##
median

median —
A median filter, a variant FIR lowpass filter.

## Description

Implementation of a median filter.

## Syntax

ares **median** asig, 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

*asig* -- input signal 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.

*median* 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 median opcode. It uses the file *median.csd*.

**Example 417. Example of the median opcode.**

See the sections *Real-time Audio* and *Command Line Flags* for more information on using command line flags.

<CsoundSynthesizer>
<CsInstruments>
sr = 44100
kr = 441
ksmps = 100
nchnls = 1
instr 1
a1 oscil 30000, 10, 1
a2 median a1, 5, 8
out a2
endin
</CsInstruments>
<CsScore>
f1 0 4096 10 1
i 1 0 0.1
e
</CsScore>
</CsoundSynthesizer>

## Credits

Author: John ffitch |

University of Bath |

May 2010 |

New in Csound version 5.13