# udfGetSdRefCrd()

Return the initial condition nodal coordinates for the nodes in the subdomain.

## Syntax

crd = udfGetSdRefCrd (udfHd) ;

## Type

AcuSolve User-Defined Subdomain Routine

## Parameters

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

## Return Value

- crd (Real*)
- Pointer to two dimensional real array of initial condition nodal coordinates. The first (fast) dimension of the array is the number of nodes, and the second (slow) dimension is three, for the x, y and z coordinates.

## Description

This routine returns the initial condition nodal coordinates for the subdomain. If mesh
displacement is active, the returned coordinates include the initial conditions for the
mesh displacement; that is, the initial deformed configuration. For
example,

```
Real* crd ;
Real x, y, z ;
Integer node, nNodes ;
...
nNodes = udfGetNSdNodes( udfHd ) ;
crd = udfGetSdRefCrd( udfHd ) ;
for ( node = 0 ; node < nNodes ; node++ ) {
x = crd[0*nNodes+node] ;
y = crd[1*nNodes+node] ;
z = crd[2*nNodes+node] ;
...
}
```

## Errors

- This routine expects a valid udfHd.
- This routine may only be called within an external code.