galpy.df.streamdf.sigangledAngle

streamdf.sigangledAngle(dangle, assumeZeroMean=True, smallest=False, simple=False)[source]

Calculate the dispersion in the perpendicular angle at a given angle.

Parameters:

  • dangle (float) – Angle offset along the stream.

  • assumeZeroMean (bool, optional) – If True, assume that the mean is zero (should be). Default is True.

  • smallest (bool, optional) – Calculate for smallest eigenvalue direction rather than for middle. Default is False.

  • simple (bool, optional) – If True, return an even simpler estimate. Default is False.

Returns:

Dispersion in the perpendicular angle at this angle.

Return type:

float or Quantity

Notes

  • 2013-12-06 - Written - Bovy (IAS)