Routines (alphabetical) > Routines: H > HDF-EOS Routines > EOS_PT_DEFLINKAGE

# EOS_PT_DEFLINKAGE

This function defines the linkfield between two levels. This field must be defined in both levels.

## Examples

In this example, we define the ID field as the link between the two levels defined previously in the EOS_PT_DEFLEVEL function:

status = EOS_PT_DEFLINKAGE(pointID2, "Desc-Loc", $

"Observations", "ID")

## Syntax

Result = EOS_PT_DEFLINKAGE(pointID, parent, child, linkfield)

## Return Value

Returns SUCCEED (0) if successful and FAIL (–1) otherwise.

## Arguments

### pointID

Point id (long) returned by EOS_PT_CREATE or EOS_PT_ATTACH.

### parent

Name (string) of parent level.

### child

Name (string) of child level.

### linkfield

Name (string) of common linkfield.

## Keywords

None

## Version History

5.2 | Introduced