Here is a list of all topics with brief descriptions:

<sp/fft.h>: FFT
<sp/fileio.h>: File I/O
<sp/filter.h>: Filtering
<sp/matrix.h>: Matrix
<sp/sp.h>: Basic Definitions
<sp/vector.h>: Vector
<sp/vmath.h>: Math Functions for Vector
<sp/voperate.h>: Vector Operation
<sp/window.h>: Window Functions