__main__.py

'''PyFragment dispatcher: launch a calculation from command-line.

This file allows the pyfrag package to be invoked from the terminal:
 >>> python pyfrag input_file

To function correctly, the directory containing pyfrag should be in PYTHONPATH.

It invokes the input file parser, creates scratch directories, and launches
the requested PyFrag module's kernel() function.
'''
import argparse
import time

from pyfrag.Globals import params, MPI, logger
from pyfrag.Globals import utility as util

import pyfrag.backend
import pyfrag.bim
import pyfrag.vbct
import pyfrag.drivers

def get_driver_module(taskname):
    return {
            'bim_e': pyfrag.bim.bim,
            'bim_grad' : pyfrag.bim.bim,
            'bim_numgrad' : pyfrag.drivers.bim_numgrad,
            'bim_hess' : pyfrag.bim.bim,
            'vbct_e' : pyfrag.vbct.energy,
            'bim_opt' : pyfrag.drivers.bim_opt,
            'bim_cellopt' : pyfrag.drivers.bim_cellopt,
            'bim_md' : pyfrag.drivers.bim_md
            }.get(taskname)

# PARSE COMMAND LINE ARGUMENTS
# ----------------------------
parser = argparse.ArgumentParser(description="Launch fragment calculation "
                                 "with PyFragment")

parser.add_argument("input_file", help="input file to PyFragment")


group = parser.add_mutually_exclusive_group()
group.add_argument("-v", "--verbose", action="store_true",
                    help="make drivers print extra debug info")
group.add_argument("-q", "--quiet", action="store_true",
                    help="make drivers silent (only final result printed)")

parser.add_argument("--qm_logfile", type=str,
                    help="log QM calc input/output to file "
                    "for heavy debugging")
args = parser.parse_args()

# PARSE INPUT FILE
# ----------------
util.parse_input(args.input_file)
params.verbose = args.verbose
params.quiet = args.quiet
params.qm_logfile = args.qm_logfile
params.args = args

# MAKE SCRATCH DIRS
# -----------------
if 'scrdir' in params.options:
    scratch_top = params.options['scrdir']
else:
    scratch_top = None
util.make_scratch_dirs(scratch_top)

# DISPATCH DRIVER, PRINT RESULTS
# -----------------------------
try:
    task_module = get_driver_module(params.options['task'])
    t_start = time.time()
    results = task_module.kernel()
    t_end = time.time()
    if MPI.rank == 0:
        seconds = t_end - t_start
        print "Task %s done in %s\n" % (params.options['task'], util.pretty_time(seconds))
        print_results = getattr(logger, 'print_%s_results' % params.options['task'])
        print_results(results)
finally:
    util.clean_scratch_dirs()