IRAF V2.11EXPORT Release Notes


IRAF Group


August 27, 1997


Modifications and additions to IRAF V2.11EXPORT, compiled since the last documented release of IRAF, V2.10.3, are summarized below. V2.11EXPORT is a major release of IRAF and will be available for all supported platforms. These release notes provide a summary of the major changes in V2.11. More detailed technical documentation of all system changes will be found in the notes.v210 and notes.v211 files in the iraf$doc and iraf$local directories.

Things to be aware of or watch out for

Parameter file changes

Since this is a major release we recommend that you do a mkiraf and delete all your old parameter files. You may choose not to do this if you are in the midst of a project and have setups that may be difficult to reproduce. Old IMAGES package parameter files will no longer be recognized, however, because of the package reorganization mentioned below. Generally, old parameter files are merged automatically with any new parameter files if there have been any changes, but if you do have problems you will need to unlearn the task before you can proceed. A list of the parameter file changes appears below and you may wish to check this list to see how this will affect your setups.

The automatic parameter file update/merge mechanism, which is used if you do not initialize your parameters with mkiraf, is based on file date comparisons. If you run IRAF V2.10 after V2.11 has been installed, the file dates on your uparm parameter files will be more recent than the V2.11 installation date. If you then try to run V2.11, the automatic parameter file merge/update will fail due to the file dates. The system only updates personal parameter files which are older than the update date of the system. A mkiraf avoids the problem if you delete your parameter files, causing them to be updated from the system default versions.

Networking change

The “set node = foo” syntax, used to enable remote image display under IRAF networking, has changed. The new syntax requires that an exclamation be appended to the node name as in the example below (this dates back to V2.10.4 so many users will already be familiar with the feature).

cl> set node = "orion!"

Image format change

The internal IRAF image format (.imh images) has changed. V2.11EXPORT can read the old image format but the new image format is not readable by V2.10.4 or earlier versions. This means that you can not easily go from the new IRAF system (V2.11) to an old one (V2.10.4 or earlier) unless you first convert the V2.11 IRAF images to FITS files. All your old V2.10.4 or earlier images are readable by V2.11EXPORT. The benefit is that the new image format is machine independent, slightly more storage efficient, and supports long file pathnames. If it is necessary to be able to read images written by V2.11 with older software, V2.11 can be made to write the old IRAF image format by setting the oifversion environment variable, e.g., “set oifversion = 1” (the default is version 2). See below for details.

FITS kernel

A FITS image kernel is available in V2.11, allowing runtime read and write access to FITS files on disk. There are many related changes to IRAF image i/o and FITS support. More information on the new image kernel, and on the expanded FITS support available in V2.11, is given below.


rfits and wfits have been modified to support multi-extension FITS files. The extension numbering convention used is the same as in the FITS image kernel. As a result, users who read simple FITS files on disk with a command such as “rfits diskfilename 1 foo” will find that this no longer works - instead use “rfits diskfilename 0 foo”. See below for details.

Merged SunOS and Solaris IRAF systems

A single installation of Sun/IRAF will now simultaneously support both SunOS and Solaris (previously separate IRAF distributions were required for each).

Tape access

The “tapecap” mechanism has changed. The system now looks for the filename “tapecap.” followed by the default “tapecap”. : should be the hostname (as used by IRAF networking) of the server hosting the tape drives described by the tapecap file. For example if host “gemini” serves up some tape drives it’s tapecap file is named “tapecap.gemini”. If a server-specific tapecap file is not found the default “tapecap” (on the possibly remote server node) is used. This feature allows a single IRAF installation to be shared by multiple servers.

Default magnitude zero changed

The default APPHOT magnitude zero point has been changed from 26.0 to 25.0 to bring it into agreement with the DAOPHOT package default value and thereby avoid confusion for users who switch back and forth between packages. The affected APPHOT tasks are phot, photpars, polypars, polyphot, qphot, radprof, and wphot. The APPHOTX package in the addon DIGIPHOTX package will retain the old zero point values until IRAF 2.11 is released after which they will be updated.

The default value of the magzero parameter in imexamine was changed from 30.0 to 25.0 for consistency with the DIGIPHOT package.

