Converting latitude and longitude to decimal values

Question

To parse your input use the following.

function ParseDMS(input) {
    var parts = input.split(/[^\d\w]+/);
    var lat = ConvertDMSToDD(parts[0], parts[1], parts[2], parts[3]);
    var lng = ConvertDMSToDD(parts[4], parts[5], parts[6], parts[7]);
}

The following will convert your DMS to DD

function ConvertDMSToDD(degrees, minutes, seconds, direction) {
    var dd = degrees + minutes/60 + seconds/(60*60);

    if (direction == "S" || direction == "W") {
        dd = dd * -1;
    } // Don't do anything for N or E
    return dd;
}

So your input would produce the following:

36°57'9" N  = 36.9525000
110°4'21" W = -110.0725000

Decimal coordinates can be fed into google maps to get points via GLatLng(lat, lng) (Google Maps API)

Corrected the above functions and made the output an object.

function ParseDMS(input) {
    var parts = input.split(/[^\d\w\.]+/);    
    var lat = ConvertDMSToDD(parts[0], parts[2], parts[3], parts[4]);
    var lng = ConvertDMSToDD(parts[5], parts[7], parts[8], parts[9]);

    return {
        Latitude : lat,
        Longitude: lng,
        Position : lat + ',' + lng
    }
}


function ConvertDMSToDD(degrees, minutes, seconds, direction) {   
    var dd = Number(degrees) + Number(minutes)/60 + Number(seconds)/(60*60);

    if (direction == "S" || direction == "W") {
        dd = dd * -1;
    } // Don't do anything for N or E
    return dd;
}

My tweaked version coerces the string parts into Numbers so that they can actually be added together rather than concatenated. It also handles decimal values which are common for the Seconds component:

function ParseDMS(input) {
    var parts = input.split(/[^\d\w\.]+/);
    var lat = ConvertDMSToDD(parts[0], parts[1], parts[2], parts[3]);
    var lng = ConvertDMSToDD(parts[4], parts[5], parts[6], parts[7]);
}

The following will convert your DMS to DD

function ConvertDMSToDD(degrees, minutes, seconds, direction) {
    var dd = Number(degrees) + Number(minutes)/60 + Number(seconds)/(60*60);

    if (direction == "S" || direction == "W") {
        dd = dd * -1;
    } // Don't do anything for N or E
    return dd;
}

here is my take on this:

function parse_gps( input ) {

if( input.indexOf( 'N' ) == -1 && input.indexOf( 'S' ) == -1 &&
    input.indexOf( 'W' ) == -1 && input.indexOf( 'E' ) == -1 ) {
    return input.split(',');
}

var parts = input.split(/[°'"]+/).join(' ').split(/[^\w\S]+/);

var directions = [];
var coords = [];
var dd = 0;
var pow = 0;

for( i in parts ) {

    // we end on a direction
    if( isNaN( parts[i] ) ) {

        var _float = parseFloat( parts[i] );

        var direction = parts[i];

        if( !isNaN(_float ) ) {
            dd += ( _float / Math.pow( 60, pow++ ) );
            direction = parts[i].replace( _float, '' );
        }

        direction = direction[0];

        if( direction == 'S' || direction == 'W' )
            dd *= -1;

        directions[ directions.length ] = direction;

        coords[ coords.length ] = dd;
        dd = pow = 0;

    } else {

        dd += ( parseFloat(parts[i]) / Math.pow( 60, pow++ ) );

    }

}

if( directions[0] == 'W' || directions[0] == 'E' ) {
    var tmp = coords[0];
    coords[0] = coords[1];
    coords[1] = tmp;
}

return coords;

}

This function doesn't handle all types of lat / long types, but it handles the following formats:

-31,2222,21.99999
-31 13 13 13.75S, -31 13 13 13.75W
-31 13 13 13.75S -31 13 13 13.75W
-31 13 13 13.75W -31 13.75S
36°57'9" N 110°4'21" W
110°4'21" W 36°57'9"N

Which is what i needed.