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 thatmkdocstrings
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 welldefined 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
Source code in ocelot/calculate/position.py
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