wspectext: Convert 1D image spectra to ascii text spectra

Package: onedspec

Usage

wspectext input output

Parameters

input: Input list of 1D image spectra to be converted. If the image is not one dimensional an warning will be given and the image will be skipped.

output: Output list of ascii text spectra filenames. The list must match the input list.

header = yes: This parameter determines whether or not a descriptive header precedes the wavelength and flux values written to the text file. When header = no, only a two column list of wavelengths and fluxes is output.

wformat = "": The wavelength coordinate output format. If it is undefined the formatting option stored with the WCS in the image header is used. If the WCS formatting option is not defined then a free format is used. See listpixels for a description of the format syntax.

Description

IRAF one dimensional spectra are converted to ascii text files. The text files consist of an optional FITS type header followed by a two column list of wavelengths and flux values. The format of the wavelengths can be set but the flux values are given in free format. This task is a combination of wtextimage and listpixels. The output of this task may be converted back to an image spectrum with the task rspectext.

Spectra which are not in 1D images such as multispec format or long slit may first be converted to 1D images using scopy with format="onedspec".

Examples

1. Write a text file with a header.

cl> wspectext spec001 text001 header+ wformat="%0.2f"
cl> type text001
BITPIX  =                    8  /  8-bit ASCII characters
NAXIS   =                    1  /  Number of Image Dimensions
NAXIS1  =                  100  /  Length of axis
ORIGIN  = 'NOAO-IRAF: WTEXTIMAGE'  /
IRAF-MAX=                   0.  /  Max image pixel (out of date)
IRAF-MIN=                   0.  /  Min image pixel (out of date)
IRAF-B/P=                   32  /  Image bits per pixel
IRAFTYPE= 'REAL FLOATING     '  /  Image datatype
OBJECT  = 'TITLE             '  /
FILENAME= 'TEST              '  /  IRAF filename
FORMAT  = '5G14.7            '  /  Text line format
APNUM1  = '1 1     '
DC-FLAG =                    0
WCSDIM  =                    1
CTYPE1  = 'LINEAR  '
CRVAL1  =                4000.
CRPIX1  =                   1.
CDELT1  =     10.1010101010101
CD1_1   =     10.1010101010101
LTM1_1  =                   1.
WAT0_001= 'system=equispec                                 '
WAT1_001= 'wtype=linear label=Wavelength units=Angstroms   '
END

4000.00  1000.
4010.10  1005.54
4020.20  1011.05
...

2. Write a simple text file with two columns of wavelength and flux.

cl> wspectext spec001 text002 header- wformat="%0.2f"
cl> type text002
4000.00  1000.
4010.10  1005.54
4020.20  1011.05
...

Revisions

WSPECTEXT V2.10.3: This is a new task with this version.