. It has some beautiful maps, too. What you want is the harvesine formula to look for close targets. Alernatively you can use a spatial extension and search for tiles or cluster of targets. It's just an approximation. I don't thin that FT support the former or the latter. It's just a Sqlite-alike database to store your markers.
Try mysql spatial extensions.If you cannot implement Radius Query which i think you cannot consider strongly to switch to postgresql+postgis.Once you migrate this problem will be solved in 5 minutes.
Also for a custom solution take a look at this answer
Cheers
I want to create an application where users can mark on map location of polluting factories. Google map provides a MAP editor feature. We would like to have our own website like www.toxic-map.org where people could mark these locations. What would be the best approach for this?
Additionally we should be able to backup this database which could be cross checked or used for other purposes.
This will enable us to have little accurate census of such entities and thereby helping us in the fight against these environment harming, illegal factories. Most of our work is focused on developing countries of Asia.
Edited: Google maps is one of the options. I am open to other possible solutions as well. I am looking at something we could do quick prototyping in.
Thank you in advance!!
On the client side, I recommend you to have a look at OpenLayers, a free and open source web mapping framework released under a BSD-style License. It is completely written in Javascript and offers a lot of functionality, including the features that your application may need (Add markers to the map, drag them to adjust the locations, ...).
It also supports dozens of different geographic data formats and services such as WMS, KML or Google Maps.
If you are worried about licensing issues regarding the use of Google Maps, you can use other global data sources like OpenStreetMap or a public WMS if they provide enough coverage of your area of interest.
On the server side, I agree with the answer provided by Daniel Vassallo. I will just add a little detail and recommend you to serve the markers in a standard format natively supported by OpenLayers like KML, GeoJSON or GeoRSS. It will make really easy to draw the markers on the map.
Looks like a really interesting project, I hope you are lucky starting it up.
I seem to remember that there are restrictions to what you can do with the coordinates if you enter them through Google's interface, but if that doesn't bother you then sure, Google might be the way to go. (It may just pertain to geometrical figures entered into Google Earth or something like that.)
Google seems to be in line with your ideology anyway, as they're doing a lot of green power development. Might even be a selling point.
But if you can input the data separately and have Google Maps just display it for you then I wouldn't think they could hold claim to the data.
I think your best bet is to use the Google Maps API instead of the map editor in My Maps.
With some basic JavaScript, you will be able to allow users to drop markers on the polluted locations they would want to tag.
You will need a database on the server-side, and a thin application layer that:
Accepts and validates new markers added by users.
Serves the markers from the database to the browser.
You may want to use AJAX to interact between the browser and the application layer.
I think this type of project would be an excellent candidate to be hosted on the Google App Engine. You will be able to leverage on the simplicity of the webapp framework, and the Google Datastore appears to fit well.
As a side-note, you might be interested in checking out the Heat Map API for Google Maps. I think heat maps would look good in a project like this.
The approach is this:
1. User can drag the marker to the location of toxic factory.
2. A simple form opens to enter details of the toxic factory.
3. The latitude, logitude and other datails are then saved in database.
Please refer www.loppee.com They have a similar solution where user can mark the location of people or places of interest. Loppee uses LeafletJS javascript framework. It is a simple framework. You would be able to develop quick prototype. LeafletJS.com has simple and easy to use code samples.
Additionally, you can enable Geolocation and IP triangulation. Refer: Longitude and latitude value from IP address