poisson_sym(V,X,coo​rdinate_system)

This Function calculate the double derivative (Poisson's Equation) of 3D symbolic vector field

This Function calculates the double derivative (Poisson's Equation) of the 3D symbolic vector in Cartesian, Cylindrical, and Spherical coordinate system.
function poissonSym = poisson_sym(V,X,coordinate_system)
V is the 3D symbolic vector field
X is the parameter which the divergence will calculate with respect to.
coordinate_system is the kind of coordinate system at which the vector field is specified.
The Poisson's Equation is calculated according to (Engineering Electromagnetics Sixth Edition William H. Hayt, Jr. . John A. Buck)
Example (1):
V=4*y*z/(x^2+1)
Del_2_V=poisson_sym(V,[x y z],'Cartesian')
Example (2):
V=5*rho^2*cos(2*phi)
Del_2_V=poisson_sym(V,[rho phi z],'Cylindrical')
Example (3):
V=2*cos(phi)/r^2;
Del_2_V=poisson_sym(V,[r theta phi],'Spherical')