just plotting a 1 periodic function

I would like to plot a 1 periodic function and it could be piecewise linear. I have a function like below,it is a triangular function, I would like to extend the triangle with a period 1,how can I do it? thanks

function piecewise=piecew(x);
piecewise=abs(1-abs(x)).*(abs(x)<1);
end

Answer 1

[Andrew Newell]

function piecewise=piecew(x)
z = mod(x,2)-1;
piecewise=abs(1-abs(z)).*(abs(z)<1);
end

[li]

thanks