NAtoLD( Normal, Axial, alpha)

This function converts normal/axial forces to lift/drag given angle of attack.

function [ Lift,Drag ] = NAtoLD( Normal, Axial, alpha)
% This function converts normal/axial forces to lift/drag.
%% OR vice versa !!! $$ Angle of attack 'alpha' is needed as well $$
%Input: Normal = Normal Force [N], Axial = Axial Force [N], alpha [deg]
% OR input --> Lift, Drag, alpha [optional]
%Output: Lift [N], Drag [N] OR Normal [N], Axial [N]

%% Argument management:
% arg3 is optional,
% arg1 & arg2 are mandatory
if nargin < 3
alpha = zeros(length(Normal),1); %[m] Default alpha is zero.
end