Sinc funtion and Triangular function

close all;
clear all;
clc;
t=-4:0.1:4;
x=sinc(pi*t);
subplot(2,1,1);
plot(x);
xlabel('time');
ylabel('amplitude');
title('sinc function');
y=0:0.5:2;
for j=0:3
x=(4*j)+y;
subplot(2,1,2);
plot(x,y);
hold on;
end;
for k=0:3
x=(4*k)-y;
subplot(2,1,2);
plot(x,y);
hold on;
end;
hold off;

Output: