idlastro / FITS I/O: IMLIST

[Source code]

NAME
IMLIST        
PURPOSE
Display pixel values on an image surrounding a specified X,Y center.
EXPLANATION
IMLIST is similar to TVLIST but the center pixel is supplied directly by
the user, rather than being read off of the image display
CALLING SEQUENCE
IMLIST, Image, Xc, Yc, [ TEXTOUT = , DX = , DY = ,WIDTH = ,DESCRIP = ]
INPUTS
Image - Two-dimensional array containing the image 
Xc  -   X pixel value at which to center the display, integer scalar 
Yc -    Y pixel value at which to center the display, integer scalar 
OPTIONAL INPUTS KEYWORDS
TEXTOUT - Scalar number (1-7) or string which determines output device.
         (see TEXTOPEN) The following dev/file is opened for output.
         textout=1       TERMINAL using /more option
         textout=2       TERMINAL without /more option
         textout=3       .prt
         textout=4       laser.tmp
         textout=5       user must open file
         textout=7       same as 3 but text is appended to .prt
                         if file already exists
         textout = filename (default extension of .prt)
 DX     -Integer scalar giving the number of pixels inthe  X direction 
         to be displayed.  If omitted then DX = 18 for byte images, and 
         DX = 14 for integer images.  IMLIST will display REAL data 
         with more significant figures if more room is available to 
         print.  
 DY    - Same as DX, but in Y direction.  If omitted, then DY = DX 
 WIDTH - Integer scalar giving the character width of the output device.
         Default is 80 characters.
 DESCRIP =  Scalar string which will be written as a description over
         the output pixel values.   If DESCRIP is not supplied, and the
         output device specified by TEXTOUT is not a terminal, then the
         user will be prompted for a description.
 OFFSET - 2 element numeric vector giving an offset to apply to the 
         display of the X,Y coordinates of the image (e.g. if the 
         supplied image array is a subarray of a larger image).
OUTPUTS
None.
PROCEDURE
Corresponding region of image is then displayed at
the terminal.   If necessary, IMLIST will divide all pixel values
in a REAL*4 image by a (displayed) factor of 10 to make a pretty format.
SYSTEM VARIABLES
If the keyword TEXTOUT is not supplied, then the non-standard system
variable !TEXTOUT will be read.    (The procedure ASTROLIB is used
to add the non-standard system variable if not already present.)
RESTRICTIONS
IMLIST may not be able to correctly format all pixel values if the
dynamic range of the values near the center pixel is very large
EXAMPLE
Display the pixel values of an image array IM in the vicinity of 254,111
IDL> imlist, IM, 254, 111
PROCEDURES USED
TEXTOPEN, F_FORMAT(), TEXTCLOSE
REVISION HISTORY
Written,    W. Landsman             June, 1991
Added DESCRIP keyword    W. Landsman      December, 1991
Treat LONG image as integer when possible, call TEXTOPEN with /STDOUT
keyword, W. Landsman   April, 1996
Use SYSTIME() instead of !STIME  August 1997
Recognize new integer types, added OFFSET keyword  W. Landsman Jan. 2000
Replace DATATYPE() with size(/TNAME)  W. Landsman Nov. 2001
Handle NAN values in output display W. Landsman June 2004
Use V6.0 notation  W. Landsman April 2011
Remove unnecessary checks if system variable defined W. Landsman May 2016