Signal package

The signal package is part of the Octave Forge project and provides signal processing algorithms for use with Octave. The functions provided by the signal package include creation of waveforms, FIR and IIR filter design, spectral analysis, Fourier and other transforms, window functions, and resampling and rate changing. There are also some wavelet functions included, because there is no separate wavelet package, at least for now.

You may also be interested in the LTFAT package.

Contribution

There are many ways to contribute to the development and maintenance of the signal processing package, including but not limited to testing, writing new test cases, reviewing and editing documentation, creating useful demos or examples of how to use the functions in the package, fixing bugs in existing functions, improving compatibility with Matlab, and writing completely new functions.

Missing Tests

Octave functions can be written to include their own built-in self tests that work with the test function, see Tests.

Several functions in the signal package do not have exhaustive test suites or do not include any built-in self tests at all. This is a list of functions in the signal package that do not yet have any tests.

ar_psd
arburg
aryule
besselap
bilinear
buttap
cceps
cheb
cheb1ap
cheb2ap
clustersegment
cmorwavf
cohere
cpsd
csd
dct
dct2
dctmtx
dftmtx
diric
dwt
ellipap
firls
freqs
freqs_plot
gmonopuls
hilbert
idct
idct2
iirlp2mb
interp
invfreq
invfreqs
invfreqz
kaiserord
levinson
mexihat
meyeraux
morlet
movingrms
mscohere
ncauer
pburg
polystab
primitive
pwelch
pyulear
qp_kaiser
sampled2continuous
sawtooth
schtrig
sftrans
sgolayfilt
shanwavf
sigmoid_train
square
ss2tf
ss2zp
tf2ss
tf2zp
tfe
tfestimate
wconv
wkeep
wrev
xcorr
xcov
zp2ss
zp2tf
zplane

Missing Functions

This is a list of functions that are not yet implemented in the Octave signal package. Patches for some of these functions are available on the patch tracker and are undergoing review. You could help us by implementing the missing functions and adding them to the patch tracker, or by helping us review the ones that are already there. This list is subject to change and may not be complete in any sense. However, it is a starting point when looking for missing functionality or for possible projects to work on.

Signal Generation

demod
modulate (see patch #9409)
seqperiod
strips
vco

Correlation and Convolution

corrmtx
dtw (please refer to open feature request bug #51572, only pseudocode so far)

Signal Measurement

bandpower (see patch #8697)
dutycycle
enbw
falltime
midcross
overshoot
pulseperiod
pulsesep
pulsewidth
risetime
settlingtime
sfdr
slewrate
statelevels (see patch #9199)
undershoot

Filter Analysis

filternorm
filtord
firtype
impzlength
isallpass
islinphase
ismaxphase
isminphase
isstable (see patch #9265)
phasedelay
phasez
stepz (see patch #8630)
zerophase

Filter Conversion

cell2sos
filt2block
latc2tf
latcfilt
realizemdl
sos2cell
sos2ss
ss2sos
tf2latc
tf2zpk

FIR Filter Design

cfirpm
equiripple
fircls
fircls1
firpm (see patch #8535)
firpmord
firrcos
freqsamp
gaussfir
intfilt
kaiserwin
maxflat
polyscale

IIR Filter Design

lp2bp
lp2bs
lp2hp
lp2lp (please refer to open feature request bug #46440, only partial code snippets so far)
yulewalk

Transforms

goertzel (see patch #8495)
icceps

Spectral Analysis

db
pcov
peig
pmcov
pmtm (please refer to open feature request bug #55714)
pmusic
rooteig
rootmusic
spectrogram (please refer to open feature request bug #45232)

Window Functions

dpss
dpssclear
dpssdir
dpssload
taylorwin (see patch #8506)

System Identification

ac2poly
ac2rc
arcov
armcov
is2rc
lar2rc
lpc (see patch #8575)
lsf2poly (see patch #8726)
poly2ac
poly2lsf (see patch #8726)
poly2rc
prony
rc2ac
rc2is
rc2lar
rc2poly
rlevinson
schurrc
stmcb

Object Oriented Filter Design

design
designmethods
designopts
fdesign
fdesign.arbmag
fdesign.bandpass
fdesign.bandstop
fdesign.differentiator
fdesign.highpass
fdesign.hilbert
fdesign.lowpass
fdesign.pulseshaping
setspecs
validstructures

Interactive Design Tools

dspfwiz
fdatool
filterbuilder
sptool
wintool
wvtool