NRZ-I signal matlab code

//codes for NRZ-I in matlab

clc;
clear;
x=[0 1 0 1 0 0 0 1 1 0 1 1 0 0 0 1];
T=length(x);
n=200;
N=n*T;
dt=T/N;
pulse=-1;
t=0:dt:T;
y=zeros(1,length(t));
  for i=0:T-1;
    if x(i+1)==1
        if pulse==1
            pulse=-1;
            y(i*n+1 : (i+1)*n)=-1;
        else
            pulse=1;
            y(i*n+1 : (i+1)*n);
        end;
    else
        y(i*n+1 : (i+1)*n)=pulse;
    end;
  end;
  plot(t,y);
  axis([0 t(end) -2 2]);
  grid on;
  title('NRZ-I');
 
//end;


the output is:-

this is the output as we given input