I am getting line latitude & longitude as
LINESTRING(1491215.4689647 6893983.2031826,1494163.0718675 6894785.7919795)
after seeing this solution.
how to get points return from OpenLayers.Control.DrawFeature
Now what I want to do is that I want to display start point & end point on my web page.
So how can I extract latitude & longitude from here so that I can show it in my page.
If your linestring is already in OpenLayers, there is no reason to convert it to WKT. Linestring geometry contains array of Points. You can access components of geometry in several ways, for example:
drawControls[key].events.register('featureadded', drawControls[key], function(f) {
// First point
var firstPointGeom = f.feature.geometry.components[0].clone();
// Last point
var secondPointGeom = f.feature.geometry.components[f.feature.geometry.components.length - 1].clone();
// Now you got geometries, let's create features from them...
var firstPointFeat = new OpenLayers.Feature.Vector(firstPointGeom);
var secondPointGeom = new OpenLayers.Feature.Vector(secondPointGeom);
yourVectorLayer.addFeatures([firstPointFeat, secondPointGeom]);
});
Pay attention - this works with LineStrings. Probably it's not necessary to go into detail about clone(), it's up to particular use case, whether you need it, or you can use just var firstPointGeom = f.feature.geometry.components[0];
Thats WKT format, you're looking at. You'll potentially need to reproject those coordinates to the target projection if they are not in the same projection. After than, you should be able ot ask openlayers for the points of any given geometry using the base geometry functionaily. Get the point array from the linestring instance and iterate over it. Make sure you know the right coordinate order for your projection / data model.
Hope that helps!
Related
I have a scenario in my JavaScript application where I have the coordinates of a starting point which consist of Latitude and Longitude, similarly an ending point with it's respective coordinates.
Now I need to search for a location which basically provides with a set of coordinates and find if the recently entered location lies in between the previously mentioned starting point or ending point. However, the location does not need to match exactly within the points of the path of the start and end point. That is even if the location lies around the distance of say 2-3 km from the derived path, it should give a match.
I believe that we can create a triangle by providing three coordinates i.e start-point, end-point and a third point. So once the triangle is formed we can use google.maps.geometry.poly.containsLocation method to find if our searched location is present inside this triangle.
So my question is how can we get a third point to create a triangle which will provide locations that are nearby within 2-3 km from start to end point.
Else is there any alternate approach to deal with my use case?
Use googlemap's geometry library
This function specifically
isLocationOnEdge
Here's an example
0.001 tolerance value would be 100m
var isLocationNear = google.maps.geometry.poly.isLocationOnEdge(
yourLatLng,
new google.maps.Polyline({
path: [
new google.maps.LatLng(point1Lat, point1Long),
new google.maps.LatLng(point2Lat, point2Long),
]
}),
.00001);
Please note that the following answer assumes Plane Geometry where you should be using Spherical Geometry instead. Although this will be fine for less accurate purposes (like approximate distance, etc..)
It seems more of a geometry question than a programming question. A triangle like you mentioned won't be able to cover a straight line path in a uniform way. The situation can be thought of more like a distance between point and a line problem (Refer the given diagram
Here you can just find the distance between point C and line AB which you can check whether it's below 2.5 KMs (I've omitted all the units and conversions for simplicity)
Please note that you will also need to convert the distances from radian to appropriate units that you require using haversine formula, etc. which is not a trivial task (https://www.movable-type.co.uk/scripts/latlong.html).
I have used the point based clustering http://bingmapsv7modules.codeplex.com/wikipage?title=Point%20Based%20Clustering
This is great for clustering. However, I am trying to find the longitude latitude of a cluster which contains first pushpin every 5 second using setInterval...obviously I am just simplifying the scenario..
var pushpin = pinLayer[0]; grabbing first story of the pin
var currentClusterIndex = pushpin._clusterIndex; // get the cluster index
var currentCluster = pinLayer.GetPinByClusterIndex(currentClusterIndex);// get cluster info
var currentLatitude = currentClusterLocation.latitude; // get latitude
var currentLongitude = currentClusterLocation.longitude; // get longitude
Now the latitude and longitude is correct when the map loads, but right after user interaction it's rarely correct, it's giving latitude longitude of different cluster.
Could someone possibly help with this?
It's not 100% clear what you want to do. Your code seems to indicate you want to take a pushpin that's on the map and get it's cluster index and use that to get a reference the pushpin. This will just give you a reference the pushpin you are ready have. I suspect you want to get the data for the pushpin which you can easily do by passing the cluster index into the GetDataByClusterIndex method. This will return an array of all the raw data that is in cluster. You can then grab the item you want and get it's original coordinate.
I am using VEMap API. I have the latitude and longitude of the top left point and the bottom right point (bounding box) of a map. I want to get the center point. What is an easy way to do that? I couldn't find a solution by searching on Google.
What I was thinking is that if I can define the map using the two points mentioned above, then I can get the center very easily:
// JavaScript code snippet
var center = map.GetCenter();
var lat = center.Latitude;
var lng = center.Longitude;
Is there a way to call the constructor of map object and pass the two coordinates I have?
Thanks.
The simple answer would be add the latitudes and divide by two, and do the same for longitudes. They are straight lines.
Is there any reason you can't use the VEMap.GetCenter method after the map has been constructed? This way regardless of the viewpoint it will be correct. If you're using the default constructor you can pass in your bounding box, and then call getmap after the object is instantiated.
http://msdn.microsoft.com/en-us/library/bb412539.aspx
I want to zoom to a particular house in the google mapS, but when I provide its bounds and lattitude and longitude, it does not show images as well as the particular house. Can anyone provide the solution for this?
Solution would be probably to transporm coordinates first. Unfortunately when You pass coordinates to OpanLayers.LonLat(lon,lat) it is supposed to be WGS:84, while OpenLayer.Bounds() needs coordinates given in EPSG:900913.
You should then use Proj4js.transform and pass transformed coordintes in EPSG:900913
You can transform it like this one:
var map = new OpenLayers.Map('map');
var location.transform(map.getProjectionObject(), new OpenLayers.Projection("EPSG:900913"));
i need some help with google map api v3 markers.
I got an array which contains coordinates i retrieve from a file. I am trying to traverse the array, and plot them using the markers.
Traversing the array to retrieve the coordinates is not a problem, however, when i start using the coordinates to plot on google map. i realise that i am getting (NaN, NaN) as the coordinates.. Because of this, i am not able to do the plotting.. any idea why isit? Thanksss
my codes so far:
var temp = new google.maps.LatLng(myObject[o]);
retrieverouteMarker(temp);
The constructor for LatLng takes two arguments (the latitude and longitude of the point), so this line is clearly wrong:
var temp = new google.maps.LatLng(myObject[o]);
Of course, since we have to idea what myObject is, or what the function retrieverouteMarker does, there isn't much more we can do to help.