Center Finite Difference Gradient for a vector or a matrix
The script have the cyclic boundary in consideration, which is often encountered in global analysis of field in earth science.
Sen ZHAO (2020). center_finite_diff.m (https://www.mathworks.com/matlabcentral/fileexchange/46753-center_finite_diff-m), MATLAB Central File Exchange. Retrieved .
add test of zonal wind
Inspired by: circular diff