Here are the classes, structs, unions and interfaces with brief descriptions:

Nfilter	Contains digital signal filtering algorithms
Nband_pass
CBPF_2	Second-order band-pass filter
Nband_stop
CBSF_2	Second-order band-stop filter
Nhigh_pass
CHPF_1	First-order high-pass filter
CHPF_2	Second-order high-pass filter
Nlimiter
CSRL	Slew-rate limiter
Nlow_pass
CLPF_1	First-order low-pass filter
CLPF_2	Second-order low-pass filter
CMA	Fixed-window moving-average low-pass filter