Quick calc to determine centerpoint and radius of circle enclosing a bounding box (helper to query Redis geospatial data)

minimalenclosingcircleradius.cs

using System;
using Microsoft.SqlServer.Types;
using System.Data.SqlTypes;

namespace circleradius
{
    class Program
    {
        static void Main()
        {
            SqlServerTypes.Utilities.LoadNativeAssemblies(AppDomain.CurrentDomain.BaseDirectory);

            double lat1 = 15;
            double lng1 = 11;
            double lat2 = 35;
            double lng2 = 32;

            string lineString = string.Format("LINESTRING({0} {1}, {2} {3} )",lat1,lng1,lat2,lng2);
            string rectangle = string.Format("POLYGON(({0} {1}, {0} {3}, {2} {3}, {2} {1}, {0} {1}))", lat1, lng1, lat2, lng2);
            
            //make bounding box and hypothenuse
            SqlGeometry bbox = SqlGeometry.STGeomFromText(new SqlChars(new SqlString(rectangle)), 4326);
            SqlGeometry bboxDiagonal = SqlGeometry.STGeomFromText(new SqlChars(new SqlString(lineString)), 4326);
            
            //get half length of diagonal (1/2 hypothenuse)
            double circleRadius = double.Parse((bboxDiagonal.STLength() / 2).ToString());
            
            //get centerpoint of bounding box
            SqlGeometry circleCenter = bbox.STCentroid();
            
            //not necessary for further spatial work, so just here to prove calc.
            SqlDouble a = circleCenter.STX;
            SqlDouble b = circleCenter.STY;
            
            Console.WriteLine("r="+circleRadius);
            Console.WriteLine("centerpoint: ("+a+" "+b+")");
            Console.ReadLine();

        }
    }
}