Changelog

dev

Added

• Classes subclassed from SimulationComponent now have a is_randomized class attribute that informs the Simulator of whether it should provide a BitGenerator to the class when simulating the component. - Classes which use a random component should now have a rng attribute,

  which should be treated in the same manner as other model parameters. In other words, random states are now effectively treated as model parameters.

• New simulator class FFTVis that uses the fftvis package to simulate visibilities. This is a CPU-based visibility simulator that is faster than MatVis for large, compact arrays.

Changed

• All random number generation now uses the new numpy API. - Rather than seed the global random state, a new BitGenerator is made

  with whatever random seed is desired.

  • The Simulator API has remained virtually unchanged, but the internal logic that handles random state management has received a significant update.

Deprecated

• Support for Python 3.9 has been dropped.

Fixed

• API calls for pyuvdata v2.4.0.

v4.1.0 [2023.06.26]

This release heavily focuses on performance of the visibility simulators, and in particular the VisCPU simulator.

Fixed

• Passing spline_interp_opts now correctly pipes these options through to the visibility simulators.

Added

• New _blt_order_kws class-attribute for VisibilitySimulator subclasses, that can be used to create the mock metadata in an order corresponding to that required by the simulator (instead of re-ordering after data creation, which can take some time).

• New optional compress_data_model() method on VisibilitySimulator subclasses that allows unnecessary metadata in the UVData object to be dropped before simulation (can be restored afterwards with the associated restore_data_model()). This can reduce peak memory usage.

• New check_antenna_conjugation parameter for the VisCPU simulator, to allow turning off checks for antenna conjugation, which takes time and is unnecessary for mock datasets.

• Dependency on hera-cli-utils which adds options like --log-level and --profile to hera-sim-vis.py.

• Option to use a taper in generating a bandpass.

• utils.tanh_window function for generating a two-sided tanh window.

• interpolators.Reflection class for building a complex reflection coefficient interpolator from a npz archive.

• Reflection coefficient and beam integral npz archives for the phase 1 and phase 4 systems (i.e., dipole feed and Vivaldi feed).

Changed

• run_check_acceptability is now False by default when constructing simulations from obsparams configuration files, to improve performance.

• For VisCPU simulator, we no longer copy the whole data array when simulating, but instead just fill the existing one, to save on peak RAM.

• Made VisCPU._reorder_vis() much faster (like 99% time reduction).

• The --compress option to hera-sim-vis.py is no longer a boolean flag but takes a file argument. This file will be written as a cache of the baseline-time indices required to keep when compressing by redundancy.

v4.0.0 [2023.05.22]

Breaking Changes

• Removed the HealVis wrapper. Use pyuvsim instead.

Changed

• Updated package to always use future array shapes for pyuvdata objects (this includes updates to PolyBeam and Simulator objects amongst others).

v3.1.1 [2023.02.23]

Changed

• Coupling matrix calculation in MutualCoupling has been updated to correctly calculate the coupling coefficients from the provided E-field beam.

v3.1.0 [2023.01.17]

Added

• MutualCoupling class that simulates the systematic described in Josaitis et al. 2021.

• New class attributes for the SimulationComponent class:

  • return_type specifies what type of return value to expect;

  • attrs_to_pull specifies which Simulator attributes to use.

• Some helper functions for MutualCoupling matrix multiplications.

• More attributes from the underlying UVData object exposed to the Simulator.

Changed

• Simulator._update_args logic has been improved.

• Simulator attributes lsts, times, and freqs are no longer cached.

v3.0.0

Removed

• Finally removed ability to set use_pixel_beams and bm_pix on the VisCPU simulator. This was removed in v1.0.0 of vis_cpu.

• Official support for py37.

Internals

• Added isort and pyupgrade pre-commit hooks for cleaner code.

v2.3.4 [2022.06.08]

Added

• NotImplementedError raised when trying to simulate noise using an interpolated sky temperature and phase-wrapped LSTs.

• More comparison tests of pyuvsim wrapper.

Fixed

• Inferred integration time in ThermalNoise when phase-wrapped LSTs are used.

