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mediank

A median filter, a variant FIR lowpass filter.

Syntax

kres mediank kin, ksize, imaxsize [, iskip]

Initialization

imaxsize -- the maximun size of the window used to select the data.

iskip -- initial disposition of internal data space. A zero value will clear the space; a non-zero value will allow previous information to remain. The default value is 0.

Performance

kin -- krate value to be filtered

ksize -- size of the window over which the input is to be filtered. It must not exceed the maximum window size; if it does it is truncated.

mediank is a simple filter that retuns the median value of the last ksize values. It has a lowpass action. The efficiency decreases as the window size increases.

Examples

Here is an example of the mediank opcode. It uses the file mediank.csd.

Example of the mediank opcode.
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<CsoundSynthesizer>
<CsOptions>
-n
</CsOptions>
<CsInstruments>
sr = 44100
kr = 147
ksmps = 300
nchnls = 1

instr 1
  k1  oscil  100, 10, 1
  k2  mediank k1, 5, 8
  printk 0, k2
endin
</CsInstruments>

<CsScore>
f1 0 4096 10 1
i 1 0 1 
e

</CsScore>

</CsoundSynthesizer>

See also

Standard filters: Variant FIR lowpass filter

Credits

Author: John ffitch
University of Bath
May 2010

New in Csound version 5.13