# fix_modify AtC sample_frequency command

## Syntax

    fix_modify <AtC fixID> sample_frequency <freq>

-   AtC fixID = ID of [fix atc](fix_atc) instance
-   sample_frequency = name of the AtC sub-command
-   freq = frequency to sample fields in number of steps

## Examples

``` LAMMPS
fix_modify AtC sample_frequency 10
```

## Description

Specifies a frequency at which fields are computed for the case where
time filters are being applied.

## Restrictions

Must be used with [fix atc hardy](fix_atc) and is only relevant when
time filters are being used.

## Related AtC commands

-   [fix_modify AtC command overview](atc_fix_modify)

## Default

None.