galpy.df.StreamTrack.phi1

StreamTrack.phi1(tp, **kwargs)[source]

Custom-frame longitude phi1 along the track.

Requires custom_sky_transform to have been set at construction.

Parameters:

  • tp (float, array, or Quantity) – Curve parameter(s); Quantity inputs are parsed per parameter_kind. Out-of-range entries return NaN.

  • ro (float or Quantity, optional) – Distance scale (kpc); overrides the stored value.

  • vo (float or Quantity, optional) – Velocity scale (km/s); overrides the stored value.

  • use_physical (bool, optional) – Override the object-wide physical-units default.

  • quantity (bool, optional) – Return an astropy Quantity if True.

Returns:

Custom-frame phi1 in degrees.

Return type:

float, numpy.ndarray, or Quantity