ATC: fix_modify AtC output boundary_integral

# fix_modify AtC output boundary_integral

## syntax

fix_modify AtC output boundary_integral [field] faceset [name]

- field (string) : name of hardy field
- name (string) : name of faceset

## examples

`fix_modify AtC output boundary_integral stress faceset loop1`

## description

Calculates a surface integral of the given field dotted with the outward normal of the faces and puts output in the "GLOBALS" file

## restrictions

Must be used with the hardy/field type of AtC fix ( see fix atc command )

## related

## default

none