#!/usr/bin/env python
'''Calculate convergence angle from UTM coordinates in degrees
Requires `pip install docopt numpy utm km3astro`

Usage:
    get_convergence_angle.py <easting> <northing> <zone> <letter>

Arguments:
    easting   UTM Easting of the site
    northing  UTM Northing of the site
    zone      UTM zone
    letter    UTM letter
'''
from docopt import docopt
from km3astro.coord import convergence_angle
import utm
import numpy

args = docopt(__doc__, version='0.1')
easting =  args['<easting>'] 
northing = args['<northing>']  
zone = args['<zone>']
letter = args['<letter>']

latitude, longitude = utm.to_latlon(float(easting), float(northing), int(zone), letter)
conv_angle = convergence_angle(latitude/180.*numpy.pi,longitude/180.*numpy.pi)*180./numpy.pi 
print("lat, long", latitude, longitude)
print("convergence angle",conv_angle)