Hi Danny,

The option '-autobad on' equals to '-autobad 1' and performs new
bad channel search for each new data buffer (see the User Guide
Section 3.3.1). Thus, the bad channel set may vary during the run.

The strange channel number is a minor bug which I will try to fix for 
the next version.

Option '-autobad 16' scans first 16 data tags and marks the bad channels
found more than 2 times as static bad ones. Thereafter the bad channel
search is not done during data processing.

Best regards, Jukka Nenonen


Danny Mitchell wrote:
> Hello,
> 
> I have just run maxfilter with the options:
> -autobad on -skip 16 99999
> to use the first few data buffers to detect statically bad channels in a 
> continuous data file.
> Occasionally a channel is reported with a surprisingly large number as 
> in the example output below:
> 
>  >     --- Processing raw tag #b = 14/890 (#t = 13.000) ---
>  >     Detected 1 flat channels: 1812
>  >     Using direct pseudo-inverse...
>  >     Processed raw data buffer with 1000 samples.
>  >
>  >     --- Processing raw tag #b = 15/890 (#t = 14.000) ---
>  >     Detected 1 flat channels: 1812
>  >     Detected 1 bad channels: 135658288
>  >     Using direct pseudo-inverse...
>  >     Processed raw data buffer with 1000 samples.
>  >
>  >     --- Processing raw tag #b = 16/890 (#t = 15.000) ---
>  >     Detected 1 flat channels: 1812
>  >     Using direct pseudo-inverse...
>  >     Processed raw data buffer with 1000 samples.
> 
> 
> When I tried again with the options:
> -autobad 16 -skip 16 99999
> the "bad channel 135658288" was no longer reported (although the flat 
> one was).
> 
> So I have two questions:
> 1) What is this strange channel number?
> 2) Does the automatic bad channel detection for the first few data 
> buffers differ for the two options, and, if so, how?
> 
> 
> Many thanks,
> Danny


-- 

================================
Dr. Jukka Nenonen
Manager, Method development
Elekta Neuromag Oy
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