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

# EOS_SW_EXTRACTREGION

This function reads data into the data buffer from the subsetted region. Only complete crosstracks are extracted. If the external_mode flag is set to (1) then the geolocation fields and the data field can be in different swaths. If set to (0), then these fields must be in the same swath structure.

Note: Array ordering of variables used or returned by this routine changed in IDL 5.5. Programs written for versions of this routine prior to IDL 5.5 may need to be modified to work correctly with the current version.

## Examples

In this example, we read data within the subsetted region defined in EOS_SW_DEFBOXREGION from the Spectra field. Both the geolocation fields and the Spectra data field are in the same swath.

status = EOS_SW_EXTRACTREGION(EOS_SW_id, regionID, 0, "Spectra",$

datbuf)

## Syntax

Result = EOS_SW_EXTRACTREGION(swathID, regionID, fieldname, external_mode, buffer)

## Return Value

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

## Arguments

### swathID

Swath id (long) returned by EOS_SW_CREATE or EOS_SW_ATTACH.

### regionID

Region id (long) returned by EOS_SW_DEFBOXREGION.

### fieldname

Field to subset (string).

### external_mode

External geolocation mode (long).

### buffer

A named variable that will contain the data buffer.

## Keywords

None

## Version History

5.2 | Introduced