what is function of [ ] in this code

Here is the code

h1336=[];
L=50;
fs=8000;
fb=1336;
h1336 = (2/L)*cos(2*pi*fb*(0:L-1)/fs);
[H,F] = freqz(h1336,1,[],fs);

What does this bracket [ ] do in freqz command

Answer 1

[Wayne King]

It says "use the default value for the input N, the number of frequency points".

in freqz() that is 512.

So

[H,F] = freqz(h1336,1,[],fs);

is the same as:

[H,F] = freqz(h1336,1,512,fs);

[moonman]

Thanks a lot

Answer 2

[Walter Roberson]

http://www.mathworks.com/help/toolbox/signal/ref/freqz.html

If you do not specify the integer n, or you specify it as the empty vector [], the frequency response is calculated using the default value of 512 samples.