Converting circle to LatLngBounds

[Nico]

Hello,

my main intention with my application is to spot given point of
interests in the radius of a 5km circle. To do that I had to convert
the circle to a LatLngBounds Object, which doesn't seem to do the
trick.

For the purpose of testing I made a new Marker, with the latlng
coordinates of the north-east corner of the bound, but this marker is
totally out of the circle and I don't know why.

It would be very nice if someone could take a look at my sourcecode:

http://nicojensen.kilu.de/poiRecognition.html

Sorry for the bad english. I hope people understand what I want. :)

Nico

[Andrew Leach]

On 13 July 2011 12:14, Nico <nico.j...@googlemail.com> wrote:
>
> my main intention with my application is to spot given point of
> interests in the radius of a 5km circle. To do that I had to convert
> the circle to a LatLngBounds Object, which doesn't seem to do the
> trick.

It won't, as you found.

> For the purpose of testing I made a new Marker, with the latlng
> coordinates of the north-east corner of the bound, but this marker is
> totally out of the circle and I don't know why.

The bounding box of a circle is a square which touches the circle at
four points. There will be areas in the corners of the square which
are outside the circle.

To find whether a point is within a circle, simply find the distance
between the point and the centre of the circle. If it's less than the
radius it must be inside the circle. You don't need bounding boxes at
all.

[Nico]

I already thought about something like that, but I don't know how to
implement that. How should I measure the distance between the two
points? Is there some kind of method I can use or do I have to
implement it myself somehow? In that case I probably have to convert
the measurements somehow .. Honestly I dont know where to start and it
would be very, very nice of you if you could give me a hint.

[Andrew Leach]

Hint: http://code.google.com/apis/maps/documentation/javascript/geometry.html

var LL1=new google.maps.LatLng(...,...);
var LL2=new google.maps.LatLng(...,...);
var d=computeDistanceBetween(LL1,LL2);

Note that you need to explicitly load the Geometry library, it's not
part of the basic API.

[Nico]

Thanks for the help, but somehow it still doesn't work. Feeling really
stupid right now ...

I got my first coordinate via the Geolocation API and the second one I
defined myself .. which might be the problem.

var latlng = new google.maps.LatLng(position.coords.latitude,
position.coords.longitude);
var latlng2 = new google.maps.LatLng(51.43545462624757,
6.770839691162109);
var d = computeDistanceBetween(latlng,latlng2);

In the head I replaced the former googlemaps src with this one:

src="http://maps.googleapis.com/maps/api/js?
sensor=true&libraries=geometry"

Thanks in advance

[Andrew Leach]

On 13 July 2011 14:28, Nico <nico.j...@googlemail.com> wrote:
> Thanks for the help, but somehow it still doesn't work. Feeling really
> stupid right now ...

Not enough information. What "doesn't work"? What errors are you seeing?

Please follow the posting guidelines and post a link. Can't debug a
code listing.

[Nico]

The page is still the same:

http://nicojensen.kilu.de/poiRecognition.html

As for errors. There is only one in the script tag:
unescaped & or unknown entity "&libraries"

Which doesnt make much sense, as I just copied it from an example,
that I found.