IMAGES package changes

The IMAGES package has been reorganized by function into the 7 subpackages listed below.

imcoords - Image coordinates package
imfilter - Image filtering package
   imfit - Image fitting package
  imgeom - Image geometric transformation package
 immatch - Image matching and combining package
  imutil - Image utilities package
      tv - Image display utilities package

The new IMAGES package contains a total of 82 tasks, including 26 new tasks from the IMMATCH and VOL external addon packages, 6 existing PROTO package tasks, and 1 existing NOAO.PROTO package task. The undocumented IMAGES package IMDEBUG and its 6 tasks have been deleted from the IMAGES package. User should use the tasks in the ARTDATA package instead.

This reorganization of the IMAGES package should be mostly transparent to the user and not affect any existing scripts, unless you were using any of the 6 deleted tasks. By default, the IMAGES subpackages are automatically loaded when you log in to the CL. Old parameter files will not be recognized since the package names have changed.

Major system changes

New FITS image kernel (FXF)

V2.11 introduces a new image kernel providing runtime access to FITS multi-extension image datafiles. What this means is that IRAF tasks can now read and write FITS images directly at runtime. The native IRAF image format (used by images with the .imh extension), remains the default as it is the most efficient and well-tested format. IMH, FITS, and the other types of images supported by IRAF can be used interchangeably in most IRAF tasks. Although we have extensively tested the new FITS image kernel, it is still evolving, is complex, and still has some bugs. Users should use it with caution. Please let us know of any problems.

Besides support for classical FITS images, the new FITS kernel also supports multi-extension FITS files: several FITS files packed into one large file with a PHU (Primary Header Unit) that contains global header information shared by the other files. Multi-extension FITS files are 0-indexed, with the PHU being 0 and the first image extension (or other data extension) at index 1. If there is no PHU then the first FITS image is 0 and there is no global header.

For further details about the FITS kernel please see the new FITS Kernel User’s Guide by Nelson Zarate.

Changes to the IRAF native image format (OIF)

  • It was necessary to change the IRAF image format to increase the maximum path length for header and pixel files. This made it necessary to change the disk image format, since the old format only allowed 80 characters for the pixel file pathname. The path lengths can now be up to 255 characters.

    Support for two versions of the image and pixel file headers was added. V2.11 will read both the old image format (V1) and the new image format (V2). But the new image format is not readable by older versions of IRAF.

  • Native format IRAF images (OIF type or extension “.imh”) are now machine independent, for example, a PC and a Sun can now access the same images.

  • Support was added for byte swapping pixels. With the machine independent image header, this allows .imh images to be read on any node (integer) or any IEEE-compatible node (floating).

  • Some pointers: “strings foo.imh” (or other tools like the “less” file viewer) can be used at the Unix level to look at the text contained in the new V2 OIF image headers.

IMFORT changes

  • IMFORT was brought up to date to read and write the new V2 “.imh” images. The old V1 format is still supported but new images are written using the new machine independent V2 format by default.

  • Image headers can now be any size (the old IMFORT had a fixed, relatively low, limit on the image header size).

  • The “min_lenuserarea” variable is now supported by IMFORT (since IMFORT is host level the variable must be defined in the host environment). The builtin default header buffer is 64000 chars, which is about 800 card images.

Environment variables

Several new environment variable have been added to the system.

  • The new environment variable imextn determines the image kernels (image file formats) recognized by IRAF and defines the mapping of imagefile extensions to these image formats. A file that does not have an extension listed in imextn may not be recognized as an image by all IRAF tasks. The default value of imextn is as follows:

    imextn = "oif:imh fxf:fits,fit plf:pl qpf:qp stf:hhh,??h"

    IRAF tasks will not recognize a file as an image unless it has an extension (except rfits which will read FITS files on disk that have no extensions). The rename task can be used to add extensions to image files if needed. “imextn” can be redefined (use reset imextn = “new-value”) to modify the mapping of extensions to image types.

    The meaning of the fields of the default “imextn” are as follows. Each substring corresponds to a single kernel. The “xxx:” is the internal name of the image kernel, i.e. “oif”, “fxf”, “plf”, etc. A comma delimited list of the extensions, or extension patterns, associated with that image format follows the colon. For example, for the FITS image kernel, the internal kernel name is “fxf” and the system default file extensions are “.fits” and “.fit”.

