Signal Processing Toolbox

Functions -- Categorical List

This section contains brief descriptions of all functions in the Signal Processing Toolbox arranged by category.

FIR Digital Filter Design

IIR Digital Filter Design

IIR FIlter Order Estimation

Filter Analysis

Filter Implementation

Analog Lowpass Filter Prototypes

Analog Filter Design

Analog Filter Transformation

Filter Discretization

Linear System Transformations

Windows

Transforms

Cepstral Analysis

Statistical Signal Processing and Spectral Analysis

Parametric Modeling

Linear Prediction

Multirate Signal Processing

Waveform Generation

Specialized Operations

Graphical User Interfaces

FIR Digital Filter Design

Function	Description
cfirpm	Complex and nonlinear-phase equiripple FIR filter design
dfilt	Discrete-time filters
fir1	Window-based finite impulse response filter design
fir2	Frequency sampling-based finite impulse response filter design
fircls	Constrained least square FIR multiband filter design
fircls1	Constrained least square, lowpass and highpass, linear phase, FIR filter desig
firls	Least square linear-phase FIR filter design
firpm	Parks-McClellan optimal FIR filter design
firpmord	Parks-McClellan optimal FIR filter order estimation
firrcos	Raised cosine FIR filter design
gaussfir	Gaussian FIR pulse-shaping filter design
intfilt	Interpolation FIR filter design
kaiserord	Kaiser window FIR filter design estimation parameters
sgolay	Savitzky-Golay filter design

IIR Digital Filter Design

Function	Description
butter	Butterworth analog and digital filter design
cheby1	Chebyshev Type I filter design (passband ripple)
cheby2	Chebyshev Type II filter design (stopband ripple)
dfilt	Discrete-time filters
ellip	Elliptic (Cauer) filter design
filtstates	Flter states
maxflat	Generalized digital Butterworth filter design
yulewalk	Recursive digital filter design

IIR FIlter Order Estimation

Function	Description
buttord	Butterworth filter order and cutoff frequency
cheb1ord	Chebyshev Type I filter order
cheb2ord	Chebyshev Type II filter order
ellipord	Minimum order for elliptic filters

Filter Analysis

Function	Description
abs	Absolute value (magnitude) (This is a MATLAB function.)
angle	Phase angle (This is a MATLAB function.)
filternorm	2-norm or infinity-norm of a digital filter
freqs	Frequency response of analog filters
freqspace	Frequency spacing for frequency response (This is a MATLAB function.)
freqz	Frequency response of digital filters
fvtool	Filter Visualization Tool
grpdelay	Average filter delay (group delay)
impz	Impulse response of digital filters
phasedelay	Phase delay response of digital filters
phasez	Phase response of digital filters
stepz	Step response of digital filters
unwrap	Unwrap phase angles (This is a MATLAB function.)
zerophase	Zero-phase reponse of digital filters
zplane	Zero-pole plot

Filter Implementation

Function	Description
conv	Convolution and polynomial multiplication (This is a MATLAB function.)
conv2	Two-dimensional convolution (This is a MATLAB function.)
convmtx	Convolution matrix
deconv	Deconvolution and polynomial division (This is a MATLAB function.)
fftfilt	FFT-based FIR filtering using overlap-add method
filter	Filter data with recursive (IIR) or nonrecursive (FIR) filter (This is a MATLAB function.)
filter2	Two-dimensional digital filtering (This is a MATLAB function.)
filtfilt	Zero-phase digital filtering
filtic	Iinitial conditions for transposed direct-form II filter implementation
latcfilt	Lattice and lattice-ladder filter implementation
medfilt1	One-dimensional median filtering
sgolayfilt	Savitzky-Golay filtering
sosfilt	Second-order (biquadratic) IIR digital filtering
upfirdn	Upsample, apply FIR filter, and downsample

Analog Lowpass Filter Prototypes

Function	Description
besselap	Bessel analog lowpass filter prototype
buttap	Butterworth analog lowpass filter prototype
cheb1ap	Chebyshev Type I analog lowpass filter prototype
cheb2ap	Chebyshev Type II analog lowpass filter prototype
ellipap	Elliptic analog lowpass filter prototype

Analog Filter Design

Function	Description
besself	Bessel analog filter design
butter	Butterworth analog and digital filter design
cheby1	Chebyshev Type I filter design (passband ripple)
cheby2	Chebyshev Type II filter design (stopband ripple)
ellip	Elliptic (Cauer) filter design

