Routines (alphabetical) > Routines: H > HDF Routines > HDF_VD_FDEFINE

# HDF_VD_FDEFINE

The HDF_VD_FDEFINE procedure adds a new field specification for a VData in an HDF file. HDF_VD_FDEFINE can only be used for a new VData.

## Examples

HDF_VD_FDEFINE, vid, 'VEL', /DOUBLE, ORDER=3

## Syntax

HDF_VD_FDEFINE, VData, Fieldname [, /BYTE | , /DOUBLE | , /FLOAT | , /INT | , /LONG] [, ORDER=value] [, /UINT] [, /ULONG]

## Arguments

### VData

The VData handle returned by a previous call to HDF_VD_ATTACH.

### Fieldname

A string containing the new field name.

## Keywords

### BYTE

Set this keyword to indicate that the field will contain 8-bit unsigned integer data.

### DOUBLE

Set this keyword to indicate that the field will contain 64-bit floating point data.

### FLOAT

Set this keyword to indicate that the field will contain 32-bit floating point data.

### INT

Set this keyword to indicate that the field will contain 16-bit integer data.

### LONG

Set this keyword to indicate that the field will contain 32-bit integer data.

### ORDER

This keyword specifies the number of distinct components in the new field. Compound variables have an order greater than 1. The default order is 1.

### UINT

Set this keyword to indicate that the field will contain 16-bit unsigned integer data.

### ULONG

Set this keyword to indicate that the field will contain 32-bit unsigned integer data.

## Version History

4.0 | Introduced