mdh header_fileThis will start mdh going with the intention of producing a header file called header_file when all parameters have been acquired. As usual, just type mdh to get a clue as to the proper invocation command. mdh prompts the user with a colon (:) when it is ready for more input at the command level.
help what write optionshelp - causes mdh to print out a list of all keywords. what - causes mdh to print out the current value of all parameters, and write - asks mdh to attempt writing out the parameters and exiting. options - mdh will print out optional parameters not checked prior to writing.
Keyword #args Hilimit Lolimit Required? nchans 1 16 1 yes odelay 1 256 -256 yes srate 1 768 10 yes cprecis 1 2 1 noThese are relatively straightforward.
nchans - number of channels to digitize srate - sampling rate in Hz. odelay - delay from trigger to stimulus (not presampling, which is specified at averaging time. This value is required because averaging combines the odelay with the requested presampling and produces the appropriate prestimulus presampling interval. Thus, the presampling value is the total prestimulus period. Onset delay is set to zero at this point so no confusion arises further on down the line. So, it is important to fill in odelay with the correct value for further processing and proper calculation of latencies. Negative values for odelay indicate the event precedes the trigger by the absolute value of of the number given ( in milliseconds ). cprecis - epoch precision. Initially one and variable after digitization, it will be removed soon.
subdesc PXM 24-NOV-80 up to 40 chars expdesc a description of the overall experiment
chans 3 odelay 100 srate 384 subdesc P.M. 31-SEPT-80 anencephalic subject expdesc Auditory attention exp. 1 chndesc FZ CZ PZ writeAny command can be entered in any order.
mdh dighead.s03 < dighead.mdh
assuming that "dighead.mdh" is tha name of the file containing
for the mdh program, and the dighead.s03 is the name of
that needs creation.
It is also possible to use edhead, the header editor to change digitization headers. If one wishes to employ this approach, see the summary (manual) entry on edhead.
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