medfilt1 {signal}R Documentation

Median filter

Description

Performs an n-point running median. For Matlab/Octave compatibility.

Usage

medfilt1(x, n = 3, ...)

MedianFilter(n = 3)

## S3 method for class 'MedianFilter':
filter(filt, x, ...)

Arguments

x signal to be filtered.
n size of window on which to perform the median.
filt filter to apply to the signal.
... additional arguments passed to runmed.

Details

medfilt1 is a wrapper for runmed.

Value

For medfilt1, the filtered signal of length(x).
For MedianFilter, a class of "MedianFilter" that can be used with filter to apply a median filter to a signal.

Author(s)

Tom Short.

References

http://en.wikipedia.org/wiki/Median_filter

Octave Forge http://octave.sf.net

See Also

runmed, median, filter

Examples

t = seq(0, 1, len=100)                           # 1 second sample
x = sin(2*pi*t*2.3) + 0.25*rlnorm(length(t),.5)  # 2.3 Hz sinusoid+noise
plot(t, x, type = "l")
# 3-point filter
lines(t, medfilt1(x), col="red", lwd=2) 
# 7-point filter
lines(t, filter(MedianFilter(7), x), col = "blue", lwd=2) # another way to call it

[Package signal version 0.5 Index]