    • oif:imh - The original (native) IRAF image format.

    • fxf:fits,fit - The FITS image extension format, which supports classical FITS images as well as multi-extension FITS files.

    • plf:pl - The pixel list format used for compressed pixel masks.

    • qpf:qp - The QPOE image format for event list data (typically X-ray or other high energy data).

    • stf:hhh,??h - The Space Telescope runtime GEIS image format.

    Users can define extensions for the fxf and stf kernels. For example, if you have FITS files on disk that have a .ft extension then you can reset imextn so that IRAF will recognize these image extensions:

    cl> reset imextn="fxf:ft"

    The new .ft extension for the FITS kernel images will now override the default values - the other kernels remain unchanged. “.fits” will no longer be recognized as a FITS file unless you include it in the list of extensions for the “fxf” kernel.

    The first extension given for a kernel defines the default file extension for new images of that type (rather than e.g. the value of imtype, or a builtin default).

    The value of “imextn” is only read once when a process starts up. Hence it is advisable to do a “flpr” (flush process cache) after changing this variable, to force all processes to re-read it.

  • The environment variable imtype defines the default image type for new images created by IRAF. If a file extension is given explicitly when creating a new image then this file extension, in combination with the “imextn” mappings, determines the type of the new image. Otherwise the type is determined by the value of “imtype”. Typical values are “imh” for native IRAF images, or “fits” for FITS images. The internal kernel name documented above for “imextn” can be used instead of a file extension to ensure that the desired image format is used regardless of what extensions are assigned to that type by imextn.

    The default value of imtype is “oif,noinherit” which means that the IRAF native format is the default for all new images, regardless of the type of the input image (i.e. do not “inherit” the input image type). “inherit” was the default in V2.10 and earlier versions of IRAF.

    For example, if you wish to use FITS as the default for new images you can set imtype=fits as follows:

    cl> reset imtype="fits"
    cl> flpr                  % needed before the next task execution

    Assuming “imextn” defines “.fits” as a valid file extension for FITS imagefiles (kernel “fxf”), all new images produced by IRAF will be FITS files with the extension .fits unless some other extension is given explicitly when creating a new image.

    cl> reset imtype = "imh,inherit"

    This example sets the default type for new images to “.imh” for native format images, but enables image type inheritance. By default new images will be of the same type as the input image. For example if a FITS image is being read another FITS image will be output, or if a pixel mask is being read a pixel mask will be created.

    You can override the default output image type specified by imtype by giving an image extension (as defined by imextn) explicitly in the image name, e.g. “pix.imh”, “pix.fits”, “” and so on.

  • A new environment variable called imclobber has been added. The default value is set to no. If imclobber is set to yes, images can and will be overwritten, without warning, when you create new images.

  • The original IRAF image format (OIF) kernel now supports an environment variable oifversion which, if defined, specifies the file version for new OIF images (for example, oifversion=2 produces the new format, or version 2 images). By default the variable is undefined, the builtin OIF default will be in effect, and new-format images will be generated. This variable is provided only for backwards compatibility, e.g., when using V2.11 IRAF with old software which cannot easily be updated.

New intrinsic functions

Two new intrinsic functions were added to the CL, imaccess and defvar. imaccess tests whether an image exists, e.g., (imaccess(“dev$pix”)) or (imaccess(foo.fits[3])). defvar tests whether an environment variable exists, e.g. (defvar(“imextn”)).

System default modifications

  • The default size of the user area (min_lenuserarea) was increased to 64000 (about 800 80 character cards). There was some ambiguity about units for min_lenuserarea; it should be consistently characters now.

  • The maximum number of open IRAF logical files was increased from 128 to

    1. This is good news for imcombine users.

  • Various buffer limits were increased:

    • The IRAF line length was increased from 161 to 1023 characters. One often ran into this lower limit when entering a long list of input image names, for example.

    • CL commands can now be 2047 characters long (the old limit was

        • this is particularly useful for scripts.

    • IRAF file names can now be up to 255 characters long.

    • Expanded file names (pathnames) can be up to 511 characters long.

Libraries added

The Starlink positional astronomy library SLALIB was added to the math package.

