I'm using Google Maps for my campus map and I already have all the overlays for the buildings done along with javascript to open windows when clicked on the overlay, etc. The next problem I'm trying to tackle is how to get directions from point A to point B (using point A as geolocation). On my campus there is about 2.5 miles+ of sidewalks but they aren't defined paths in google maps, so i cannot use the built in directions which Google maps offers.
Is there any way i can make it so it displays directions from point A to point B while making it so it displays a path along a sidewalk?
Thanks in advance.
EDIT: I already have the geolocation working also.
If Google doesn't know about the sidewalks, you will have to do the drawing yourself. You will need to store information about the sidewalks in a database, then come up with a routing algorithm, then draw a line (using the Polyline class).
For routing algorithms, you might be able to get away with using Dijkstra's algorithm
http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm
or you could try A*
http://en.wikipedia.org/wiki/A*_search_algorithm
or one of the other algorithms you can find in the Wikipedia sidebar on the Dijkstra and A* pages.
Polyline documentation:
https://developers.google.com/maps/documentation/javascript/overlays#Polylines
Related
I'm trying to find in the Google Maps documentation a way to search for a place and get it's GeoJson polygon but I got no luck finding something like that.
My goal is to create a search bar to search places and then send the geojson polygon to our back-end. I don't want to draw it on a map or anything front-related.
Nominatim is doing exactly what I want but Nominatim policy is very restricted so before I go for an alternative, I wanted to check if Google Maps could provide the same (especially since searching for a country on Google Maps retrieve the polygon and draw it on the map).
Thanks for your help !
Unfortunately Google Maps APIs don't expose any polygons data of geographic features. You can see very old feature request in the Google issue tracker to add this functionality, however it looks like Google didn't set high priority on this task:
https://issuetracker.google.com/issues/35816953
Feel free to star the public feature request to express your interest and subscribe to further updates from Google.
You should get polygons from other sources.
I am developing GPS based Location reminder in j2me. I am little bit confuse to which maps i use??.....Google maps & Nokia maps. Which one allows me good working... The working of my app are as follows :-
-User will provide a string to app to search a place of his/her desire.
-Then according to given string app will show a place on map by pointing marker on map.
-User can save that place or he/she can select a near by place rather than searched place by clicking on map or any other way.
-app will save that searched place coordinates & remind when it reached to near that place.
-When app remind to user about already stored place... that place should show on map by pointing an marker along with the how far he is from his destination.
The real choice here lies in whether to use a RESTful API like the Google Static Maps (or Nokia's RESTful Maps) or to use a native Java ME mapping library plugin such as the Nokia Maps API for Java ME. The latter has several major advantages:
Static mapping services such as the Google Static Maps API or Nokia's
RESTful Map API do not cache or tile the images when requested,
therefore each request involves a round trip to the server. If the
map on a mobile application needs to be refreshed at any time, using
a caching library will result in a reduction in network traffic after
around three maps have been displayed. An explanation of this can be
found here
As the name implies, Google's Static Maps API can only retrieve over
http static images for a requested coordinate point, image size,
image type and zoom level. Newer libraries offer additional
functionality out of the box offering dynamic Map content and touch
support, where the user can move around his/her current position,
zoom in, zoom out, modify the view mode to satellite or translate an
address to a coordinate point and show that on the map, among others.
This abstraction of the underlying functionality is hidden from the
developer so much less coding is needed in order to achieve the same
result .
Terms and Conditions for Nokia Maps are easier to fulfil than
Google - No legal restrictions of using the API outside a web browser
application or need to provide a link to the native Google Maps App
(if there is one), or to Google Maps (if there isn't one).
Nokia currently offer higher free daily request limits. Nokia Maps
API for Java ME supports up to 50,000 render requests per day and per
unique IP address (as of January 2012), for Nokia Developer
registered users (free of charge) while the limit for Google's Static
Maps API is currently 1000 unique (different) image requests per
viewer per day.
A couple of years ago there wouldn't be a choice, only RESTful solutions existed, but these days I would say a static http solution should only be used if you want a simple single image
As an abstraction of the underlying services, there are already a full set of examples to cover most of your use cases:
-User will provide a string to app to search a place of his/her desire.
