This function sets the calibration of the specified subdevice so that it is in proper calibration when using the specified channel, range and aref. Depending on the hardware, the calibration settings used may or may not depend on the channel, range, or aref. The file_path parameter can be used to specify the file which contains the calibration information. If file_path is NULL, then comedilib will use a default file location. The calibration information used by this function is generated by the comedi_calibrate program (see its man page).
The functions comedi_parse_calibration_file(), comedi_apply_parsed_calibration(), and comedi_cleanup_calibration() provide the same functionality at a slightly lower level.