wgs2utm (version 2)

function similar to Rafael Palacios's deg2utm.m but using formulas from "Map Projections - A Working Manual" by J.P. Snyder (1987) for better precision in Southern hemisphere.

This second version allows forcing UTM zone and hemisphere in input, but can still be used like the previous version in which the function finds the appropriate zone.

Examples:
Lat=[48.866667; 34.05; -36.85 ];
Lon=[2.333056; -118.25; 174.783333];
% data zones:
[x1,y1,utmzone1,utmhemi1] = wgs2utm(Lat,Lon)
% forced zone:
[x2,y2,utmzone2,utmhemi2] = wgs2utm(Lat,Lon,60,'S')