Matlab for beginners continue...

Here are some example to understand the discrete function in signal system engineering.....

% Plot unit step sequence , sinusoidal sequence exponential sequence
% to generate a unit step sequence
N= 31;
x1 =  ones(1,N);   % the one give 1 by N matrix of ones
n = 0:1:N-1;
subplot(2,2,1),stem(n,x1);  % stem is use to plot descret point
xlabel('n'),ylabel('x_1(n)');
title('Unit Step Sequence');   % title command give the title of graph
axis([0 30 0 2]);

%sinusoidal sequence
x2= 2*cos(.1*pi*n);
subplot(2,2,2),stem(n,x2);
xlabel('n'),ylabel('x_2(n)');
title('Sinusoidal Sequence');

%Exponetial Sequence
x3= 0.6.^(n);
subplot(2,2,3),stem(n,x3);
xlabel('n'),ylabel('x_3(n)');
title('Exponential Sequence');

% Addition of two sinusoidal sequence
x4 = sin(.5*pi*n)+ sin(.25*pi*n)
subplot(2,2,4),stem(n,x4);
xlabel('n'),ylabel('x_4(n)');
title('Addition of two Sequence');

% plot a typical exponental sequence a^n when 1. 0<a<1 ,2. -1<a<0...
...3. a>1, 4. a<-1
 
clear all;
a= .8
n= -10:1:10;
x1 = a.^n;
subplot(2,2,1),stem(n,x1);
xlabel('n'),ylabel('x_1(n)');

a=-0.8;
x2 = a.^n;
subplot(2,2,2),stem(n,x2);
xlabel('n'),ylabel('x_2(n)');

a=1.15;
x3 = a.^n;
subplot(2,2,3),stem(n,x3);
xlabel('n'),ylabel('x_3(n)');

a= -1.15;
x4 = a.^n;
subplot(2,2,4),stem(n,x4);
xlabel('n'),ylabel('x_4(n)');

%plot impulse , step and ramp signal

clear all;
n = -4:1:4;

% impulse sequence
x1 = [zeros(1,4),1,zeros(1,4)];
subplot(3,1,1),stem(n,x1);
xlabel('n'),ylabel('x_1(n)');
title('Unit Impulse sequence');

%unit step sequence
x2 = [zeros(1,4),ones(1,5)];
subplot(3,1,2),stem(n,x2);
xlabel('n'),ylabel('x_2(n)');
title('Unit step sequence');

%unit ramp
n1= 0:1:10;
x3=n1;
subplot(3,1,3),stem(n1,x3);
xlabel('n'),ylabel('x_3(n)');
title('Unit ramp sequence');

The MATLAB file is avaliable at ELECTRODATA

DOWNLAOD