from v1.04 of interferometry:
============================

In interferometry.py,

(*) Removed the unused attribute sample_density from member function __init__()
of classes Interferometer and InterferometerArray
(*) Added two member functions generate_noise() and add_noise() which generate
and add noise to the sky visibilities under class InterferometerArray
(*) Removed the computation and addition of noise on visibilities in observe()
member function of class InterferometerArray and moved it to member functions
generate_noise() and add_noise() respectively
(*) Removed a factor 2 while estimating memory_required in member function
observe() of class InterferometerArray. This means size of vis_wts is ignored
since it anyway follows numpy array broadcasting rule
(*) Removed a factor 2 while estimating the downsize_factor if memory shortage
is detected in observe() member function of class InterferometerArray
(*) memory_required in member function observe() of class InterferometerArray is
now estimated from free+cached+buffer memory instead of only from free memory
(*) In member function delay_transform() of class InterferometerArray, changed
the delay transform to be IFFT instead of FFT to be consistent with the sign
convention used in creating the visibilities along frequency axis in member
function observe() and docstring changed accordingly
(*) In member function delay_transform() of class InterferometerArray, replaced
len(self.timestamp) with self.n_acc
(*) In member function save() of class InterferometerArray, now write another
extension to the FITS file containing Tsys information.
(*) In member function save() of class InterferometerArray, now write another
extension to the FITS file containing timestamp information. Timestamps are now
written as 12-character strings
(*) In member function save() of class InterferometerArray, changed the
formatting of writing the extension table containing labels. Labels are now
written as 5-character strings
(*) In member function __init__() of class InterferometerArray, made changes to
initialization from init_file so it is compatible with output of save() member
function.
(*) In member function __init__() of class InterferometerArray, made changes to
data type of attributes vis_freq, skyvis_freq, vis_noise_freq, skyvis_lag,
vis_lag, and vis_noise_lag so they can hold complex values
(*) In member function delay_transform() of class InterferometerArray, padding
with zeros reduced the amplitude and hence the amplitudes are now corrected
based on the padding factor
(*) Added attributes phase_center and phase_center_coords to class
InterferometerArray. These are updated accordingly in all the member functions
of this class. By default, these are made equal to the pointing center and
pointing coordinates.
(*) Added member function phase_centering() to rotate visibility phases to any
given phase center.
(*) Phase center information is now saved in save() member function and also
initialized in __init__() member function through init file in class
InterferometerArray. It is also concatenated in member function concatenate().
(*) In member function concatenate() of class InterferometerArray, added the
concatenation of attribute bp_wts which was missing earlier

In primary_beams.py,

(*) Renamed skyunits to skycoords in the dosctring of
isotropic_radiators_array_field_pattern()