• Added **kwargs to PolyBeam.interp method to match UVBeam.

• healvis wrapper properly sets cross-pol visibilities to zero.

Changed

• Temporarily forced all UVData objects in the code to use current array shapes.

v2.3.3 [2022.02.21]

Added

• adjustment.interpolate_to_reference now supports interpolating in time when there is a phase wrap in LST.

Changed

• Some logical statements in adjustment.interpolate_to_reference were changed to use binary operators on logical arrays instead of e.g. np.logical_or.

v2.3.2 [2022.02.18]

Added

• _extract_kwargs attribute added to the SimulationComponent class. This attribute is used by the Simulator to determine which optional parameters should actually be extracted from the data.

• antpair optional parameter added to the ThermalNoise class. This is used to determine whether to simulate noise via the radiometer equation (as is appropriate for a cross-correlation) or to just add a bias from the receiver temperature (which is our proxy for what should happen to an auto-correlation).

Fixed

• The Simulator class now correctly uses the auto-correlations to simulate noise for the cross-correlations.

v2.3.1 [2022.01.19]

Fixed

• Using the normalize_beams option is now possible with the from_config class method.

v2.3.0 [2022.01.19]

Added

• normalize_beams option in ModelData class. Setting this parameter to True enforces peak-normalization on all of the beams used in the simulation. The default behavior is to not peak-normalize the beams.

v2.2.1 [2022.01.14]

Added

• OverAirCrossCoupling now has a parameter amp_norm. This lets the user decide at what distance from the receiverator the gain of the emitted signal is equal to the base amplitude.

Fixed

• OverAirCrossCoupling now only simulates the systematic for cross-correlations.

• ReflectionSpectrum class had its is_multiplicative attribute set to True.

v2.2.0 [2022.01.13]

Added

• New ReflectionSpectrum class to generate multiple reflections over a specified range of delays/amplitudes.

Fixed

• Corrected some parameter initializations in sigchain module.

v2.1.0 [2022.01.12]

Added

• New OverAirCrossCoupling class to better model crosstalk in H1C data.

Changed

• Slightly modified Simulator logic for automatically choosing parameter values. This extends the number of cases the class can handle, but will be changed in a future update.

v2.0.0 [2021.11.16]

Added

• New VisibilitySimulator interface. See the `<https://hera-sim.readthedocs.io/en/latest/tutorials/visibility_simulator.html> Visibility Simulator Tutorial`_ for details. This is a breaking change for usage of the visibility simulators, and includes more robust handling of polarization, fixed ordering of data when put back into the UVData objects, more native support for using pyradiosky to define the sky model, and improved support for vis_cpu.

• Interface directly to the pyuvsim simulation engine.

• Ability to load tutorial data from the installed package.

• New and refactored tests for visibility simulations.

Fixed

• default feed_array for PolyBeam fixed.

Changed

• Updated tutorial for the visibility simulator interface (see above link).

• vis_cpu made an optional extra

• removed the conversions module, which is now in the vis_cpu package.

• Can now properly use pyuvdata>=2.2.0.

v1.1.1 [2021.08.21]

Added

• Add a Zernike polynomial beam model.

v1.1.0 [2021.08.04]

Added

• Enable polarization support for vis_cpu (handles polarized primary beams, but only Stokes I sky model so far)

• Add a polarized version of the analytic PolyBeam model.

v1.0.2 [2021.07.01]

Fixed

• Bug in retrieval of unique LSTs by Simulator when a blt-order other than time-baseline is used has been fixed. LSTs should now be correctly retrieved.

• empty_uvdata() now sets the phase_type attribute to “drift”.

v1.0.1 [2021.06.30]

Added

Fixed

• Discrepancy in PointSourceForeground documentation and actual implementation has been resolved. Simulated foregrounds now look reasonable.

Changed

• The time parameters used for generating an example Simulator instance in the tutorial have been updated to match their description.

• Simulator tutorial has been changed slightly to account for the foreground fix.

v1.0.0 [2021.06.16]

Added

• adjustment module from HERA Phase 1 Validation work

  • adjust_to_reference()

    • High-level interface for making one set of data comply with another set of data. This may involve rephasing or interpolating in time and/or interpolating in frequency. In the case of a mismatch between the two array layouts, this algorithm will select a subset of antennas to provide the greatest number of unique baselines that remain in the downselected array.

