average_ns

average_ns(fs, area, increment)

Computes the meridional average for each field in fs for a set of longitude strips.

Parameters

  • fs (Fieldset) – input fieldset

  • area (list) – area as [N,W,S,E] to perform the averaging

  • increment (number) – increment in degrees defining the size of the longitude strips

Return type

1d-ndarray or 2d-ndarray

The averaging is performed for each field individually within the longitude strips defined by area and increment. Each grid point value is weighted by the cosine of its latitude. Missing values are ignored. If a longitude strip contains no grid point values Nan is returned for that strip.

Example
ave = mv.average_ns(fs, [30,0,-30,360], 5)

Here we compute the averages over longitude strips bounded by 30N and 30S, in 5 degree intervals around the globe. The result for each field in fs is vector of 73 values (in this case values for 0 and 360 are duplicated values). Each value returned (representing the average at longitude Lon) is the average of non-missing values in those grid points whose longitude coordinate is between Lon-2.5 and Lon+2.5 (2.5 is 5/2), in the strip between 30N and 30S.