I'm using Google Places to get latitude and longitude for places near a user, and then plotting those points on both Apple Maps (on iOS 6, using MKMapView) and plotting them on Google Maps (using Javascript V3). Now the problem is when I plot them on MKMapView the points are not in their correct positions, while on Google Maps they are. Why is this the case? Shouldn't plotting a latitude/longitude point on a map make it have the same point?
The points are the same. However The image overlays are going to be different. This could be due to the angles that the images where taken at, an we all know that Apple is having some small issues fixing there mapping program. I hope this helps.
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I want to the count of markers based on location using leaflet map
ie,
Say in india
Number of markers in bangalore
number of makers in mysore so on...
only thing i would think of to do this is using contains( point )
which is in the doc
But how to use it to find the maker is in that region as i will not be aware of the coordinates of the region
Is there a way to check like
region.contains(markerLatLang)
Leaflet .contains() works on L.LatLngBounds objects, which are actually a rectangular region. So it tells if your point / marker is within a rectangle or not.
You would need first to retrieve yourself the coordinates of your administrative areas of interest (India, etc.). See https://gis.stackexchange.com/questions/199765/where-to-get-world-wide-detailed-administrative-boundaries
BTW, a simple version of countries boundaries can be: https://github.com/johan/world.geo.json
Then you would probably want to use a more accurate detection method, for example leaflet-pip plugin or turf.js, which will actually check if your point is within arbitrarily shaped polygons, not just a rectangle.
See for instance Leaflet event: how to propagate to overlapping layers
I have a simple Google Map. I've added a marker at a given lat, lng.
I want to use turf.js to calculate a 1km buffer which I can then display as a Google Maps polygon.
The path that turf.buffer() returns is an ellipse. The distance from the marker to the boundary is correct latitudinally. However it is short of 1km longitudinally. It looks like there is a problem with the projection, however both the Google Maps API and turf.js documents state WGS84 is the default projection.
The end game is using turf.js to buffer Points, Polylines and Polygons so I can't just draw a Google Maps circle as a workaround unfortunately. I would consider migrating to Leaflet, however we are already quite invested in developing for the Google Maps API
I've created an htm file here showing the problem
I'm not going nuts. The buffer isnt geodesic so at the equator you get a round buffer and as you move north or south your buffer becomes squashed longitudinally towards the poles. The turf.js team are aware. See https://github.com/Turfjs/turf/issues/110 for full details.
I'm looking at using clipper.js instead. This is a cartesian library (2d) so in the uk i can use osgb eastings and northings. I will also have to flip north and south as clipper assumes we are dealing with standard graphics i.e. The y axis is inverted like in css with 0,0 being the top left.
Im going to use geotools to transform between osgb and wgs.
I would like to add color to each house in the following google map example:
https://www.google.com/maps/#43.0748326,141.3479359,19z?hl=en
I found an example in leaflet that add colors to US states by giving the GeoJson data including the corners coordinates of each state. You can find the example here:
http://leafletjs.com/examples/choropleth.html
I would like to do it with Google Map. Two questions in front of me are:
1. How can I get the corner coordinates of houses?
2. As the number of houses which I want to add color is relatively large, how can I efficiently measure the corner coordinates of these houses?
How can I get the corner coordinates of houses?
You can't. The data in Google Maps API is not available to you, because of technical and legal restrictions.
You'll likely want to do this some other way: for instance, with OpenStreetMap data and one of the many services that visualizes it.
My question is similar to this one on another SE site, which didn't seem to get answered very usefully:
https://gis.stackexchange.com/questions/10741/google-maps-js-api-v3-polygon-formation
I'm trying to shade large areas of the globe in Google Maps V3 using polygons. My issue is that that algorithm decides on its own which part of the map is "inside" the polygon and which is "outside".
From what I've been able to tell, the map always sets the South pole outside the polygon. Example jsfiddle: http://jsfiddle.net/YFJ6a/6/
I'm guessing from earlier questions about filling in the area outside a polygon (eg. Google Maps Polygon Outer Fill) that there's no way to simply invert a polygon. I've had some success in using the method described in the link, combining my polygon with a polygon that tightly circles the South pole:
[new google.maps.LatLng(-89.99,180), new google.maps.LatLng(-89.99,-120),
new google.maps.LatLng(-89.99,-60), new google.maps.LatLng(-89.99,0),
new google.maps.LatLng(-89.99,60), new google.maps.LatLng(-89.99,120),
new google.maps.LatLng(-89.99,180)]
The path above generates a polygon that covers pretty much the entire globe. But this is messy and only works if my shape doesn't actually intersect with this polygon, which I can't guarantee. (It's easy for me to wind up with polygons that cross directly at the pole, for example.)
Is there any cleaner or more direct way to accomplish this?
Apologies if this is dead simple..
I can see that it's possible to draw on an area using overlays, but is it possible to just draw(colour) a location (a pair of longitude and latitude coordinates)?
I need to colour a map by specifying a colour for every location I have available in my database.
I'm also a bit concerned about the speed.
Any ideas/advice welcome!
Thanks
A lat/lon pair represents a point, and a point has zero size. You cannot color something that has no size, therefore you need to represent those points with something bigger than a point, like a marker or a polygon, both of which are overlays.