edf_set_transducer — Sets the transducer of signal edfsignal ("AgAgCl cup electrodes", etc.).
edf_set_transducer(path, edfsignal, transducer)
This function is optional for every signal and can be called only after opening a file in writemode and before the first sample write action.
path is a string containing the path and name of the file
transducer is a pointer to a string containing the transducer text of the signal edfsignal.