avgpbz.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
#
# Copyright (C) 2019 - Francesco de Gasperin
#
# 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

"""
Script to zero the corners of avgpb images
"""

import pyrap.images as pim
import argparse
import numpy as np

def main(args):

 image = args.image
 pb = pim.image(image)
 pbdata = pb.getdata()
 (nx,ny) = pbdata.shape[2:]
 pbrad = args.radius*nx
 cy = ny/2
 cx = nx/2
 pbcounter = 0
 for j in range(nx,cx,-1):
  k = ny
  while np.sqrt((j-cx)**2+(k-cy)**2)>pbrad and k>cy:
   pbcounter += 1
   pbdata[:,:,k-1,j-1]=0.
   pbdata[:,:,k-1,nx-j]=0.
   pbdata[:,:,ny-k,j-1]=0.
   pbdata[:,:,ny-k,nx-j]=0.
   k -= 1
  if k == ny:
   print(j,nx)
   break
 print(pbcounter,'x 4 =',pbcounter*4,'zeros replaced')
 if args.output == '':
  outim = image.rstrip('/')+'z'
 else:
  outim = args.output
 print('Writing',outim)
 pout = pim.image(outim,values=pbdata,coordsys=pb.coordinates())
 
print("AVGPB editor")
parser = argparse.ArgumentParser(description="Zero corners of avgpb images")
parser.add_argument('image',help="Image to adjust")
parser.add_argument('-o','--output',help="Output image name [default is to add a 'z' to the end of the input filename",default='')
parser.add_argument('-r','--radius',help='Radius beyond which to zero avgpb values (expressed as fraction of image width) [default 0.5 = half of image width, i.e. zero outside of a circle with diameter NAXIS1]',default=0.5,type=float)
args=parser.parse_args()
main(args)