Graphics changes

  • SGI Translator change: Modified the header ID string produced by sgi2uapl to be “%!PS”, this is required by certain models of printers.

  • Installed graphcap support for the STSDAS PostScript graphics kernel.

  • The SGI graphics kernel was upgraded with a better roman font, and a new greek font was added. To use the new high-quality greek fonts use the “:raw-latex:`\fG`” escape sequence when you use the “T” keystroke to mark text in a plot, e.g., :raw-latex:`\fGa `:raw-latex:`fRHydra `would produce ” Hydra”. The greek font may also be used in label parameters for tasks like GRAPH, for example

    cl> graph dev$pix xlabel="Wavelength\\fG(A)"

    would produce an Angstrom symbol in parenthesis. The double backslash is necessary to pass the escape string thru the CL. A file containing the mappings for the greek fonts and other special characters can be found at

General changes

  • The GSURFIT package has been updated to include support for the “half” cross terms option useful in computing plate solutions. Tasks that can make use of this feature have been updated although their default behaviors have not changed.

  • The code which computes the CD matrix from CDELT/CROTA was modified. The old code computed the diagonal (scale) terms correctly but the rotation terms were evidently incorrect. The old code was based on the 1988 Hanisch and Wells WCS paper and the new code is based on a more recent paper by Mark Calabretta et al, which supersedes the 1988 representation. The affect of this change should be limited as it only affects rotated images for which CDELT is given but no CD matrix is defined. (V2.10.4p2)

  • Several new celestial coordinate projection functions have been added. Users with IPAC data that use the CAR projection function should now be able to read the image coordinates directly with LISTPIXELS, etc.

New tasks, or old tasks moved to new packages

Task Name      Package                  Function

CCXYMATCH      IMCOORDS         Four new tasks for computing and evaluating
CCMAP                           simple astrometric plate solutions and storing
CCSETWC                         them in the image headers in fits-compatible
CCTRAN                          format.

CCFIND         IMCOORDS         CCFIND locate objects in an image given a
                                celestial coordinate list and the image wcs.

IMCCTRAN       IMCOORDS         Two new tasks for transforming celestial
SKYCTRAN                        coordinate lists and image celestial
                                coordinate systems from one celestial
                                coordinate system to another.

STARFIND       IMCOORDS         STARFIND automatically detects stellar objects
                                in a list of images.

WCSCTRAN       IMCOORDS         A new task for transforming between IRAF image
                                coordinate systems.

WCSEDIT        IMCOORDS         Two unaltered former PROTO package tasks for
WCSRESET                        editing IRAF image coordinate systems.

FRMEDIAN       IMFILTER         Four new tasks for doing circular/elliptical/
FRMODE                          ring image median filtering.

IM3DTRAN       IMGEOM           The former addon VOL package task IM3DTRAN for
                                doing 3D image transposes.

GEOXYTRAN      IMMATCH          A new task for transforming coordinate lists
                                using the results of the GEOMAP task.

IMCENTROID     IMMATCH          Four new tasks for computing matched pixel
SKYXYMATCH                      lists. IMCENTROID is a modified version of the
WCSXYMATCH                      PROTO package task of the same name.

SKYMAP         IMMATCH          Two new tasks for computing geometric
WCSMAP                          transforms using the image coordinate system

IMALIGN        IMMATCH          Three new tasks for doing automated image
SREGISTER                       registration. IMALIGN is a modified version
WREGISTER                       of the PROTO package task of the same name.

WCSCOPY        IMMATCH          A new task for copying the coordinate system
                                of a reference image to a set of input images.

PSFMATCH       IMMATCH          A new task for matching the PSFs of a set of
                                input images to the PSF of a reference image
                                using Fourier techniques.

LINMATCH       IMMATCH          A new task for matching the linear intensity a
                                scale of a set of input images to the
                                intensity scale of a reference image.

IMFUNCTION     IMUTIL           The former PROTO package task for applying a
                                single argument function to an image.

IMJOIN         IMUTIL           The former addon VOL package task for joining
                                same-dimensioned images along a specified

IMREPLACE      IMUTIL           The former PROTO package task IMREPLACE for
                                replacing bad pixels based on their value.

