How to take gradient, curl or divergence of numeric vector fields?

I have electric field vectors from FDTD simulations at different sets of (x,y) points. The E fields have numerical values at different (x,y) because I have extracted the data from simulation results. For example, the E fields are (751*751) dimensional matrices in Matlab. How can I calculate curl of E or divergence of E in this case? I mean, if my E fields were just analytical functions of x and y, I could use the in built curl or divergence command of Matlab. But in this case the fields have numerical values at different x,y points. Any help or suggestion will be greatly appreciated.

Answer 1

[Daniel M]

You can use the curl and divergence functions which are not in the symbolic toolbox:

<https://www.mathworks.com/help/matlab/ref/curl.html>

<https://www.mathworks.com/help/matlab/ref/divergence.html>