R help - Dec 2013 - notch filter in R

Hi everybody,

I am dealing with a time series of eeg data and I need to filter them 
with a notch filter. However, I could only find the function notch() in 
the RTisean package. Unfortunately, this function is not implemented 
yet. Is there another package/function in R which performs such a filtering?

Thanks in advance for your help.

With best regards,

Soeren Groettrup

Dear Soeren Groettrup,


Re:

> I am dealing with a time series of eeg data and I need to filter them with
a notch filter. However, I could only find the function notch() in the RTisean
package. Unfortunately, this function is not implemented yet. Is there another
package/function in R which performs such a filtering?


The 'signal' package contains many filter functions, such as
Butterworth:

butter(n, W, type = c("low", "high", "stop",
"pass"),

The "stop" version is probably what you are looking for. 
As in a band pass filter, the upper and lower frequencies must be given, as
fraction of the sample frequency (so W is a vector with two values).
Hope this helps,With best wishes,

Franklin
--




Dr. Franklin Bretschneider
Dept of Biology
Utrecht Unversity
Padualaan 8
3584 CH  Utrecht
The Netherlands
f.bretschneider@uu.nl



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