NAME
    Geo::Coordinates::DecimalDegrees - convert between
    degrees/minutes/seconds and decimal degrees

SYNOPSIS
      use Geo::Coordinates::DecimalDegrees;
      ($degrees, $minutes, $seconds, $sign) = decimal2dms($decimal_degrees);
      ($degrees, $minutes, $sign) = decimal2dm($decimal_degrees);
      $decimal_degrees = dms2decimal($degrees, $minutes, $seconds);
      $decimal_degrees = dm2decimal($degrees, $minutes);

DESCRIPTION
    Latitudes and longitudes are most often presented in two common formats:
    decimal degrees, and degrees, minutes and seconds. There are 60 minutes
    in a degree, and 60 seconds in a minute. In decimal degrees, the minutes
    and seconds are presented as a fractional number of degrees. For
    example, 1 degree 30 minutes is 1.5 degrees, and 30 minutes 45 seconds
    is 0.5125 degrees.

    This module provides functions for converting between these two formats.

FUNCTIONS
    This module provides the following functions, which are all exported by
    default when you call "use Geo::Coordinates::DecimalDegrees;":

    decimal2dms($decimal_degrees)
        Converts a floating point number of degrees to the equivalent number
        of degrees, minutes, and seconds, which are returned as a 3-element
        list. Typically used as follows:

          ($degrees, $minutes, $seconds) = decimal2dms($decimal_degrees);

        If $decimal_degrees is negative, only $degrees will be negative.
        $minutes and $seconds will always be positive.

        If $decimal_degrees is between 0 and -1, $degrees will be returned
        as 0. If you need to know the sign in these cases, you can use this
        longer version, where $sign is 1, 0, or -1 depending on whether
        $decimal_degrees is positive, 0, or negative:

          ($degrees, $minutes, $seconds, $sign) = decimal2dms($decimal_degrees);

    decimal2dm($decimal_degrees)
        Converts a floating point number of degrees to the equivalent number
        of degrees and minutes which are returned as a 2-element list.
        Typically used as follows:

          ($degrees, $minutes) = decimal2dm($decimal_degrees);

        If $decimal_degrees is negative, only $degrees will be negative.
        $minutes will always be positive.

        If $decimal_degrees is between 0 and -1, $degrees will be returned
        as 0. If you need to know the sign in these cases, you can use this
        longer version, where $sign is 1, 0, or -1 depending on whether
        $decimal_degrees is positive, 0, or negative:

          ($degrees, $minutes, $sign) = decimal2dm($decimal_degrees);

    dms2decimal($degrees, $minutes, $seconds)
        Converts degrees, minutes, and seconds to the equivalent number of
        decimal degrees:

          $decimal_degrees = dms2decimal($degrees, $minutes, $seconds);

        If $degrees is negative, then $decimal_degrees will also be
        negative.

    dm2decimal($degrees, $minutes)
        Converts degrees and minutes to the equivalent number of decimal
        degrees:

          $decimal_degrees = dm2decimal($degrees, $minutes);

        If $degrees is negative, then $decimal_degrees will also be
        negative.

CAVEATS
    The functions don't do any sanity checks on their arguments. If you have
    a good reason to convert 61 minutes -101 seconds to decimal, go right
    ahead.

AUTHOR
    Walt Mankowski, <[email protected]>

COPYRIGHT AND LICENSE
    Copyright 2003-2024 by Walt Mankowski

    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself.

THANKS
    Thanks to Andy Lester for telling me about pod.t

    Thanks to Paulie Pena IV for pointing out that I could remove a division
    in decimal2dms().

    Thanks to Tim Flohrer for reporting the bug in decimal2dms() and
    decimal2dm() when $decimal_degrees is between 0 and -1.