curl(X,Y,U,V) in Matlab will give you the angular velocity or vorticity of a 2D vector field (U,V) with a 3-point stencil. This implementation will compute the curl of a **UNIFORM*** grid with a 'npts' point stencil (only supports central differences). Since it uses convolution to accomplish that, the corners and edges of the grid will be incorrect.
Using for PIV post-processing, where noise can be an issue when computing derivatives.
Shoutout to Greg von Winckel for providing the stencil generator code (https://www.mathworks.com/matlabcentral/fileexchange/5269-finite-difference-weights)!
Fernando Zigunov (2019). 2D Vorticity with any stencil (https://www.mathworks.com/matlabcentral/fileexchange/71612-2d-vorticity-with-any-stencil), MATLAB Central File Exchange. Retrieved .