function g = er_add(f1,f2)
% function g = er_add(f1,f2)
%   Function to add given transfer functions in the frequency domain.  Takes
%   two input structs F1 and F2 with complete transfer function coefficient 
%   vectors and returns result in struct G.
%
%   Author:  Evan Ruzanski, CU-Boulder, ECEN5632 MATLAB assignment, FA2004

% Unpack input struct
num1 = f1(1).tf_complete;
den1 = f1(2).tf_complete;
num2 = f2(1).tf_complete;
den2 = f2(2).tf_complete;

% Perform polynomial addition
num3 = conv(num1,den2) + conv(num2,den1);
den3 = conv(den1,den2);

% Repack output struct
f1(1).tf_complete = num3;
f1(2).tf_complete = den3; 
g = f1;