Scicos Block
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Convolution block

Contents

• Convolution block
  • Palette
  • Description
  • Basic blocks equivalent model
  • Dialog box
  • Default properties
  • Interfacing function
  • Computational function
  • See also
  • Authors
  • Bibliography

Palette

• Signal - Signal palette

Description

This block realizes a discrete convolution with Fourier Transforms and overlap-add method. The input vector u, of size nu is convolved by an impulse response vector of size nb_coef, defined in the dialogue parameter 'Vector of impulse response'. The result is then delivred in the output vector y of size ny=nu.

Basic blocks equivalent model

Dialog box

• Size of inputs
  The size of the input vector.
  Type 'vec' of size 1.

• Vector of impulse response
  The vector which defines the impulse response.
  Type 'vec' of size -1.

• Inherit (no:0, yes:1)
  Herits events by its regular input ports (disable the event input port).
  Type 'vec' of size 1.

• Plot impulse response (0/1)?
  Plot the impulse response vector in a graphic window. The integer number gives the id of the window.
  Type 'vec' of size 1.

Default properties

• always active: no
• direct-feedthrough: no
• zero-crossing: no
• mode: no
• regular inputs:
  - port 1 : size [256,1] / type 1
  
• regular outputs:
  - port 1 : size [256,1] / type 1
  
• number/sizes of activation inputs: 0
• number/sizes of activation outputs: 0
• continuous-time state: no
• discrete-time state: yes
• object discrete-time state: no
• name of computational function: convol

Interfacing function

• MODNUMCOS/macros/scicos_blocks/Signal/CONVOLGEN_f.sci [view code]

Computational function

• MODNUMCOS/routines/signal/convol.c (Type 4) [view code]

See also

• RIFGEN_f - Generic Finite Impulse Response filter block (Scicos Block)
• FFTCMPLX_f - Fast Fourier Transform block (Scicos Block)
• VECTMULTCMPLX_f - Complex vector multiplier block (Scicos Block)
• INSERZEROVEC_f - Zero insertion block (Scicos Block)
• OVERLAP_f - Overlap block (Scicos Block)
• convolr_c - finite impulse response filter by fft and overlap-add method computational routine (Low level routine)
• convolfft_c - signal by impulse response multiplication with fft method computational routine (Low level routine)

Authors

IRCOM Group Alan Layec

Bibliography

Signal Processing with Scilab. Available : http://www.scilab.org/doc/signal.pdf