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

# HDF_VD_LONE

The HDF_VD_LONE function returns an array containing all VDatas in an HDF file that are not contained in another VData.

## Examples

X = HDF_VD_LONE(fid)

IF N_ELEMENTS(X) EQ 0 THEN $

PRINT, 'No Lone VDatas' ELSE PRINT, 'Lone VDatas:', X

## Syntax

Result = HDF_VD_LONE( FileHandle [, MAXSIZE=value] )

## Return Value

Returns any lone VDatas within an array. If there are no lone VDatas, HDF_VD_LONE returns -1.

## Arguments

### FileHandle

The HDF file handle returned from a previous call to HDF_OPEN.

## Keywords

### MAXSIZE

The maximum number of groups to be returned (the default is to return all known lone VDatas). For example, to return only the first 12 groups:

X = HDF_VD_LONE(fid, MAX=12)

## Version History

4.0 | Introduced