The options are:
Artifacts rejected by the polarity inversion test (i.e. blinks) are given special treatment because they are the only type of artifact that can be corrected. When avg runs with the -a option, events with polinv artifacts are excluded from the bin averages along with events containing other artifacts as specified by the tests in the artifact rejection file. However, if avg is also run with the -b option, the blinks can be corrected later with blinkcp(1) . In this case, the polinv rejected events will be corrected and included in the corrected bin average. Giving polinv artifacts a unique log flag allows these blink events to be identified. This can be useful, for instance, if one wishes to compute behavioral measures based only on EEG events that were not rejected. Before applying blinkcp(1) , the polinv events are rejected, after blinkcp(1) they are not: the polinv log flag allows you to keep track of these events.
When the -x option is specified, the log file is processed to clear the above flag bits prior to averaging. If the -x option is not used, the log file is read only to ascertain that the data file, logfile, and binlist files belong together and to detect mismatches. In this case the log entries corresponding to the events that are rejected remain as they were, and the bits are not cleared prior to processing.
Note that only events selected for averaging are tested for data error or artifact rejection, so when using the -x option only the events rejected from this set are marked in the log file.
This is one way to enable the average of long epochs, but be aware of the resulting loss of resolution in the waveform - specifying a dec_factor of 2 will effectively reduce 250Hz sampled data to 125Hz sampled data.
Also see the -c option for enabling the average of long epochs.
This is one way to enable the average of long epochs, but be aware of the increase in the size of the average file - doubling the size of the epoch will pretty much double the size of the average file.
Also see the -r option for enabling the average of long epochs.
If all is well following invocation, avg will print out:
Enter raw, log, and bin list filenames...
As long as there remain files to be averaged, specify them here. When averaging is complete, a summary of the various bins and certain data parameters is printed on the standard output.