IMTILE         IMUTIL           A modified version of the NOAO.PROTO IRMOSAIC
                                task for tiling same sized 2D images into a
                                single mosaiced image.

EXPORT         DATAIO           Two new tasks from the external IMCNV package
IMPORT                          for exporting IRAF images to binary formats
                                and for importing binary files into IRAF

TEXT2MASK      PROTO            This new task appears in conjunction with a
                                new  pixel mask based version of FIXPIX.

IMEXTENSIONS   PROTO            This task selects and lists image extensions
                                in  files.   Image extensions currently occur
                                in  multi-extension FITS files and multi-group
                                Geiss (STF format) files.

CCDMASK        CCDRED           This new task creates a pixel mask from a
                                CCD image.

AIDPAR         ONEDSPEC         New parameter set for automatic line
                                identification for the tasks AUTOIDENTIFY,
                                IDENTIFY and REIDENTIFY.

AUTOIDENTIFY   ONEDSPEC         A new task to automatically identify lines
                                and fit the dispersion function.

SKYTWEAK       ONEDSPEC         Sky spectra are shifted and scaled to best
                                subtract sky features from data spectra.

TELLURIC       ONEDSPEC         Telluric calibration spectra are shifted and
                                scaled to best divide out telluric features
                                from data spectra.

ASTCALC        ASTUTIL          An astronomical calculator.

ASTRADIUS      ASTUTIL          Finds images within a circle on the sky.

Task and package deletions

CUBE, DUMP, GSUBRAS, MAXMIN, MKIMAGE, MKTEST: These tasks have been superseded by the equivalent tasks in the IMAGES or ARTDATA packages. The functionality of these tasks still exists in the iraf$pkg/images/lib/zzdebug.x file.

REGISTER: This task has been renamed to GREGISTER.


Modifications to old tasks

Grouped by package, a list of modifications to old tasks in IRAF are summarized below. We have included modifications since the V2.10.3 release.



      Minimum and maximum good data value parameters zloreject and zhireject and a verbose option parameter were added.


      The 64 x 64 maximum kernel size limit was removed from these tasks.


    • GEOMAP

      Renamed the output parameter to database for the sake of consistency with other new images tasks.

      Changed the default value of the reject parameter from 0.0 to INDEF.

      Added the transforms parameter. Transforms permits the user to specify the names of the output database records explicitly.

      Added the parameter results. Results permits the user to save a summary of the results including a description of the transform geometry, and a listing of the input coordinates, the fitted coordinates, and the fit residuals.

      Added the fitgeometry parameter. Fitgeometry permits the user to constrain the linear part of the fit to: 1) x and y shifts only, 2) x and y shifts and rotation only, 3) x and y shifts and x and y scale changes only, 4) x and y shifts, rotation, and a scale change only, 5) x and y shifts, rotation, x and y scale changes only, and 5) x and shifts, rotation, skew, and x and y scale changes.


      Renamed the register task gregister to emphasize that it is paired with the geomap task and to avoid confusion with the new registration tasks.


      Renamed the transform parameter to transforms.

      Added the verbose parameter.


      Added the ability to write to a section of an existing image.


      The limit of the number of images that may be combined has been removed. If the number of images exceeds the maximum number of open images permitted then the images are stacked in a single temporary image and then combined with the project option. Note that this will double the amount of diskspace temporarily. There is also a limitation in this case that the bad pixel mask from the first image in the list will be applied to all the images.

      Integer offsets may be determined from the image world coordinate system.

      A combination of ushort and short images now defaults to integer.

      Added support for type ushort images.

      Added a new options for computing offsets using the image wcs.

      Removed the limit on the maximum number of images that can be combined.


      Renamed the images parameter to input, changed the reference parameter mode from hidden to automatic, and reversed the order of the reference and coords parameters.


    • IMEXPR

      Modified the task so that it will accept an image name that looks like a number in the first few characters, but which is really an image name. For example, “123.imh” or “../foo.imh”. The previous version of imexpr was treating any string which looked like a number in the first few characters as a numeric constant. (V2.10.4p2)


      The lower value is now rounded up for integer images so that a range like 5.1-9.9 affects pixels 6-9 instead of 5-9.

    • IMSUM

      Now allows “ushort” data types.

