Convert Degrees/Minutes/Seconds to Decimal Coordinates

user_98814 0
Viewed 49993

In one part of my code I convert from decimal coordinates to degrees/minutes/seconds and I use this:

double coord = 59.345235;
int sec = (int)Math.Round(coord * 3600);
int deg = sec / 3600;
sec = Math.Abs(sec % 3600);
int min = sec / 60;
sec %= 60;

How would I convert back from degrees/minutes/seconds to decimal coordinates?

c#
7 Answers

CoordinateSharp is available as a Nuget package and can handle Coordinate conversions for you. It even does UTM/MGRS conversion and provides solar/lunar times relative to the input location. It's really easy to use!

Coordinate c = new Coordinate(40.465, -75.089);

//Display DMS Format
c.FormatOptions.Format = CoordinateFormatType.Degree_Minutes_Seconds;
c.ToString();//N 40º 27' 54" W 75º 5' 20.4"
c.Latitude.ToString();//N 40º 27' 54"
c.Latitude.ToDouble();//40.465

Coordinate properties are iObservable as as well. So if you change a latitude minute value for example, everything else will update.

user_31332490

For those who prefer regular expression and to handle format like DDMMSS.dddS This function could easily be updated to handle other format.

C# 

Regex reg = new Regex(@"^((?<D>\d{1,2}(\.\d+)?)(?<W>[SN])|(?<D>\d{2})(?<M>\d{2}(\.\d+)?)(?<W>[SN])|(?<D>\d{2})(?<M>\d{2})(?<S>\d{2}(\.\d+)?)(?<W>[SN])|(?<D>\d{1,3}(\.\d+)?)(?<W>[WE])|(?<D>\d{3})(?<M>\d{2}(\.\d+)?)(?<W>[WE])|(?<D>\d{3})(?<M>\d{2})(?<S>\d{2}(\.\d+)?)(?<W>[WE]))$");

private double DMS2Decimal(string dms)
            {
                double result = double.NaN;            

                var match = reg.Match(dms);

                if (match.Success)
                {
                    var degrees = double.Parse("0" + match.Groups["D"]);
                    var minutes = double.Parse("0" + match.Groups["M"]);
                    var seconds = double.Parse("0" + match.Groups["S"]);
                    var direction = match.Groups["W"].ToString();
                    var dec = (Math.Abs(degrees) + minutes / 60d + seconds / 3600d) * (direction == "S" || direction == "W" ? -1 : 1);
                    var absDec = Math.Abs(dec);

                    if ((((direction == "W" || direction == "E") && degrees <= 180 & absDec <= 180) || (degrees <= 90 && absDec <= 90)) && minutes < 60 && seconds < 60)
                    {
                        result = dec;
                    }

                }

                return result;

            }
user_6179700
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