NAME

xrfits -- Convert FITS data to IRAF IMAGE or TABLE files

USAGE

xrfits input output oldirafname

DESCRIPTION

The xrfits task reads standard FITS IMAGE and table data --from either disk or tape--and converts them to IRAF files (either IMAGE(imh) or TABLE(tab)). This task calls the TABLES strfits task, with parameters defaulted for X-RAY data.

This task can read three types of extensions -- TABLE, IMAGE-IUE and BINTABLE. The BINTABLE extension is limited to 1 element per cell on a table.

The xrfits task can also read files in the IEEE standard format. FITS data written in IEEE standard will be converted to images in the local floating point format. The IEEE standard is noted in the FITS header by a negative BITPIX value.

The FITS long blocks option is supported---up to 10 blocks of 2,880 bytes. If SIMPLE=F, a warning message is printed to the standard output.

PARAMETERS

input [string]

The FITS data source. This is either a template describing a list of disk files, or a tape file specification of the form "mt*[n]", where "mt" indicates a magnetic tape device, "*" represents a density, and "[n]" is the tape file number to be read. If the tape file number is specified, only that file is converted. If the tape device name is given without a tape file number, e.g., "mta" or "mtb800", then the files specified by the file_list parameter will be read from the tape. If you want to use an input tape you will need to allocate it before running strfits, this can be done with the allocate command, for example, "allocate mta".

output [string]

The IRAF file that is to be created from the FITS data. This can be a single file name, a list file (i.e. @flis) or the null file (i.e. ). When handling multiple files, this parameter will be used as a prefix and the file number will be appended. If only a single file is being converted, the file will be named as specified. For example, reading files 1 and 3 from a FITS tape and using a file name of data for this parameter will produce the files data001 and data003. If the disk or tape files contain more than one table per file then this parameter will be used as a root name and a sequential number will be appended to it, e.g., "tab01.tab", "tab02.tab" and "tab03.tab" will be created when 3 tables are contained in one file.

(oldirafname = no) [boolean]

Restore the image to disk using the IRAFNAME parameter in the FITS header? If FITS tables are present, the program will try to restore the table to disk using the filename defined by the EXTNAME parameter in the standard extension FITS parameter header. If output parameter is NULL (i.e. ) or it does not have an extension the filename extension will be taken from the imtype cl variable; but if this imtype is not defined the extension will be set to imh. If the output parameter has a root and an extension, this extension takes precedence over the imtype value.

file_list [string]

The files to be read from a tape. This string can consist of any sequence of file numbers separated by at least one comma or dash. A comma separates individual file numbers, whereas a dash specifies a range of files. For example the string "1,2,3-5,8-6" will convert tape files 1 through 8.

(long_header = no) [boolean]

Print the full FITS header on the standard output?

(short_header = yes) [boolean]

Print shortened headers on the standard output? If short_header = yes, the task will print one line information with the following columns:

		IRAFNAME  Output image name
		DIMENSION Image dimensionality
		BP        Output image bits/pixel
		DATE      Creation date
		OBJECT    Content of OBJECT FITS keyword

(datatype = "default") [string]

This is the data type for the IRAF image file, which may be a different data type than the FITS image file. The allowed values are "unsigned" (16bits), "short", "integer", "real", and "double". Truncation problems may occur if an inappropriate data type is specified. Incorrect data types or null strings in this parameter will cause the default to be used. The default data type is determined by the minimum size required for the input pixel values. If the bscale and bzero parameters in the FITS header are undefined, or if bscale=1.0 and bzero=0.0, then the data type will be either short or long--otherwise it will be real.

(st = no) [boolean]

Convert an extra dimension FITS file to a ST/GEIS multigroup image file? To do this you should have written the FITS file with the task stwfits. For more details see Description above.

(scale = yes) [boolean]

Scale the data based on the values of bscale and bzero? If scale = no, then the integers are read directly from the tape, otherwise the program checks the values of bscale and bzero. If these numbers are not 1.0 and 0.0, respectively, the program scales the data before output.

(blank = 0.0) [real]

The IRAF image value of a blank pixel.

(offset = 0) [integer]

This parameter specifies the offset to be used in assigning a name to the resulting GEIS file. For example, if 'offset = 100', iraf_file = "fits", and file_list = "1-3", the output file names will be fits101, fits102 and fits103 rather than fits001, fits002, and fits003.

EXAMPLES

1. Convert a set of FITS files on tape to a set of IRAF image files, allowing the program to select the output data type. Blanks will be set to zero.

	xd> xrfits mtb1600 images filelist="1-99"

2. Convert a set of FITS files on disk to a set of IRAF images

	fi> xrfits fits* images

3. Convert a set of FITS files directly to IRAF images without scaling.

	fi> strfits mtb1600  images filelist="1-999" scal-

BUGS

The program cannot yet read images that have excessively long lines because the image I/O has memory allocation restrictions. Blank pixels are counted and set to a user-determined value, but are not flagged in the image header. The program CANNOT produce an output QPOE file.

SEE ALSO

strfits,xwfits,fits2qp,stwfits, allocate