The window length .
The Bartlett window is very similar to a triangular window as returned by the triang function. The Bartlett window always ends with zeros at samples 1 and n, however, while the triangular window is nonzero at those points. For L odd, the center L-2 points of bartlett(L) are equivalent to triang(L-2).
Create a 64-point Bartlett window and display the result using WVTool:
 Oppenheim, A.V., and R.W. Schafer. Discrete-Time Signal Processing. Upper Saddle River, NJ: Prentice-Hall, 1999, pp. 468-471.