Signal

Scilab Function
Last update : 12/01/2004

Signal - Signal manual description

### Filters

  - analpf : analog low-pass filter
  - buttmag : squared magnitude response of a Butterworth filter
  - casc : creates cascade realization of filter
  - cheb1mag : square magnitude response of a type 1 Chebyshev filter
  - cheb2mag : square magnitude response of a type 1 Chebyshev filter
  - chepol : recursive implementation of Chebychev polynomial
  - convol : convolution of 2 discrete series
  - ell1 mag : squared magnitude of an elliptic filter
  - eqfir : minimax multi-band, linear phase, FIR filter
  - eqiir : design of iir filter
  - faurre : optimal lqg filter.
  - lindquis : optimal lqg filter lindquist algorithm
  - ffilt : FIR low-pass,high-pass, band-pass, or stop-band filter
  - filter : compute the filter model
  - find_freq : parameter compatibility for elliptic filter design
  - findm : for elliptic filter design
  - frmag : magnitude of the frequency responses of FIR and IIR filters.
  - fsfirlin : design of FIR, linear phase (frequency sampling technique)
  - fwiir : optimum design of IIR filters in cascade realization,
  - iir : designs an iir digital filter using analog filter designs.
  - iirgroup : group delay of iir filter
  - iirlp : Lp IIR filters optimization
  - group : calculate the group delay of a digital filter
  - optfir : optimal design of linear phase filters using linear programming
  - remezb : minimax approximation of a frequency domain magnitude response.
  - kalm : Kalman update and error variance
  - lev : resolve the Yule-Walker equations :
  - levin : solve recursively Toeplitz system (normal equations)
  - srfaur : square-root algorithm for the algebraic Riccati equation.
  - srkf : square-root Kalman filter algorithm
  - sskf : steady-state Kalman filter
  - system : generates the next observation given the old state
  - trans : transformation of standardized low-pass filter into low-pass, high-pass, band-pass, stop-band.
  - wfir : linear-phase windowed FIR low-pass, band-pass, high-pass, stop-band
  - wiener : Wiener estimate (forward-backward Kalman filter formulation)
  - wigner : time-frequency wigner spectrum of a signal.
  - window : calculate symmetric window
  - zpbutt : Butterworth analog filter
  - zpch1 : poles of a type 1 Chebyshev analog filter
  - zpch2 : poles and zeros of a type 2 Chebyshev analog filter
  - zpell : poles and zeros of prototype lowpass elliptic filter

### Spectral estimation

  - corr : correlation coefficients
  - cspect : spectral estimation using the modified periodogram method.
  - czt : chirp z-transform algorithm
  - intdec : change the sampling rate of a 1D or 2D signal
  - mese : calculate the maximum entropy spectral estimate
  - pspect : auto and cross-spectral estimate
  - wigner : Wigner-Ville time/frequency spectral estimation

### Transforms

  - dft : discrete Fourier transform
  - fft : fast flourier transform
  - hilb : Hilbert transform centred around the origin.
  - hank : hankel matrix of the covariance sequence of a vector process
  - mfft : fft for a multi-dimensional signal

### Identification

  - lattn,lattp : recursive solution of normal equations
  - phc : State space realisation by the principal hankel component approximation method,
  - rpem : identification by the recursive prediction error method

### Miscellaneous

  - lgfft : computes p = ceil (log_2(x))
  - sinc : calculate the function sin(2*pi*fl*t)/(pi*t)
  - sincd : calculates the function Sin(N*x)/Sin(x)
  - %k : Jacobi's complete elliptic integral
  - %asn : .TP the elliptic integral :
  - %sn : Jacobi 's elliptic function with parameter m
  - bilt : bilinear transform or biquadratic transform.
  - jmat : permutes block rows or block columns of a matrix