<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >comedi_get_softcal_converter</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE=" Comedi " HREF="index.html"><LINK REL="UP" TITLE=" Comedi Function Reference " HREF="x4629.html#FUNCTIONREFERENCE"><LINK REL="PREVIOUS" TITLE="comedi_get_hardcal_converter" HREF="r6585.html"><LINK REL="NEXT" TITLE=" Glossary " HREF="g6677.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Comedi: The <SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >Control and Measurement Device Interface</I ></SPAN > handbook </TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="r6585.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="g6677.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="FUNC-REF-COMEDI-GET-SOFTCAL-CONVERTER" ></A >comedi_get_softcal_converter</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN6635" ></A ><H2 >Name</H2 >comedi_get_softcal_converter -- get converter for software-calibrated subdevice</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN6638" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><P ></P ><A NAME="AEN6639" ></A ><PRE CLASS="FUNCSYNOPSISINFO" >#include <comedilib.h></PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int comedi_get_softcal_converter</CODE >(unsigned subdevice, unsigned channel, unsigned range, enum comedi_conversion_direction direction, const comedi_calibration_t *parsed_calibration, comedi_polynomial_t *converter);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN6656" ></A ><H2 > Status </H2 ><P > alpha </P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN6659" ></A ><H2 > Description </H2 ><P >comedi_get_softcal_converter() initializes <CODE CLASS="PARAMETER" >converter</CODE > so it can be passed to either comedi_to_physical() or comedi_from_physical(). The <CODE CLASS="PARAMETER" >converter</CODE > parameter can then be used to convert data from the specified <CODE CLASS="PARAMETER" >subdevice</CODE >, <CODE CLASS="PARAMETER" >channel</CODE >, and <CODE CLASS="PARAMETER" >range</CODE >. The <CODE CLASS="PARAMETER" >direction</CODE > parameter specifies whether <CODE CLASS="PARAMETER" >converter</CODE > will be passed to comedi_to_physical() or comedi_from_physical(). The <CODE CLASS="PARAMETER" >parsed_calibration</CODE > 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.</P ><P >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.</P ><P >Whether or not the result of this function actually depends on the <CODE CLASS="PARAMETER" >channel</CODE > 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.</P ><P >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. </P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN6674" ></A ><H2 > Return value </H2 ><P >Zero on success or -1 on failure. </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="r6585.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="g6677.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >comedi_get_hardcal_converter</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="x4629.html#FUNCTIONREFERENCE" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Glossary</TD ></TR ></TABLE ></DIV ></BODY ></HTML >