Energy in a Solenoid

%% Energy in a Solenoid
% Determines the energy stored in a solenoid

% Constants
muNaught = (4*pi)*10^-7;                   %[T*m/A] Vacuum Permeability

% Inputs and Variables
N = input('How many turns\n');
r = input('The radius\n');
l = input('The length\n');
I = input('The current of the system\n');

% Outputs and Equations
A = pi*r*r;
L = muNaught*A*N*N/l;
Energy = 0.5*L*I^2;
fprintf('The energy stored is %e J', Energy)