I would be very happy if someone could help me on this. i am planing to write a script that simulates a moving car on google maps. simply a marker that is traveling across the roads. the point is that it has to move and turn randomly on the roads, i mean without a end destination. it should just need a starting point and decide on its own where it has to turn.
here for example it moves across the destination: http://econym.org.uk/gmap/example_cartrip.htm
what i need is to give it just one location and it starts to move and turn randomly and continuously.
is that possible. and how can i accomplish that. i would really appreciate if i could get a lead.
PS: at the same time i need to store each moves coordinated in to the database.
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I am using Flutter to write my running app likes Strava. In this app, I used location and google maps plugin for flutter. Everything is good until I call getCurrentLocation every 10s to track my location and receive different LatLng even if I stand still.
Did anybody here face the same problem? I think it probably cause by the GPS's accuraccy issue.
Every few seconds, Android (and ios) gets a new location by either connect to cell towers or connecting to gps satellites. Based on that data it determines the most likely location for you on the globe. Since these measurements are not 100% accurate, every time it recalculates the users location, there will be a slight difference in location. Even if you stand still, your lat-lng values will change slightly. That is normal. You can decide to discard the new value if it is too close to the previous one. maps_toolkit is a good library for calculating the distance between two locations.
I am using Google Direction Service for route drawing by providing it way points (recorded at some specific time interval). While drawing, it, sometimes (may be due to slight error in GPS measurement), it draws like the vehicle took a U turn to reach there. I guess it can be solved only if google ignores road dividers.
For example:
Look at the below picture, my vehicle moves on left road, but due to GPS accuracy issues, it sometimes gives me coordinates on right part of road. And when I give the coordinates to google to draw the the path, it gives me a U - Turn.
Can anybody please tell me how can I solve this issue?
I have lists of between 100 and 10000 GPS location from vehicles driving around during some timespan.
I want to display that on a Google Map, using their API (with the Business licence if that matters).
As I see it, there are 3 options, all with problems:
1) Draw a polyline between all positions. Some positions are not that accurate so it looks like the route hits some buildings next to the road. I know that all positions are on a road. Also, it cuts some corners, and it doesn't look professional.
2) Display just the GPS positions in the map. This is not good either since the GPS positions are off the road (which they shouldn't be).
3) Draw the route using Maps API. This limits us to using 23 waypoints between the start and end positions. The route looks excellent and it follows the road (GPS positions next to the road are moved to the road automatically). But especially for longer time spans, this option means that the route displayed is incorrect (Google guesses the route taken between the waypoints - so from the 10000 GPS positions it only uses 23). And we can't display a clearly incorrect route.
Does anyone have a good/better way to show a driven route on Google Maps that follows the road but takes into account all/many given GPS positions?
Could you not chain the route using the maps API? It's not something I've done before so this answer could be a little vague but would it not be possible to segment your list of coordinates into chunks of 23 fire the requests and then display the resultant routes on the map?
I'm not overly sure on the return format so it may be necessary to mess with the output in order to give the illusion of the route, also you will likely not need to use every coordinate (perhaps exclude those that are within a small distance of each other for example being stuck at lights), otherwise the requests may take a long time.
We've actually moving away from option 3. The reason is that when the positions get moved to the nearest road, that is not always correct (like if you're driving on a parking lot), so since that doesn't always give the correct route, then we'll not take that path.
So I don't know if it's possible to chain several routes in the same map.
I'm trying to build a map with the following algorithm:
Wait for pan or zoom to occurs.
Query for all streets visible in the viewport (extent).
Color every visible street with a predefined color.
Example:
I want to show the numbers of businesses on each street, or the number of crimes committed at each street.
I have a DB which holds this kind of information (streetname, data), but each row doesn't have the location data.
Therefore, after each map zoom or pan, I cannot query all of it by a geographical bounding rectangle, it will be far more efficient to use Google own DB and query it by street names.
I know how to register to pan and zoom events.
I know how to calculate the viewport coordinates.
I know how to color a single street.
How can I get a list of all streets visible in the viewport?
Any other solutions or architectures are welcome.
The preferred solution will not use Google DirectionsService nor DirectionsRenderer since they slow down the map.
My understanding is that what you are asking is not possible from Google API's. Reverse geocoding inside a polygon is not a service they offer. There are some posts on other sites (e.g. https://gis.stackexchange.com/questions/22816/how-to-reverse-geocode-without-google) with the reference gisgraphy.com looking like a pretty neat reverse geocoding tool.
This still does not address your all streets in a polygon problem however. I think your only option would be to get your hands on the data (Open Street Maps) and write the code yourself. Further - if you are going to do this for a large area I would take an approach like I recommended here with grids: https://stackoverflow.com/a/18420564/1803682
I would create my grid elements, and for each street calculate all the grids to which it belongs and store in the database. Then when you search a polygon, you would calculate all the grids the polygon overlaps, and can then test the subset of road data in each of those squares to determine overlap.
I looked into this and abandoned a similar requirement a few months back and still have a desire to implement it. Most of the point/line in polygon work is happening on data created in my application (i.e. not street data) and right now that is the only data I will be including. What I am trying to say is - I hope someone gives you a better answer.
Update:
For what you are asking I still believe you will need to use a mix of your own database based on OpenStreetMap and some kind of grid analysis carried out in advance. If you have some time to commit to the project this should not be too awful to process. The database will be large, and the calculations needed will likely require a significant amount of one-time / upfront processing time. As far as highlighting routes/roads/whatever within the viewport, there are lots of way to accomplish this using the API - example here which I found useful: polyline snap to road using google maps api v3
Also useful: http://econym.org.uk/gmap/snap.htm
Note that one way streets may give some grief if using the directions api to snap to a street and you will likely have to watch for this and correct or reverse the start/end points.
Google would recommend using it's Geocoding Service in order to populate your data base with the co-ordinates. You can then use the LatLng Bounds Class method "contains" to check whether your points lie within the viewport. The advantage of this approach is you only need to geocode the information once and then store this, versus sending coding requests each time the viewport changes.
An alternate efficient way of displaying this kind of data may be to use google fusion tables. this greatly simplifies the integration of the data with the map.
So I am trying to think of a way to facilitate two things. It may end up being a two step process in the end but I was looking for input.
The first thing I need to do is accommodate locations with the same address. The two scenarios that come to mind are businesses that share a location and apartment buildings.
The second thing I need to accommodate is a business/nonprofit with no headquarters, just a town. Right now I just map them to the town center, but if multiple businesses have no headquarters I run into the first problem.
So I did some Googling and found a solution that involved having a list of locations alongside the map so you can click on them and the info window will pop up. This isn't a solution for me though.
What I was thinking of was using the location to map the first point. For the second and points after that moving the marker over .05 degrees or something marginal so that the marker shows up. The inherent problem with that is that what happens if 12 Main Street turns into 13 Main Street?
So any thoughts on what I could do?
Thanks
Levi
There's an extension by Martin Pearman called ClusterMarker that detects any groups of two or more markers whose icons visually intersect when displayed. Each group of intersecting markers is then replaced with a single cluster marker that looks different. The cluster marker, when clicked, simply centres and zooms the map in on the markers whose icons previously intersected.
A more advanced approach to this problem might be SQL - same address = same coordinates...
GROUP BY or HAVING COUNT > 1 ... would let you create multi-record coordinates.
In fact - before you can cluster client-side, you need to send out the data first, which means transferring much more than required in this case, which results in higher loading times and higher RAM utilization client-side ...plus all the useless JS processing of the clusterer.
Client-side clustering is only recommend when the coordinates are close to each other, but not when they are absolutely identical.
Think about it...