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

# EOS_PT_DEFBOXREGION

This function defines an area of interest for a point. It returns a point region ID which is used by the EOS_PT_EXTRACTREGION routine to read the fields from a level for those records within the area of interest.The point structure must have a level with both a Longitude and Latitude (or Colatitude) field defined.

## Examples

In this example, we define an area of interest with (opposite) corners at –145 degrees longitude, –15 degrees latitude and –135 degrees longitude, –8 degrees latitude:

cornerlon = dblarr (2)

cornerlat = dblarr (2)

cornerlon[0] = -145.

cornerlat[0] = -15.

cornerlon[1] = -135.

cornerlat[1] = -8.

regionID = EOS_PT_DEFBOXREGION(pointID, cornerlon, cornerlat)

## Syntax

Result = EOS_PT_DEFBOXREGION(pointID, cornerlon, cornerlat)

## Return Value

Returns the point regionID if successful and FAIL (–1) otherwise.

## Arguments

### pointID

Point id (long) returned by EOS_PT_CREATE or EOS_PT_ATTACH.

### cornerlon

Longitude (double) in decimal degrees of box corners (2 element, 1-D array).

### cornerlat

Latitude (double) in decimal degrees of box corners (2 element, 1-D array).

## Keywords

None

## Version History

5.2 | Introduced