  • All other functions in this module exist only to modularize the above function.

• cli_utils module providing utility functions for the CLI simulation script.

• components module providing an abstract base class for simulation components.

  • Any new simulation components should be subclassed from the SimulationComponent ABC. New simulation components subclassed appropriately are automatically discoverable by the Simulator class. A MWE for subclassing new components is as follows:

    @component
    class Component:
        pass
    
    class Model(Component):
        ...
    

    The Component base class tracks any models subclassed from it and makes it discoverable to the Simulator.

• New “season” configuration (called "debug"), intended to be used for debugging the Simulator when making changes that might not be easily tested.

• chunk_sim_and_save() function from HERA Phase 1 Validation work

  • This function allows the user to write a pyuvdata.UVData object to disk in chunks of some set number of integrations per file (either specified directly, or specified implicitly by providing a list of reference files). This is very useful for taking a large simulation and writing it to disk in a way that mimics how the correlator writes files to disk.

• Ability to generate noise visibilities based on autocorrelations from the data. This is achieved by providing a value for the autovis parameter in the thermal_noise function (see ThermalNoise).

• The vary_gains_in_time() provides an interface for taking a gain spectrum and applying time variation (linear, sinusoidal, or noiselike) to any of the reflection coefficient parameters (amplitude, phase, or delay).

• The CrossCouplingSpectrum provides an interface for generating multiple realizations of the cross-coupling systematic spaced logarithmically in amplitude and linearly in delay. This is ported over from the Validation work.

Fixed

• The reionization signal produced by eor.noiselike_eor is now guaranteed to be real-valued for autocorrelations (although the statistics of the EoR signal for the autocorrelations still need to be investigated for correctness).

Changed

• API BREAKING CHANGES

  • All functions that take frequencies and LSTs as arguments have had their signatures changed to func(lsts, freqs, *args, **kwargs).

  • Functions that employ rough_fringe_filter() or rough_delay_filter() as part of the visibility calculation now have parameters delay_filter_kwargs and/or fringe_filter_kwargs, which are dictionaries that are ultimately passed to the filtering functions. foregrounds.diffuse_foreground and eor.noiselike_eor are both affected by this.

  • Some parameters have been renamed to enable simpler handling of package-wide defaults. Parameters that have been changed are:

    • filter_type -> delay_filter_type in gen_delay_filter()

    • filter_type -> fringe_filter_type in gen_fringe_filter()

    • chance -> impulse_chance in rfi_impulse (see Impulse)

    • strength -> impulse_strength in rfi_impulse (see Impulse)

    • Similar changes were made in rfi_dtv (DTV) and rfi_scatter (Scatter).

  • Any occurrence of the parameter fqs has been replaced with freqs.

  • The noise.jy2T function was moved to utils and renamed. See jansky_to_kelvin().

  • The parameter fq0 has been renamed to f0 in RfiStation.

  • The _listify function has been moved from rfi to utils.

  • sigchain.HERA_NRAO_BANDPASS no longer exists in the code, but may be loaded from the file HERA_H1C_BANDPASS.npy in the data directory.

• Other Changes

  • The Simulator has undergone many changes that make the class much easier to use, while also providing a handful of extra features. The new Simulator provides the following features:

    • A universal add() method for applying any of the effects implemented in hera_sim, as well as any custom effects defined by the user.

    • A get() method that retrieves any previously simulated effect.

    • The option to apply a simulated effect to only a subset of antennas, baselines, and/or polarizations, accessed through using the vis_filter parameter.

    • Multiple modes of seeding the random state to achieve a higher degree of realism than previously available.

    • The calculate_filters() method pre-calculates the fringe-rate and delay filters for the entire array and caches the result. This provides a marginal-to-modest speedup for small arrays, but can provide a significant speedup for very large arrays. Benchmarking results TBD.

    • An instance of the Simulator may be generated with an empty call to the class if any of the season defaults are active (or if the user has provided some other sufficiently complete set of default settings).

