Function File: triang (m)

Return the filter coefficients of a triangular window of length m. Unlike the Bartlett window, triang does not go to zero at the edges of the window. For odd m, triang (m) is equal to bartlett (m + 2) except for the zeros at the edges of the window.

See also: bartlett.

Demonstration 1

The following code

 subplot(221);
 n=7; k=(n-1)/2; t=[-k:0.1:k]/(k+1);
 plot(t,1-abs(t),";continuous;",[-k:k]/(k+1),triang(n),"g*;discrete;");
 axis([-1, 1, 0, 1.3]); grid("on");
 title("comparison with continuous for odd n");

 subplot(222);
 n=8; k=(n-1)/2; t=[-k:0.1:k]/(k+1/2);
 plot(t,1+1/n-abs(t),";continuous;",[-k:k]/(k+1/2),triang(n),"g*;discrete;");
 axis([-1, 1, 0, 1.3]); grid("on");
 title("note the higher peak for even n");

 subplot(223);
 n=7;
 plot(0:n+1,bartlett(n+2),"g-*;bartlett;",triang(n),"r-+;triang;");
 axis; grid("off");
 title("n odd, triang(n)==bartlett(n+2)");

 subplot(224);
 n=8;
 plot(0:n+1,bartlett(n+2),"g-*;bartlett;",triang(n),"r-+;triang;");
 axis; grid("off");
 title("n even, triang(n)!=bartlett(n+2)");

Produces the following figure

Figure 1

Package: signal