%c is the speed of sound in air at 20 Celsius
c = 343;

% r is the complex vector of reflection coefficient as a 
% function of om (omega, the frequency). There are 10 values 
% of om given below. We will be given you two new sets of data 
% corresponding to a hard wall and a soft foam
r=[-1.0346+0.1035i 
-0.7657+0.0766i 
-1.1495+0.1149i  
-1.0963+0.1096i
-1.0451+0.1045i
-0.8845+0.0885i 
-0.9891+0.0989i
-1.0755+0.1076i
-1.1225+0.1122i 
-0.8706+0.0871i];

om = [50,100,150,200,250,300,350,400,450,500]*2*pi;

options = foptions;
options(2) = 1e-14;
options(3) = 1e-14;
options(14) = 1000;

figure(1)
plot(om,real(r),'-*')
hold on
plot(om,imag(r),'-o')

options(14) = 500000;
minstuff3 = fmins('min3',[-2.7985,34.61e-3,.2,.1],options,[],r,om)
m = minstuff3(1);
d = minstuff3(2);
rho=minstuff3(3);
k=minstuff3(4);
om = [50:1:500]*2*pi;
r3 = (m*om.*om-i*(d-rho*c)*om-k)./(m*om.*om-i*(d+rho*c)*om-k);

plot(om,real(r3));
hold on
plot(om,imag(r3),'--');
hold off
legend('Real Data','Imaginary Data','Real Model','Imaginary Model',0)
title('Hard Wall Data and Model w/ Oscillating BC')