---
name: "comedi_from_phys"
section: "3"
platform: "linux"
package: "libcomedi-dev"
version: "0.11.0+5-1.3+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/comedi_from_phys"
---

# comedi\_from\_phys(3)

convert physical units to sample

## NAME

comedi\_from\_phys - convert physical units to sample

## SYNOPSIS

```
#include <comedilib.h>
```

**lsampl\_t comedi\_from\_phys(double** *data***, comedi\_range \*** *range***, lsampl\_t** *maxdata***);**

## DESCRIPTION

Converts parameter *data* given in physical units (**double**) into sample values (**lsampl\_t**, between 0 and maxdata). The parameter *range* represents the conversion information to use, and the parameter *maxdata* represents the maximum possible data value for the channel that the data will be written to. The mapping between physical units and raw data is linear and assumes that the converter has ideal characteristics.

Conversion is not affected by out-of-range behavior. Out-of-range data parameters are silently truncated to the range 0 to *maxdata*.

## AUTHORS

**David Schleef** \<ds@schleef.org\>

Author.

**Frank Mori Hess** \<fmhess@users.sourceforge.net\>

Author.

**Herman Bruyninckx** \<Herman.Bruyninckx@mech.kuleuven.ac.be\>

Author.

**Bernd Porr** \<tech@linux-usb-daq.co.uk\>

Author.

**Ian Abbott** \<abbotti@mev.co.uk\>

Author.

**Éric Piel** \<piel@delmic.com\>

Author.

## COPYRIGHT

Copyright © 1998-2003 David Schleef\
 Copyright © 2001-2003, 2005, 2008 Frank Mori Hess\
 Copyright © 2002-2003 Herman Bruyninckx\
 Copyright © 2012 Bernd Porr\
 Copyright © 2012 Ian Abbott\
 Copyright © 2012, 2015 Éric Piel\

This document is part of Comedilib. In the context of this document, the term "source code" as defined by the license is interpreted as the XML source.

This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, version 2.1 of the License.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.