Utilities

Cythonised functions used by methods of octant.core.TrackRun.

octant.utils.great_circle()

Calculate great circle distance between two points on a sphere

Parameters

• lon1 (double) – Longitude of the first point

• lon2 (double) – Longitude of the second point

• lat1 (double) – Latitude of the first point

• lat2 (double) – Latitude of the second point

• r_planet (double, optional) – Radius of the planet in metres Default: EARTH_RADIUS

Returns

dist – Distance in metres

Return type

double

Examples

>>> great_circle(-180.0, -170.0, 30.0, 40.0)
1435334.9068947

octant.utils.mask_tracks()

Count how many points of a cyclone track should be masked by their proximity to masked values in a 2D array.

Parameters

• mask (double, shape(M, N)) – Mask array with 1 for masked values

• lon2d (double, shape(M, N)) – Array of longitudes corresponding to the mask

• lat2d (double, shape(M, N)) – Array of latitudes corresponding to the mask

• lonlat (double, shape(P, 2)) – Array of track’s longitudes and latitudes

• dist (double) – Distance in metres to check proximity

• r_planet (double, optional) – Radius of the planet in metres Default: EARTH_RADIUS

Returns

Return type

Fraction of masked points of the track