more_octave_examples [JAY FREE]

More example programs for Octave.

Note

Please read this page(Experiments using Octave for b-tech course) before going through the examples.
Basic knowledge of Octave or Matlab is required.

Example Programs

Program P1_1

% Generation of a Unit Sample Sequence 
clf;
% Generate a vector from -10 to 20
n = -10:20;
% Generate the unit sample sequence
u = [zeros(1,10) 1 zeros(1,20)];
% Plot the unit sample sequence
stem(n,u);
xlabel('Time index n');ylabel('Amplitude');
title('Unit Sample Sequence');
axis([-10 20 0 1.2]);

Program P1_2

% Generation of a complex exponential sequence
clf;
c = -(1/12)+(pi/6)*i;
K = 2;
n = 0:40;
x = K*exp(c*n);
subplot(2,1,1);
stem(n,real(x));
xlabel('Time index n');ylabel('Amplitude');
title('Real part');
subplot(2,1,2);
stem(n,imag(x));
xlabel('Time index n');ylabel('Amplitude');
title('Imaginary part');

Program P1_3

% Generation of a real exponential sequence
clf;
n = 0:35; a = 1.2; K = 0.2;
x = K*a.^n;
%stem(n,x);
plot(n,x);
xlabel('Time index n');ylabel('Amplitude');

Program P1_4

% Generation of a sinusoidal sequence
n = 0:40;	
f = 0.1;			
phase = 0;			
A = 1.5;			
arg = 2*pi*f*n - phase; 
x = A*cos(arg);
clf;			% Clear old graph
stem(n,x);		% Plot the generated sequence
axis([0 40 -2 2]);
grid; 
title('Sinusoidal Sequence');
xlabel('Time index n');
ylabel('Amplitude');
axis;

Program P1_5

% Signal Smoothing by Averaging
clf;
R = 51;
d = 0.8*(rand(R,1) - 0.5); % Generate random noise
m = 0:R-1;
s = 2*m.*(0.9.^m); % Generate uncorrupted signal
x = s + d'; % Generate noise corrupted signal
subplot(2,1,1);
plot(m,d','r-',m,s,'g--',m,x,'b-.');
xlabel('Time index n');ylabel('Amplitude');
legend('d[n] ','s[n] ','x[n] ');
x1 = [0 0 x];x2 = [0 x 0];x3 = [x 0 0];
y = (x1 + x2 + x3)/3;
subplot(2,1,2);
plot(m,y(2:R+1),'r-',m,s,'g--');
legend( 'y[n] ','s[n] ');
xlabel('Time index n');ylabel('Amplitude');

Program P1_6

% Generation of amplitude modulated sequence
clf;
n = 0:100;	
m = 0.4;fH = 0.1; fL = 0.01;				
xH = sin(2*pi*fH*n);
xL = sin(2*pi*fL*n);
y = (1+m*xL).*xH;
stem(n,y);grid;
xlabel('Time index n');ylabel('Amplitude');

Program P1_7

% Generation of a swept frequency sinusoidal sequence
n = 0:100;
a = pi/2/100;
b = 0;
arg = a*n.*n + b*n;
x = cos(arg);
clf;				
stem(n, x);
axis([0,100,-1.5,1.5]);
title('Swept-Frequency Sinusoidal Signal');
xlabel('Time index n');
ylabel('Amplitude');
grid; axis;