c# find nearest element in list / sort by distance

public void TestMinDistance()

{

List<Point> list = new List<Point>()

{

new Point(1, 1),

new Point(2, 1),

new Point(2, 0),

};

Point pivot = new Point(3, 1);

Func<Point, Point, double> DistanceTo = (point1, point2) =>

{

var a = (double)(point2.X - point1.X);

var b = (double)(point2.Y - point1.Y);

return Math.Sqrt(a * a + b * b);

};

Point nearest = list

.Aggregate((x, y) => DistanceTo(x, pivot) < DistanceTo(y, pivot) ? x : y);

Debug.WriteLine(nearest);

// sort by distance

List<Point> sortedList = list

.OrderBy(x => DistanceTo(x, pivot))

.ToList();

sortedList.ForEach(p => Debug.WriteLine(p));

}

https://stackoverflow.com/a/5954005

http://www.vcskicks.com/code-snippet/distance-formula.php