# udfGetSdDataDim()

Return the dimension of a data variable.

## Syntax

dataDim = udfGetSdDataDim( udfHd, dataName ) ;

## Type

AcuSolve User-Defined Subdomain Routine

## Parameters

- udfHd
- The opaque handle (pointer) which was passed to the user function.
- dataName (integer)
- Symbolic name corresponding to the data index.
- UDF_SD_VELOCITY
- Velocity.
- UDF_SD_ACCELERATION
- Acceleration.
- UDF_SD_PRESSURE
- Pressure.
- UDF_SD_TEMPERATURE
- Temperature.
- UDF_SD_SPECIES
- Species.
- UDF_SD_EDDY_VISCOSITY
- Turbulence eddy viscosity.
- UDF_SD_KINETIC_ENERGY
- Turbulence kinetic energy.
- UDF_SD_EDDY_FREQUENCY
- Turbulence eddy frequency.
- UDF_SD_MESH_DISPLACEMENT
- Mesh displacement.
- UDF_SD_MESH_VELOCITY
- Mesh velocity.
- UDF_SD_TURBULENCE_Y
- Distance to nearest turbulence wall.
- UDF_SD_TURBULENCE_YPLUS
- Turbulence y+ based on distance to nearest turbulence wall and shear at that wall.

## Return Value

- dataDim (integer)
- Dimension of the data variable.

## Description

```
Integer dataDim ;
...
dataDim = udfGetSdDataDim( udfHd, UDF_SD_VELOCITY ) ;
```

## Errors

- This routine expects a valid udfHd.
- This routine may only be called within an external code.
- dataName must be one of the values given above.
- The subdomain must contain the equation associated with the data variable.