NDF2GASP - Converts a two-dimensional NDF into a GASP image

Description:

This application converts a two-dimensional NDF into the GAlaxy Surface Photometry (GASP) package's format. See the "Notes" for the details of the conversion.

Usage:

ndf2gasp in out [fillbad]

Parameters:

IN = NDF (Read)

The input NDF data structure. The suggested default is the current NDF if one exists, otherwise it is the current value.

FILLBAD = _INTEGER (Read)

The value used to replace bad pixels in the NDF's data array before it is copied to the GASP file. The value must be in the range of signed words ($-$32768 to 32767). A null value (!) means no replacements are to be made. This parameter is ignored if there are no bad values. [!]

OUT = FILENAME (Write)

The name of the output GASP image. Two files are produced with the same name but different extensions. The ".dat" file contains the data array, and ".hdr" is the associated header file that specifies the dimensions of the image. The suggested default is the current value.

Examples:

ndf2gasp abell1367 a1367

Converts an NDF called abell1367 into the GASP image comprising the pixel file a1367.dat and the header file a1367.hdr. If there are any bad values present they are copied verbatim to the GASP image.

ndf2gasp ngc253 ngc253 fillbad=-1

Converts the NDF called ngc253 to a GASP image comprising the pixel file ngc253.dat and the header file ngc253.hdr. Any bad values in the data array are replaced by minus one.

Notes:

The rules for the conversion are as follows:

• The NDF data array is copied to the ".dat" file.

• The dimensions of the NDF data array is written to the ".hdr" header file.

• All other NDF components are ignored.

Related Applications :

CONVERT: GASP2NDF.

References :

GASP documentation (MUD/66).

Implementation Status:

• The GASP image produced has by definition type SIGNED WORD. There is type conversion of the data array to this type.

• Bad values may arise due to type conversion. These too are substituted by the (non-null) value of FILLBAD.

• For an NDF with an odd number of columns, the last column from the GASP image is trimmed.