#!/usr/bin/env python
"""
====================================
Command-line interface to tidynamics
====================================

The program reads in data from the file input_file (using np.loadtxt from
NumPy) and performs the selected action on the data, chosen in:

* acf for the autocorrelation function
* msd for the mean-square displacement

The program writes the result in the file output_file using the function
np.savetxt from NumPy.

For more information, consult the documentation of tidynamics at
http://lab.pdebuyl.be/tidynamics/

"""

import argparse
import numpy as np
import tidynamics


parser = argparse.ArgumentParser(description=__doc__,
                        formatter_class=argparse.RawDescriptionHelpFormatter)
parser.add_argument('action',
                    help='Choice of computation to perform on input file',
                    choices=['acf', 'msd'])
parser.add_argument('input_file',
                    help='Filename for input data')
parser.add_argument('output_file',
                    help='Filename for the result of the computation')
args = parser.parse_args()

input_data = np.loadtxt(args.input_file)

if args.action == 'acf':
    result = tidynamics.acf(input_data)
elif args.action == 'msd':
    result = tidynamics.msd(input_data)

np.savetxt(args.output_file, result)