-Then according to given string app will show a place on map by pointing marker on map.
http://www.developer.nokia.com/Commu...PI_for_Java_ME
-User can save that place or he/she can select a near by place rather than searched place by clicking on map or any other way.
Maybe you need to use a draggable marker:
http://www.developer.nokia.com/Devel...ples/#standard
Or react to the touch and find a Geocoordinate:
http://www.developer.nokia.com/Commu...PI_for_Java_ME
-app will save that searched place coordinates & remind when it reached to near that place.
This is known as geofencing and is covered by the Location API:
- http://www.developer.nokia.com/Resou...ty-events.html
-When app remind to user about already stored place... that place should show on map by pointing an marker along with the how far he is
from his destination.
Showing a Map with a Marker
http://www.developer.nokia.com/Devel...ples/#standard
For distance calculations, I guess you'd be after the ROUTING example
http://www.developer.nokia.com/Devel...mples/#routing
http://www.developer.nokia.com/Commu...g_with_Java_ME
Now you could re-write and all these services from scratch using RESTful APIs (and then go about debugging your code) , but I'm sure you'll agree it would be much easier to use an existing, working and tested framework for the low level plumbing and then just write your code on top using the services.
It is possible to encapsulate RESTful service in Java ME. As an example, added below is a screenshot from an app encapsulating the suggestion service
It is just a lot easier when someone else has already done this work for you and placed it in a library.
I'm looking for a solution to be able determine landscape type by a given coordinate, for example check if current position is water/forest/town/road and so on. I found google.maps.MapTypeStyleElementType object specification in the Google Maps specification, but not sure if it could help me or not.
Probably, there are some another Maps API with such functioality? Or maybe I should refer to the different types of offline maps?
Nope, the link you send is just for styling the proper features, not to tell which feature is at a given coordinate. If you are interested in landscape, then Corine Land Cover is the thing you are looking for. It describes the types of biotops like forest, water, but also land use - meadow, field, buildings etc. However, I don't know if there is such an online service where you could query particular coordinates. Other solution for you would be to import these GIS layers (they are freely available) to your own gis map server. Maybe this is partially solved as there are e.g. projects how to incorporate these into openstreetmap.
Well not quite, but you could get close to what you're looking for by using the Google Reverse Geocoder and the Google Places API
Google Reverse Geocoding
http://code.google.com/apis/maps/documentation/geocoding/#ReverseGeocoding
If you send the service a geocode it will send back an address type and/or one of several adress components http://code.google.com/apis/maps/documentation/geocoding/#Types
Google Places API
http://code.google.com/apis/maps/documentation/places/
You could use the Google places API to search for for what's near. If the geocode is in the middle of the lake, the Places API may return something like "Lake Michigan" and then you'd know the terrain obviously.
I'm reading through Google Maps API documentation and I wonder if such a think is possible:
I specify the point (by coords)
I search for all roads, and junctions around the node (say in 1km radius)
I get parameters for the streets around (polyline coords)
Is it reachable, or google do not share that data?
Thanks in advance
Rafal
I can image writing up a little script that generates a bunch of random points within a 1km radius and then performs directions services via Google Maps API to obtain all possible routes and thus streets within a 1km radius. However, this is problematic since it is kinda against the Google Maps TOS of displaying this information only on a map within a website and not extracting data for you personal use as this would be.
A better approach would be looking into utilizing Open Street Map data where you can download street data from a specific viewport. If buying street network data is an option, you can go to a commercial outlet such as NAVTEQ or PTV which post-processes NAVTEQ data to a format for use in the transport modeling software package you mention on your blog.
I was wondering if anyone knew of any map APIs that offer topographical or relief data? I've had a quick look at Google and Bing APIs, but could find nothing there.
Google allow you to view a map as TERRAIN, which means you can see the topography of a map, but I want to be able to get at that data - i.e. if I were to draw a line between 2 points on Google Maps, I want to know how high above see level points along that line are.
Is this possible with any map APIs out there?
Thanks for your time!
Here's a simple example of height along a route.
I use USGS to obtain the elevation data, Google Maps API to plot the route and Google Charts to draw the elevation profile.
Full details in the associated tutorial.
Here are a few web services that provide elevation data:
USGS Elevation Query Web Service
EarthTools
GeoNames
Also, this site can search each of them