#!/usr/bin/env python
"""
killMS, a package for calibration in radio interferometry.
Copyright (C) 2013-2017  Cyril Tasse, l'Observatoire de Paris,
SKA South Africa, Rhodes University

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
"""
from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import numpy as np

def IsChanEquidistant(ChanFreq):

    if ChanFreq.size>1:
        df=ChanFreq.flatten()[1::]-ChanFreq.flatten()[0:-1]
        ddf=np.abs(df-np.mean(df))
        ChanEquidistant=int(np.max(ddf)<1.)
    else:
        ChanEquidistant=0
    return ChanEquidistant
