matvis.wrapper.simulate_vis

matvis.wrapper.simulate_vis(ants, fluxes, ra, dec, freqs, lsts, beams, polarized=False, precision=1, latitude=-0.5361913261514378, use_feed='x', use_gpu: bool = False, beam_spline_opts: dict | None = None, beam_idx: ndarray | None = None, **backend_kwargs)[source]

Run a basic simulation using matvis.

This wrapper handles the necessary coordinate conversions etc.

Parameters:

  • ants (dict) – Dictionary of antenna positions. The keys are the antenna names (integers) and the values are the Cartesian x,y,z positions of the antennas (in meters) relative to the array center.

  • fluxes (array_like) – 2D array with the flux of each source as a function of frequency, of shape (NSRCS, NFREQS).

  • ra (array_like) – Arrays of source RA and Dec positions in radians. RA goes from [0, 2 pi] and Dec from [-pi, +pi].

  • dec (array_like) – Arrays of source RA and Dec positions in radians. RA goes from [0, 2 pi] and Dec from [-pi, +pi].

  • freqs (array_like) – Frequency channels for the simulation, in Hz.

  • lsts (array_like) – Local sidereal times for the simulation, in radians. Range is [0, 2 pi].

  • beams (list of UVBeam objects) – Beam objects to use for each antenna.

  • pixel_beams (bool, optional) – If True, interpolate the beams onto a pixel grid. Otherwise, use the UVBeam interpolation method directly.

  • beam_npix (int, optional) – If pixel_beam == True, sets the pixel grid resolution along each dimension (corresponds to the n_pix_lm parameter of the conversions.uvbeam_to_lm function).

  • polarized (bool, optional) – If True, use polarized beams and calculate all available linearly- polarized visibilities, e.g. V_nn, V_ne, V_en, V_ee. Default: False (only uses the ‘ee’ polarization).

  • precision (int, optional) – Which precision setting to use for matvis(). If set to 1, uses the (np.float32, np.complex64) dtypes. If set to 2, uses the (np.float64, np.complex128) dtypes.

  • latitude (float, optional) – The latitude of the center of the array, in radians. The default is the HERA latitude = -30.7215 * pi / 180.

  • beam_spline_opts (dict, optional) – Options to be passed to pyuvdata.uvbeam.UVBeam.interp() as spline_opts.

Returns:

vis – Complex array of shape (NFREQS, NTIMES, NFEED, NFEED, NANTS, NANTS) if polarized == True, or (NFREQS, NTIMES, NANTS, NANTS) otherwise.

Return type:

array_like