  • TV:


      The bad pixel mask, overlay mask, sample mask, and overlay colors parameters and functionality have been added. The “nsample_lines” parameter is now an “nsample” parameter.

      Bugs in the coordinate system sent to the image display for cursor readback were fixed.

    • IMEDIT

      If xorder or yorder are zero then a median background is computed for the ‘a’ and ‘b’ keys.


      (‘a’ and ‘r’): The fit to the radial profile points now includes both a Gaussian and a Moffat profile. The Moffat profile exponent parameter, beta, may be fixed or left free to be fit.

      (‘a’ and ‘r’): New estimates fo the FWHM were added to the ‘a’ and ‘r’ keys. These include the Moffat profile fit noted above, a direct measurement of the FWHM from the radially binned profile, and a Gaussian or Moffat fit to the radial enclosed flux profile. The output from these keys was modified to include the new information.

      (‘a’ and ‘r’): The direct FWHM may be used to iteratively adjust the fitting radius to lessen the dependence on the initial fitting radius value.

      (‘k’): Added a kimexam parameter set.

      The default value of rimexam.magzero parameter was changed from 30.0 to 25.0 for consistency with the digiphot package.

  • PROTO:

    • FIELDS

      The default value for the lines parameter was changed to an open upper limit.

      Changed the default value of the lines parameter from “1-999” to “1-” so that the upper bound would be open ended.

    • FIXPIX

      This task replaces the old task (now obsolete.ofixpix) and works with the more general pixel mask facilities. It also provides greater flexibility in choosing the interpolation direction.

  • ICFIT used in various tasks:

    • ICFIT

      The :xyshow output was modified to 1) not include colon labels,

      1. print (X, Y, Y fit, Weight) instead of (X, Y fit, Y), and 3) the printed values are those actually used in the fit when using composite points (naverage not 1).


    • MK1DSPEC

      Lorentzian and Voigt profiles were added and the parameters and input line list format were changed. The widths are now FWHM instead of gaussian sigmas.


      The default value of “ranbuf” was changed to zero.


      The default value for the minimum elliptical galaxy axial ratio was changed to 0.3 to cover the range E0-E7 uniformly.


      Now allows ndim=0 to make an dataless header. Now allows ushort pixel type.


    • SETJD

      The checking of the epoch keyword value was improved. Previously if there was a problem with the keyword value (missing or malformed) the task would use the epoch of the observation. Now it is an error if an epoch keyword is specified but the epoch value can’t be determined. Also a leading ‘B’ or ‘J’ is allowed and a warning will be given if the epoch value is unlikely.


      There are new astronomical functions and input/output functions. The command syntax may now use “=” as a delimiter as well as the whitespace.

      A new parameter “update” allows protecting images and accessing read-only images for the purpose of calculating and printing quantities.

      The special variable name “$I” has the value of the image name, $D the current date, and $T the current time.

      The case of no image name creates and deletes a temporary image so the task can be used purely as a calculator (but see astcalc).



      The bad pixel fixing was modified to allow use of pixel masks, images, or the text file description. Bad pixel masks are the desired description and use of text files is only supported for backward compatibility. Note that support for the trimmed or untrimmed conversion from text files has been eliminated.

      Line-by-line overscan/prescan subtraction is now provided with three simple algorithms.


      The limit of the number of images that may be combined has been removed. If the number of images exceeds the maximum number of open images permitted then the images are stacked in a single temporary image and then combined with the project option. Note that this will double the amount of diskspace temporarily. There is also a limitation in this case that the bad pixel mask from the first image in the list will be applied to all the images.

      Integer offsets may be determined from the image world coordinate system.

      Fixed a bug where a variable was improperly used for two different purposes causing the algorithm to fail. This also affected IMCOMBINE and SCOMBINE. See bug 316 for details. (V2.10.4p2)


      The output bad pixel data accidentally included some extra fields making it incorrect to use the file directly with BADPIXIMAGE.
      The extra diagnostic fields were removed. For details, see bug 311 in the buglog. (V2.10.4p2)


      The dispersion units are now determined from a user parameter, the coordinate list, or the database entry.

  • IMRED Spectral Packages:


      A sky alignment option was added.

      The aperture identification can new be taken from image header keywords.

