[FieldTrip] change in yokogawa trigger and raw data handling
r.oostenveld at donders.ru.nl
Thu Apr 28 14:31:43 CEST 2011
Dear Yokogawa users
Earlier this week I made a change to the handling of Yokogawa data
that might require some small updates to your analysis scripts. Let me
summarise it in this mail.
Although most of the meta information and header information is still
read with the yokogawa p-files, the sqd data can now also be read with
the sqdproject/sqdread function. As of this week the code is included
in fieldtrip/external/sqdproject and will automatically be added to
The consequence is that much less memory is needed if you only want to
read a few channels (or the trigger channels). You can now use it on a
small memory computer.
Another consequence is that data is expressed in fT and mV (if I am
correct) and not no T and V, so please note the scaling difference.
Furthermore, I have added an option to ft_read_event/read_trigger that
automatically detects whether you have downgoing or upgoing flanks in
the data. It used to detect both, and then it was up to you to select
e.g. '169_up' as the relevant one. It will now (try to) autodetect
whether your data has downgoing or upgoing flanks and only detect the
triggers for the approprate one. The resulting trigger code does not
have the down/up tag any more, so you should now work with '169'
And finally the ft_read_event function now has the 'trigindx' option
documented (see also http://bugzilla.fcdonders.nl/show_bug.cgi?id=494#c2)
and has an option 'threshold' for the flank detection in the analog
PS if you want to follow up to this mail with potential problems or
suggestions for improvements, please use http://bugzilla.fcdonders.nl
and file a "bug" for the yokogawa component.
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