%Trevor Tanner
%BIOEN 6002
%HW 1
%Problem 3

clc;
close all;
clear all;

k = 1.3806503E-23; %[m2 kg s-2 K-1] - Boltzmann constant
T = 273.15 + 37; %[K] - Body temperature
n = 1E-3; %Viscosity of Water [Pa*S]

syms D1 k1 T1 gam1 n1 r1 M1 expr1;

gam1 = solve('(k1*T1)/gam1=D1',gam1);
r1 = solve('gam1=6*pi*n1*r1',r1);

M = [18, 32, 180, 13680, 35000, 68000, 345000];
D = [21, 10, 7, 1, 0.8, 0.7, 0.07]*1E-6*(1/100^2);

r1 = subs(eval(r1),{k1,T1,n1,D1},{k,T,n,D})
rCm = r1*100
rPlot = rCm(1:7)
mPlot = M(1:7)

plot(M,rCm,'*');
[fitresult, gof] = createFit(mPlot,rPlot)
xlabel('Molecular Weight [g/mol]')
ylabel('Radius [cm]')