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

# EOS_GD_DEFPROJ

This function defines the GCTP projection and projection parameters of the grid. For GCTP projection information, see the HDF-EOS User’s Guide, Volume 2: Reference Guide provided by NASA.

## Examples

Also see Additional Examples near the bottom of this topic.

### Example 1

In this example, we define a Universal Transverse Mercator (UTM) grid bounded by 54 E - 60 E longitude and 20 N - 30 N latitude - UTM zonecode 40, using default spheroid (Clarke 1866), spherecode = 0:

spherecode = 0

zonecode = 40

status = EOS_GD_DEFPROJ(gridID, 1, zonecode, spherecode, 0)

## Syntax

Result = EOS_GD_DEFPROJ(gridID, projcode, zonecode, spherecode, projparm)

## Return Value

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

## Arguments

### gridID

Grid id (long) returned by EOS_GD_CREATE or EOS_GD_ATTACH.

### projcode

GCTP projection code (long).

### zonecode

GCTP zone code used by UTM projection (long).

### spherecode

GCTP spheroid code (long).

### projparm

GCTP projection parameter array.

## Keywords

None

## Additional Examples

### Example 2

In this example, we define a Polar Stereographic projection of the Northern Hemisphere (True scale at 90 N, 0 Longitude below pole) using the International 1967 spheroid:

spherecode = 3

projparm = lonarr (13)

;Set Long below pole & true scale in DDDMMMSSS.SSS form

projparm[5] = 90000000.00

status = EOS_GD_DEFPROJ(gridID, 6, 0, spherecode, projparm)

### Example 3

Finally, we define a Geographic projection. In this case, neither the zone code, sphere code, or the projection parameters are used:

status = EOS_GD_DEFPROJ(gridID, 0, 0, 0, 0)

## Version History

5.2 | Introduced