average_ew
- average_ew(fs, area, increment)
Computes the zonal average for each field in
fs
for a set of latitude belts.- Parameters
fs (
Fieldset
) – input fieldsetarea (list) – area as [N,W,S,E] to perform the averaging
increment (number) – increment in degrees defining the size of the latitude belts
- Return type
1d-ndarray or 2d-ndarray
If
fs
only contains one field a 1d-ndarray is returned otherwise the result is a 2d-ndarray.The averaging is performed for each field individually within the latitude belts defined by
area
andincrement
. Each grid point value is weighted by the cosine of its latitude. Missing values are ignored. If a latitude belt contains no grid point values Nan is returned for that belt.- Example
ave = mv.average_ew(fs, [60,-180,-60,180], 2.5)
Here we compute the averages over full latitude circles starting from 60N, stepping by 2.5 degrees until 60S. If
fs
contains only one field the output will be a 1d-ndarray of 49 E-W average values, from North to South. Iffs
contains n fields then the output will be an array of n 1d-arrays each containing 49 values. Each value in the result represents the average at latitude Lat based on those grid points whose latitude coordinate is between Lat-1.25 and Lat+1.25 (1.25 is 2.5/2), i.e. within a latitude belt with width of 2.5 degrees, centered around Lat.
Note
See also
average_ns()
.