Different types of SIGNALING Schemes using MATLAB

clc
clear all
close all
n=input('enter the number of bits')
m=mod(randperm(n),2)            %binary data
t=['the binary data is      ',num2str(m)]
c=input('enter your choice 1.unipolar nrz 2.polar nrz 3.unipolar rz 4.manchester')
switch c
    case 1
for i=1:1:n
s((i-1)*100+1:i*100)=m(i)
end
    case 2
        for i=1:1:n
            if m(i)==1
                m(i)=1
            else
                m(i)=-1
            end
        end
        for i=1:1:n
s((i-1)*100+1:i*100)=m(i)
        end
    case 3
        for i=1:1:n
    s(1+100*(i-1):50*((2*i)-1))=m(i)
    s(1+50*((2*i)-1):100*i)=0
        end
    case 4
        for i=1:1:n
            if m(i)==1
                m(i)=1
            else
                m(i)=-1
            end
        end
        for i=1:1:n
    s(1+100*(i-1):50*((2*i)-1))=m(i)
    s(1+50*((2*i)-1):100*i)=-m(i)
        end
    otherwise
disp('invalid choice')
end
plot(s)
gtext(t)
switch c
    case 1
        gtext('unipolar nrz signaling')
    case 2
        gtext('polar nrz signaling')
    case 3
        gtext('unipolar rz signaling')
    otherwise
        gtaxt('manchester signaling')
end