Android : determine zoom level from circle

Question

I am using this code for determining zoom level from circle , but it's not returning valid zoom level,what is the problem?
I want to set map zoom level for display all part of circle.

public float getZoomLevel(Circle circle) 
{
    float zoomLevel = 11;
    if (circle != null) {
        double radius = circle.getRadius() + circle.getRadius() / 2;
        double scale = radius / 500;
        zoomLevel = (float) (16 - Math.log(scale) / Math.log(2));
    }
    return zoomLevel;
}

If you want to fit your circle into the map, you can try this method: http://stackoverflow.com/a/17278527/4195406 — ztan, Mar 10 '15 at 16:28

score 3 · Answer 1 · answered Mar 10 '15 at 16:21

3

I fixed it with Math.floor and using integer instead of float

public int getZoomLevel(Circle circle) 
{
    int zoomLevel = 11;
    if (circle != null) 
    {
        double radius = circle.getRadius();
        double scale = radius / 500;
        zoomLevel = (int) Math.floor((16 - Math.log(scale) / Math.log(2)));
    }
    return zoomLevel ;
}

answered Mar 10 '15 at 16:21

Ali Hasanzade

151
15

any idea what the 500 scale factor stands for ? how did you find that ? – j2emanue Sep 02 '19 at 08:35

Android : determine zoom level from circle

1 Answers1