Graph of a 3D vector field and its divergence and curl

Visualize vector field quiver, divergence (slice), and curl (quiver) at given 3D coordinates

%% Divergence and Curl of Vector Function with 3 Independent Variables
% by Prof. Roche C. de Guzman

%% Given
f = @(x,y,z) [-2*y; x; z/10]; % anonymous fx: f(x,y)
xi = -2; xf = 2; yi = -1; yf = 1; zi = 0; zf = 3; n = 5; % independent variables: initial and final values, and number of elements