Matlab - Señal triangular periodica

dx=0.5;

t=0:dx:2;

n=5;

sing=abs(-30.*t+30)-30;

c=round(length(sing)/2);

m=30;

sing=[sing(1:c) sing(c)+m sing(c+1:end)+m sing(end)];

tseg=[t(1:c) t(c) t(c+1:end) t(end)];

sing2=sing; tseg2=tseg;

for i=2:n

sing2=[sing2 sing];

tseg2=[tseg2 tseg+(2)*(i-1)];

end

plot(tseg2,sing2)

axis([0,10,-50,50])

clear all

close all

x=[0 1   ];

y=[0  -5  ];

for i=1:7

     x=[x [i i+1]];

    y=[y  (-1)^i*([0 -5])];

end

plot(x,y)

xlabel('time(sec)')

grid on

t=0:dx:2;

n=5;

sing=abs(-30.*t+30)-30;

clear all

close all

amplitud=60;

periodo=40;

x=[0 periodo/2 ];

y=[0 -amplitud/2 ];

for i=1:9

     x=[x [i  (i+1)]*periodo/2];

    y=[y  (-1)^i*([0 -amplitud/2])];

end

x=[x (i+1)*periodo/2]

y=[y 0]

plot(x,y,'r')

xlabel('time(sec)')

grid on