From kozick@charcoal.eg.bucknell.edu Mon Sep 15 14:04 EDT 1997
Date: Mon, 15 Sep 1997 14:03:31 -0400
From: Kozick Rich  <kozick@charcoal.eg.bucknell.edu>
To: gamache@bucknell.edu, louie@bucknell.edu, dkline@bucknell.edu,
        rbrooks@bucknell.edu, vary@bucknell.edu, dseiler@bucknell.edu,
        suqi@bucknell.edu, reed@bucknell.edu, mwtaylor@bucknell.edu,
        keeney@bucknell.edu, mmccrthy@bucknell.edu, blixt@bucknell.edu,
        sgordon@bucknell.edu, pankake@bucknell.edu, ganiear@bucknell.edu,
        campbell@bucknell.edu, michael@bucknell.edu, jcarey@bucknell.edu,
        pickert@bucknell.edu, sweet@bucknell.edu, bixby@bucknell.edu,
        eneff@bucknell.edu, vallone@bucknell.edu, hajdu@bucknell.edu,
        kmehaffy@bucknell.edu, pribik@bucknell.edu, ligong@bucknell.edu,
        kozick@bucknell.edu
Subject: Sample for HW 8

Hi,

To help you with the MATLAB program for Homework 8 in ELEC 320, I have
provided a sample program for part (a) of problem 1.34.  The program
is available at

http://www.eg.bucknell.edu/~kozick/elec320/hw8s.m

It is also linked to the "Homework" section of the course home page.
The program hw8s.m is also attached to this email message.

Thank you.


Rich Kozick

% =================
% Sample MATLAB program for Homework 8:  Problem 1.34 in the Kamen/Heck text.
%
% ELEC 320, Fall 1997, Rich Kozick

% NOTE:  MATLAB does not allow an index of zero in vectors.
%        Thus the array index will be one greater than the time index.
%        In other words, the discrete-time signal value y[n] will be
%        stored at array location y[n+1].

% Parts a-e:  y[n] = 0.5*y[n-1] + x[n],  n = 0, 1, ..., 10
%             with initial condition y[-1] = 0.

n = 0:10;	% Vector of times at which we will evaluate system output.
                % This will be used for plotting.

% Part a: x[n] = u[n], output y1[n]

x = 1;
y1(1) = x;	% Do time n=0 separately to handle initial condition.

for i=2:11	% Compute system outputs for times 1, 2, ..., 10
  x = 1;
  y1(i) = 0.5*y1(i-1) + x;
end

figure(1)	% Plot output signal y1[n]
stem(n, y1)
title('Problem 1.34 (a)')
xlabel('Time index (n)')
ylabel('y1[n]')