Visibilities

class xrayvision.visibility.Visibilities(visibilities, u, v, phase_center=<Quantity [0., 0.] arcsec>, meta=None, uncertainty=None, amplitude=None, amplitude_uncertainty=None, phase=None, phase_uncertainty=None)

Bases: VisibilitiesABC

A class for holding visibilities.

Parameters:

• visibilities (Quantity) – Array of N complex visibilities at coordinates in uv.

• u (Annotated[Quantity, Unit("1 / deg")]) – Array of u coordinates where visibilities will be evaluated.

• v (Annotated[Quantity, Unit("1 / deg")]) – Array of v coordinates where visibilities will be evaluated.

• phase_center (astropy.units.Quantity with angular unit.) – The location of the phase center of the visibilities. Default = [0, 0] arcsec

• meta (VisMetaABC | None) – Metadata associated with the visibilities. In order to use this Visibilities object to make a Map, meta must contain a key 'observer_coordinate' which gives a SkyCoord, designating the location from which the visibilities were measured. To give each visibility a label, include a key, 'vis_labels', giving an iterable of the same length as the number of visibilities.

• uncertainty (Quantity | None) – The uncertainty of the visibilities. Must be same shape and unit as visibilities.

• amplitude (Quantity | None) – The amplitude of the visibilities. If not given, amplitudes be calculated directly from the visibilities. Must be same shape and unit as visibilities.

• amplitude_uncertainty (Quantity | None) – The uncertainty of the visibility amplitudes. If not provided, amplitude uncertainties will be calculated from visibilities, visibility uncertainties, and amplitudes. Must be same shape and unit as visibilities.

• phase (Annotated[Quantity, Unit("deg")] | None) – The phase of the visibilities. If not given, phases will be calculated directly from the visibilities. Must be same shape as visibilities.

• phase_uncertainty (Annotated[Quantity, Unit("deg")] | None) – The uncertainty of the visibility phases. If not provided, phase uncertainties will be calculated from visibilities, visibility uncertainties, and amplitudes. Must be same shape and unit as visibilities.

Attributes Summary

amplitude	Amplitudes of the visibilities.
amplitude_uncertainty	Amplitude uncertainty of the visibilities.
meta	Metadata.
phase	Phases of the visibilities.
phase_center	The position of the phase center of the visibilities.
phase_uncertainty	Phase uncertainty of the visibilities.
u	u-coordinate on the complex plane of the visibilities.
uncertainty	Uncertainties on visibilities values.
v	v-coordinate on the complex plane of the visibilities.
visibilities	Complex numbers representing the visibilities.

Methods Summary

index_by_label(*labels)

Extract visibilities based on their labels.

Attributes Documentation

amplitude

amplitude_uncertainty

meta

phase

phase_center

phase_uncertainty

u

uncertainty

v

visibilities

Methods Documentation

index_by_label(*labels)

Extract visibilities based on their labels.

Parameters:

labels (Any) – The labels of the desired visibilities.

Returns:

new_vis

Return type:

Same as self type