Analog Filter Transformation

Function	Description
lp2bp	Transform lowpass analog filters to bandpass
lp2bs	Transform lowpass analog filters to bandstop
lp2hp	Transform lowpass analog filters to highpass
lp2lp	Change cutoff frequency for lowpass analog filter

Filter Discretization

Function	Description
bilinear	Bilinear transformation method for analog-to-digital filter conversion
impinvar	Impulse invariance method for analog-to-digital filter conversion

Linear System Transformations

Function	Description
latc2tf	Convert lattice filter parameters to transfer function form
polystab	Stabilize polynomial
polyscale	Scale the roots of a polynomial
residuez	z-transform partial-fraction expansion
sos2ss	Convert digital filter second-order section parameters to state-space form
sos2tf	Convert digital filter second-order section data to transfer function form
sos2zp	Convert digital filter second-order sections parameters to zero-pole-gain form
ss2sos	Convert digital filter state-space parameters to second-order sections form
ss2tf	Convert state-space filter parameters to transfer function form
ss2zp	Convert state-space filter parameters to zero-pole-gain form
tf2latc	Convert transfer function filter parameters to lattice filter form
tf2sos	Convert digital filter transfer function data to second-order sections form
tf2ss	Convert transfer function filter parameters to state-space form
tf2zp	Convert continuous-time transfer function filter parameters to zero-pole-gain form
tf2zpk	Convert discrete-time transfer function filter parameters to zero-pole-gain form
zp2sos	Convert digital filter zero-pole-gain parameters to second-order sections form
zp2ss	Convert zero-pole-gain filter parameters to state-space form
zp2tf	Convert zero-pole-gain filter parameters to transfer function form

Windows

Function	Description
barthannwin	Modified Bartlett-Hann window
bartlett	Bartlett window
blackman	Blackman window
blackmanharris	Minimum 4-term Blackman-Harris window
bohmanwin	Bohman window
chebwin	Chebyshev window
flattopwin	Flat top window
gausswin	Gaussian window
hamming	Hamming window
hann	Hann (Hanning) window
kaiser	Kaiser window
nuttallwin	Nuttall-defined minimum 4-term Blackman-Harris window
parzenwin	Parzen (de la Valle-Poisson) window
rectwin	Rectangular window
sigwin	Signal processing windows
triang	Triangular window
tukeywin	Tukey (tapered cosine) window
window	Window function gateway
wvtool	Window Visualization Tool

Transforms

Function	Description
bitrevorder	Permute input into bit-reversed order
czt	Chirp z-transform
dct	Discrete cosine transform (DCT)
dftmtx	Discrete Fourier transform matrix
digitrevorder	Permute input into digit-reversed order
fft	One-dimensional fast Fourier transform (This is a MATLAB function.)
fft2	Two-dimensional fast Fourier transform (This is a MATLAB function.)
fftshift	Rearrange FFT function outputs (This is a MATLAB function.)
goertzel	Discrete Fourier transform using second order Goertzel algorithm
hilbert	Discrete-time analytic signal using Hilbert transform
idct	Inverse discrete cosine transform
ifft	One-dimensional inverse fast Fourier transform (This is a MATLAB function.)
ifft2	Two-dimensional inverse fast Fourier transform (This is a MATLAB function.)

Cepstral Analysis

Function	Description
cceps	Complex cepstral analysis
icceps	Inverse complex cepstrum
rceps	Real cepstrum and minimum phase reconstruction

Statistical Signal Processing and Spectral Analysis

Function	Description
corrcoef	Correlation coefficient matrix (This is a MATLAB function.)
corrmtx	Data matrix for autocorrelation matrix estimation
cov	Covariance matrix (This is a MATLAB function.)
cpsd	Cross power spectral density
dspdata	DSP data parameter information
dspopts	Spectral estimation parameter information
mscohere	Magnitude squared coherence function
pburg	Power spectral density using Burg method
pcov	Power spectral density using covariance method
peig	Pseudospectrum using eigenvector method
periodogram	Power spectral density (PSD) using a periodogram
pmcov	Power spectral density using modified covariance method
pmtm	Power spectral density using multitaper method (MTM)
pmusic	Power spectral density using MUSIC algorithm
pwelch	Power spectral density (PSD) using Welch's method
pyulear	Power spectral density using Yule-Walker AR method
rooteig	Frequency and power content estimate using eigenvector method
rootmusic	Frequency and power content estimate using root MUSIC algorithm
spectrum	Spectral estimation functions
tfestimate	Transfer function estimate
xcorr	Cross-correlation function
xcorr2	Two-dimensional cross-correlation
xcov	Cross-covariance function (equal to mean-removed cross-correlation)