    • Some of the methods for interacting with the underlying pyuvdata.UVData object have been exposed to the Simulator (e.g. get_data).

    • An easy reference to the chunk_sim_and_save() function.

  • foregrounds, eor, noise, rfi, antpos, and sigchain have been modified to implement the features using callable classes. The old functions still exist for backwards-compatibility, but moving forward any additions to visibility or systematics simulators should be implemented using callable classes and be appropriately subclassed from SimulationComponent.

  • empty_uvdata() has had almost all of its parameter values set to default as None. Additionally, the n_freq, n_times, antennas parameters are being deprecated and will be removed in a future release.

  • white_noise() is being deprecated. This function has been moved to the utility module and can be found at gen_white_noise().

v0.4.0 [2021.05.01]

Added

• New features added to vis_cpu

  • Analytic beam interpolation

    • Instead of gridding the beam and interpolating the grid using splines, the beam can be interpolated directly by calling its interp method.

    • The user specifies this by passing use_pixel_beams=False to vis_cpu.

  • A simple MPI parallelization scheme

    • Simulation scripts may be run using mpirun/mpiexec

    • The user imports mpi4py into their script and passes mpi_comm=MPI.COMM_WORLD to vis_cpu

  • New PolyBeam and PerturbedPolyBeam analytic beams (classes)

    • Derived from pyuvsim.Analytic beam

    • Based on axisymmetric Chebyshev polynomial fits to the Fagnoni beam.

    • PerturbedPolyBeam is capable of expressing a range of non-redundancy effects, including per-beam stretch factors, perturbed sidelobes, and ellipticity/rotation.

v0.3.0 [2019.12.10]

Added

• New sub-package simulators

  • VisibilitySimulators class

    • Provides a common interface to interferometric visibility simulators. Users instantiate one of its subclasses and provide input antenna and sky scenarios.

    • HealVis subclass

    • Provides an interface to the healvis visibility simulator.

  • VisCPU subclass

    • Provides an interface to the viscpu visibility simulator.

  • conversions module

    • Not intended to be interfaced with by the end user; it provides useful coordinate transformations for VisibilitySimulators.

v0.2.0 [2019.11.20]

Added

• Command-line Interface

  • Use anywhere with hera_sim run [options] INPUT

  • Tutorial available on readthedocs

• Enhancement of run_sim method of Simulator class

  • Allows for each simulation component to be returned

    • Components returned as a list of 2-tuples (model_name, visibility)

    • Components returned by specifying ret_vis=True in their kwargs

• Option to seed random number generators for various methods

  • Available via the Simulator.add_ methods by specifying the kwarg seed_redundantly=True

  • Seeds are stored in Simulator object, and may be saved as a npy file when using the Simulator.write_data method

• New YAML tag !antpos

  • Allows for antenna layouts to be constructed using hera_sim.antpos functions by specifying parameters in config file

Fixed

• Changelog formatting for v0.1.0 entry

Changed

• Implementation of defaults module

  • Allows for semantic organization of config files

  • Parameters that have the same name take on the same value

    • e.g. std in various rfi functions only has one value, even if it’s specified multiple times

v0.1.0 [2019.08.28]

Added

• New module interpolators

  • Classes intended to be interfaced with by end-users:

    • Tsky

      • Provides an interface for generating a sky temperature interpolation object when provided with a .npz file and interpolation kwargs.

    • Beam, Bandpass

      • Provides an interface for generating either a poly1d or interp1d interpolation object when provided with an appropriate datafile.

• New module defaults

  • Provides an interface which allows the user to dynamically adjust default parameter settings for various hera_sim functions.

• New module __yaml_constructors

  • Not intended to be interfaced with by the end user; this module just provides a location for defining new YAML tags to be used in conjunction with the defaults module features and the Simulator.run_sim method.

• New directory config

  • Provides a location to store configuration files.

Fixed

Changed

• HERA-specific variables had their definitions removed from the codebase. Objects storing these variables still exist in the codebase, but their definitions now come from loading in data stored in various new files added to the data directory.

v0.0.1

• Initial released version