Work in Progress

The full API of ocelot is likely to change a lot before its first proper release. This API page for ocelot.calculate is just a demo to help us make sure that mkdocstrings is working.

ocelot.calculate.position.mean_position(longitudes, latitudes, degrees=True)

Calculates the spherical mean of angular positions, specified as longitudes and latitudes. This uses directional statistics to do so in a way that is aware of discontinuities, such as the fact that 0° = 360°.

Parameters:

Name	Type	Description	Default
longitudes	array - like	Array of longitudinal positions of stars in your cluster (e.g. right ascensions or galactic longitudes.) Assumed to be in the range [0°, 360°].	required
latitudes	array - like	Array of latitudinal positions of stars in your cluster (e.g. declinations or galactic latitudes.) Assumed to be in the range [-90°, 90°].	required
degrees	bool	Whether longitudes and latitudes are in degrees, and whether to return an answer in degrees. Defaults to True. If False, longitudes and latitudes are assumed to be in radians, with ranges [0, 2π] and [-π/2, π/2] respectively.	True

Returns:

Name	Type	Description
mean_longitude	float
mean_latitude	float

Notes

This function explicitly assumes that your star cluster has a well-defined mean position. Some configurations (such as points uniformly distributed in at least one axis of a sphere) will not have a meaningful mean position.

Internally, this function uses scipy.stats.directional_stats, with a definition taken from [1]. See [2] for more background.

References

[1] Mardia, Jupp. (2000). Directional Statistics (p. 163). Wiley. [2] https://en.wikipedia.org/wiki/Directional_statistics