#!/usr/bin/env python
# XDS_ASCII.py
# Maintained by G.Winter
#
#   Copyright (C) 2008 CCLRC, Graeme Winter
#
#   This code is distributed under the BSD license, a copy of which is
#   included in the root directory of this package.
#
# 22nd February 2008
#
# Code for manipulating XDS_ASCII files from XDS CORRECT.
#

import os

def remove_misfits(xdsin, xdsout):
    '''Read through the XDS_ASCII input file and remove the misfit
    reflections (SD < 0.0) - write out the remains to xdsout.'''

    if xdsin == xdsout:
        raise RuntimeError, 'xdsin and xdsout same file'

    if not os.path.exists(xdsin):
        raise RuntimeError, 'xdsin does not exist'

    fout = open(xdsout, 'w')

    ignored = 0

    for record in open(xdsin, 'r').readlines():

        if not record.strip():
            continue

        if record[0] == '!':
            fout.write(record)
            continue

        values = map(float, record.split())

        if values[4] > 0.0:
            fout.write(record)
            continue
        else:
            ignored += 1

    fout.close()

    return ignored