swh:1:snp:da9f681de57b9112454de79fd861fda29a83f001
Tip revision: 617c8e77d30037c1e1fb3a2ab460cb0aaa11eca1 authored by Paul La Plante on 29 June 2019, 20:31:12 UTC
Add support for bitshuffle on visdata
Add support for bitshuffle on visdata
Tip revision: 617c8e7
uvfits_memtest.py
#!/usr/bin/env python2.7
# -*- mode: python; coding: utf-8 -*
# Copyright (c) 2018 Radio Astronomy Software Group
# Licensed under the 2-clause BSD License
from __future__ import absolute_import, division, print_function
from memory_profiler import profile
import numpy as np
from astropy import constants as const
from astropy.io import fits
from pyuvdata import UVData
@profile
def read_uvfits():
filename = '/Volumes/Data1/mwa_uvfits/1066571272.uvfits'
# first test uvdata.read_uvfits. First read metadata then full data
uv_obj = UVData()
uv_obj.read_uvfits(filename, read_data=False, read_metadata=False)
uv_obj.read_uvfits_metadata(filename)
uv_obj.read_uvfits_data(filename)
del(uv_obj)
# now test uvdata.read_uvfits with select on read.
uv_obj = UVData()
uv_obj.read_uvfits(filename, read_data=False, read_metadata=False)
uv_obj.read_uvfits_metadata(filename)
uv_obj.read_uvfits_data(filename, freq_chans=np.arange(196))
del(uv_obj)
# now test details with astropy
hdu_list = fits.open(filename, memmap=True)
vis_hdu = hdu_list[0]
# only read in times, then uvws, then visibilities
time0_array = vis_hdu.data.par('date')
uvw_array = (np.array(np.stack((vis_hdu.data.par('UU'),
vis_hdu.data.par('VV'),
vis_hdu.data.par('WW')))) * const.c.to('m/s').value).T
if vis_hdu.header['NAXIS'] == 7:
data_array = (vis_hdu.data.data[:, 0, 0, :, :, :, 0]
+ 1j * vis_hdu.data.data[:, 0, 0, :, :, :, 1])
else:
data_array = (vis_hdu.data.data[:, 0, 0, :, :, 0]
+ 1j * vis_hdu.data.data[:, 0, 0, :, :, 1])
data_array = data_array[:, np.newaxis, :, :]
# test for releasing resources
del(time0_array)
del(uvw_array)
del(data_array)
# release file handles
del(vis_hdu)
del(hdu_list)
# now test reading a slice of the data
hdu_list = fits.open(filename, memmap=True)
vis_hdu = hdu_list[0]
Nfreqs = vis_hdu.header['NAXIS4']
freq_index = int(Nfreqs // 2)
if vis_hdu.header['NAXIS'] == 7:
data_slice = (vis_hdu.data.data[:, 0, 0, :, 0:freq_index, :, 0]
+ 1j * vis_hdu.data.data[:, 0, 0, :, 0:freq_index, :, 1])
else:
data_slice = (vis_hdu.data.data[:, 0, 0, 0:freq_index, :, 0]
+ 1j * vis_hdu.data.data[:, 0, 0, 0:freq_index, :, 1])
data_slice = data_slice[:, np.newaxis, :, :]
del(data_slice)
del(vis_hdu)
del(hdu_list)
del(filename)
return
if __name__ == '__main__':
read_uvfits()