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

# HDF_VG_LONE

The HDF_VG_LONE function returns an array containing the IDs of all VGroups in an HDF file that are not contained in another VGroup.

## Examples

X=HDF_VG_LONE(fid)

IF X(0) EQ-1 THEN $

PRINT, "No Lone VGroups" ELSE PRINT, "Lone VGroups:", X

## Syntax

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

## Return Value

Returns the IDs of lone VGroups or returns -1 if there are no lone VGroups,.

## Arguments

### FileHandle

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

## Keywords

### MAXSIZE

The maximum number of groups to return (the default is to return all lone VGroups). For example, to return no more than 12 VGroups, use the command:

X = HDF_VG_LONE(fid, MAX=12)

## Version History

4.0 | Introduced