— Command: filter-length n

This command sets the filter length to n. The filter length is the number of filter coefficients.

— Command: sampling-frequency f

This command sets the sampling frequency to f. All other frequencies in a specification file must belong to the band [0..f/2].

— Command: sine-symmetry
— Command: cosine-symmetry

The command (sine-symmetry) specifies that the frequency response H(f) is an odd function, i.e., H(-f) = - H(f). The command (cosine-symmetry) specifies that the frequency response H(f) is an even function, i.e., H(f) = H(f). The default is (cosine-symmetry).

— Command: title t

Set the filter title to t, which is a string. The title is used for documentation purposes only. If unspecified, the title equals the string "UNTITLED".