Circular Convolution of the two Sequences

The program code is :

clc

clear all

close all

X1=input('ENTER THE SEQUENCE 1 >');

i1=input('ENTER THE STARTING INDEX OF THE SEQUENCE 1 >');

X2=input('ENTER THE SEQUENCE 2 >');

i2=input('ENTER THE STARTING INDEX OF THE SEQUENCE 2 >');

m1=length(X1);

m2=length(X2);

if(m1>m2)

    Y=cconv(X1,X2,m1)

    n3=(i1+i2):(i1+i2+m1-1);

else

    Y=cconv(X1,X2,m2)

    n3=(i1+i2):(i1+i2+m2-1);

end

Yref=conv(X1,X2)

n1=i1:i1+m1-1;

n2=i2:i2+m2-1;

n4=(i1+i2):(length(Yref)-1+i1+i2);

subplot(4,1,1)

stem(n1,X1,'r')

xlabel('n');

ylabel('Amplitude');

title('Sequence 1');

subplot(4,1,2)

stem(n2,X2,'g')

xlabel('n');

ylabel('Amplitude');

title('Sequence 2');

subplot(4,1,3)

stem(n3,Y,'c')

xlabel('n');

ylabel('Amplitude');

title('Circular Convolution of the Above two sequences');

subplot(4,1,4)

stem(n4,Yref,'r')

xlabel('n');

ylabel('Amplitude');

title('Linear Convolution of the Above two sequences');

output is :

Please feel free to ask your doubts in comment session