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       comedi_get_softcal_converter  -  get  converter for software-calibrated


       #include <comedilib.h>

       int comedi_get_softcal_converter (unsigned subdevice, unsigned channel,
       unsigned   range,  enum  comedi_conversion_direction  direction,  const
       comedi_calibration_t      *parsed_calibration,      comedi_polynomial_t




       comedi_get_softcal_converter()  initializes  converter  so  it  can  be
       passed to either comedi_to_physical() or  comedi_from_physical().   The
       converter parameter can then be used to convert data from the specified
       subdevice, channel,  and  range.   The  direction  parameter  specifies
       whether   converter   will   be   passed   to  comedi_to_physical()  or
       comedi_from_physical().  The parsed_calibration parameter contains  the
       software  calibration  values  for  your device, and may be obtained by
       calling comedi_parse_calibration_file() on a calibration file generated
       by the comedi_soft_calibrate program.

       This function is only useful for boards that perform their calibrations
       in software on the host computer.  A subdevice will advertise the  fact
       that  it depends on a software calibration with the SDF_SOFT_CALIBRATED
       subdevice flag.

       Whether or not the result of this  function  actually  depends  on  the
       channel  parameter  is  hardware dependent.  For example, a multiplexed
       analog input will typically use the  same  calibration  for  all  input
       channels.  Analog outputs will typically use different calibrations for
       each output channel.

       Software calibrations are  implemented  as  polynomials  (up  to  third
       order).   Since  the  inverse  of  polynomials of order higher than one
       can’t be represented exactly as another polynomial, you may not be able
       to get converters for the "reverse" direction.  For example, you may be
       able to get a converter for an analog input in  the  COMEDI_TO_PHYSICAL
       direction, but not in the COMEDI_FROM_PHYSICAL direction.


       Zero on success or -1 on failure.

                                28 October 2007COMEDI_GET_SOFTCAL_CONVERTER(3)