Re_func(V_inf, altitude, l)

Calc Reynold's # given altitude, velocity, and length

function [ Re ] = Re_func(V_inf, altitude, l)
%This function outputs the Reynolds number for dry air given an altitude [m],
%free stream velocity [ m/s], and characteristic length [ m]. Often the characteristic
%length for airfoils is the chord length.
%Inputs = altitude [m], V_inf = free stream velocity [m/s], l = characteristic length [m]
%Outputs = Reynolds numbers [ dimensionless ]
% arg2 and arg3 are optional,
% arg1 is mandatory

%You can call this function by either somefcn(arg1),somefcn(arg1,arg2) or somefcn(arg1,arg2,arg3), but not somefcn(ar1,arg3).