# udfGetNbcAuxIds()

Return the nodal boundary condition user auxiliary node numbers.

## Syntax

auxNodeIds = udfGetNbcAuxIds( udfHd ) ;

## Type

AcuSolve User-Defined Nodal Boundary Condition

## Parameters

- udfHd
- The opaque handle (pointer) which was passed to the user function.

## Return Value

- auxNodeIds (Integer*)
- Pointer to two dimensional integer array of user auxiliary node numbers. The first (fast) dimension of the array is the number of nodes, nItems, and the second (slow) dimension is the number of auxiliary nodes, nAuxs.

## Description

This routine returns the array of user auxiliary node numbers. This array is defined by the
auxiliary_nodes parameter of the
NODAL_BOUNDARY_CONDITION command, starting with the second column. For
example,

```
Integer* auxNodeIds ;
Integer usrAuxNode0, usrAuxNode1, usrAuxNode2, node, aux ;
...
udfCheckNbcNumAuxs( udfHd, 3 ) ;
auxNodeIds = udfGetNbcAuxIds( udfHd ) ;
for ( node = 0 ; node < nItems ; node++ ) {
usrAuxNode0 = auxNodeIds[0*nItems+node] ;
usrAuxNode1 = auxNodeIds[1*nItems+node] ;
usrAuxNode2 = auxNodeIds[2*nItems+node] ;
...
}
```

## Errors

- This routine expects a valid udfHd.
- This routine may only be called within a Nodal Boundary Condition user function.
- The corresponding command must have a valid auxiliary_nodes parameter.