Many of Octave's standard functions are distributed as function files.
They are loosely organized by topic in subdirectories of
octave-home/lib/octave/version/m to make it easier
to find them.
The following is a list of all the function file subdirectories and the types of functions you will find there.
audio
control
elfun
general
flipud, rot90,
and triu as well as other basic functions, like
ismatrix nargchk, etc.
image
io
linear-algebra
miscellaneous
plot
polynomial
set
signal
specfun
special-matrix
startup
statistics
strings
time