Parametric Modeling

Function	Description
arburg	Estimate AR model parameters using Burg method
arcov	Estimate AR model parameters using covariance method
armcov	Estimate AR model parameters using modified covariance method
aryule	Estimate AR model parameters using Yule-Walker method
ident	See the System Identification Toolbox documentation
invfreqs	Identify continuous-time filter parameters from frequency response data
invfreqz	Identify discrete-time filter parameters from frequency response data
prony	Prony's method for time domain IIR filter design
stmcb	Compute linear model using Steiglitz-McBride iteration

Linear Prediction

Function	Description
ac2poly	Convert autocorrelation sequence to prediction polynomial
ac2rc	Convert autocorrelation sequence to reflection coefficients
is2rc	Convert inverse sine parameters to reflection coefficients
lar2rc	Convert log area ratio parameters to reflection coefficients
levinson	Levinson-Durbin recursion
lpc	Linear prediction filter coefficients
lsf2poly	Convert line spectral frequencies to prediction filter coefficients
poly2ac	Convert prediction filter polynomial to autocorrelation sequence
poly2lsf	Convert prediction filter coefficients to line spectral frequencies
poly2rc	Convert prediction filter polynomial to reflection coefficients
rc2ac	Convert reflection coefficients to autocorrelation sequence
rc2is	Convert reflection coefficients to inverse sine parameters
rc2lar	Convert reflection coefficients to log area ratio parameters
rc2poly	Convert reflection coefficients to prediction filter polynomial
rlevinson	Reverse Levinson-Durbin recursion
schurrc	Compute reflection coefficients from autocorrelation sequence

Multirate Signal Processing

Function	Description
decimate	Decimation -- decrease sampling rate
downsample	Decrease sampling rate by integer factor
interp	Interpolation -- increase sampling rate by integer factor
resample	Change sampling rate by rational factor
upfirdn	Upsample, apply FIR filter, and downsample
upsample	Increase sampling rate by integer factor

Waveform Generation

Function	Description
chirp	Swept-frequency cosine
diric	Dirichlet or periodic sinc function
gauspuls	Gaussian-modulated sinusoidal pulse
gmonopuls	Gaussian monopulse
pulstran	Pulse train
rectpuls	Sampled aperiodic rectangle
sawtooth	Sawtooth or triangle wave
sinc	Sinc function
square	Square wave
tripuls	Sampled aperiodic triangle
vco	Voltage controlled oscillator

Specialized Operations

Function	Description
buffer	Buffer signal vector into matrix of data frames
cell2sos	Convert cell array for second-order sections to second-order sections matrix
cplxpair	Group complex numbers into complex conjugate pairs (This is a MATLAB function.)
demod	Demodulation for communications simulation
dpss	Discrete prolate spheroidal sequences (Slepian sequences)
dpssclear	Remove discrete prolate spheroidal sequences from database
dpssdir	Discrete prolate spheroidal sequences database directory
dpssload	Load discrete prolate spheroidal sequences from database
dpsssave	Save discrete prolate spheroidal sequences in database
eqtflength	Equalize lengths of transfer function's numerator and denominator
modulate	Modulation for communications simulation
seqperiod	Compute the period of a sequence
sos2cell	Convert second-order sections matrix to cell arrays
spectrogram	Time-dependent frequency analysis
strips	Strip plot
udecode	Decode 2n-level quantized integer inputs to floating-point outputs
uencode	Quantize and encode floating-point inputs to integer outputs

Graphical User Interfaces

Function	Description
fdatool	Filter Design and Analysis Tool
fvtool	Filter Visualization Tool
sptool	Interactive digital signal processing tool
wintool	Window Design and Analysis Tool
wvtool	Window Visualization Tool

Function Reference

Functions -- Alphabetical List

© 1994-2005 The MathWorks, Inc.