MATLAB friction factor iterator

iterator.m

Re_guess = 2e4;

r = 0.002; % roughness
R = 0.075; % pipe radius
D = 2*R;
p = 1000; % density
visc = 1.141e-3; % viscosity

latest_q = q_from_f(f_guess, R)
penultimate_q = 1;

Re = Re_guess;
f = Moody(Re_guess, r);

tolerance = 0.001;

while (penultimate_q - latest_q)/penultimate_q > tolerance
    Re = (4*latest_q*p) / (pi*visc*D);
    f = Moody(Re, r);
    
    penultimate_q = latest_q;
    latest_q = q_from_f(f, R)
end