      The initial arc line identifications is done with the automatic line identification algorithm.


      The initial arc line identifications is done with the automatic line identification algorithm.


    Support for the Sloan Sky Survey was added by allowing multifiber reductions with up to 500 fibers with non-linear dispersions. (V2.10.4p2)

    • BPLOT

      Fixed a general problem in BPLOT and SLIST that caused a segmentation violation error. See buglog 312 for details. (V2.10.4p2)


      Modified to include lorentzian and voigt profiles. The parameters and positions file format have changed in this version. A new parameter controls the number of Monte-Carlo samples used in the error estimates.


      The dispersion units are now determined from a user parameter, the coordinate list, or the database entry. A new key, ‘e’, has been added to add features from a line list without doing any fits. This is like the ‘l’ but without the automatic fitting before and after adding new features.

      A new key, ‘b’, has been added to apply an automatic line identification algorithm.

      The ‘x’ key has been changed to use the automatic line identification algorithm. The allows finding much larger shifts.

      The match parameter may now be specified either in user coordinates or in pixels. The default is now 3 pixels.

      The default threshold value has been changed to 0.


      A new parameter, “search”, was added to specify a search radius for the automatic line identification algorithm.

      The “nlost” parameter now also applies when not tracing; i.e. it will issue a warning and not record a solution if the specified number of features is lost when reidentifying against a specific reference spectrum as is done with multispec data.

      The task will now work with only a warning if the reference image is absent; i.e. it is possible to reidentify given only the database.

      The addfeatures function will now add features before a fit if there are no reference database features. Previously features could only be added after an initial fit using the reference features and, so, required the reference database to contain features for reidentification. This new feature is useful if one wants to uses a dispersion function from one type of calibration but wants to add features for a different kind of calibration.


      This task has been modified to allow use of image header keywords as done in the APEXTRACT package.

    • SARITH

      Previously both w1 and w2 had to be specified to select a range to be used. Now if only one is specified the second endpoint defaults to the first or last pixel.

      The noise band in multispec data is only copied from the primary spectrum and not modified. This is a kludge until the noise is handled properly.

      Fixed a problem in SARITH and SCOPY where a segmentation error occurred when a wavelength range was specified in the reverse sense of the data and without rebinning. See buglog 323 for details. (V2.10.4p2)

    • SBANDS

      Fixed a problem in SBANDS that caused a segmentation violation when the number of input bandpasses was greater than 10. See buglog 298 for details. (V2.10.4p2)

    • SCOPY

      Previously both w1 and w2 had to be specified to select a range to copy. Now if only one is specified the second endpoint defaults to the first or last pixel.


      The scale and offset parameters may now be a value, a filename, or and image header keyword.

      The ‘f’ key was added to toggle between world and logical pixel coordinates.

    • SPLOT

      The profile fitting and deblending was expanded to include lorentzian and voigt profiles. A new parameter controls the number of Monte-Carlo samples used in the error estimates.


      The task now automatically senses the presence of a header.



      The “apertures” parameter can be used to select apertures for resizing, recentering, tracing, and extraction. This parameter name was previously used for selecting apertures in the recentering algorithm. The new parameter name for this is now “aprecenter”.


      The “nsubaps” parameter now allows onedspec and echelle output formats. The echelle format is appropriate for treating each subaperture as a full echelle extraction.

    • APALL

      The aperture ID table information may now be contained in the image header under the keywords SLFIBnnn.

    • APSUM

      The dispersion axis parameter was moved to purely a package parameter.

      As a final step when computing a weighted/cleaned spectrum the total fluxes from the weighted spectrum and the simple unweighted spectrum (excluding any deviant and saturated pixels) are computed and a “bias” factor of the ratio of the two fluxes is multiplied into the weighted spectrum and the sigma estimate. This makes the total fluxes the same. In this version the bias factor is recorded in the logfile if one is kept. Also a check is made for unusual bias factors. If the two fluxes disagree by more than a factor of two a warning is given on the standard output and the logfile with the individual total fluxes as well as the bias factor. If the bias factor is negative a warning is also given and no bias factor is applied. In the previous version a negative (inverted) spectrum would result.

  • RV:


      These tasks now work in the units of the input spectra.

    • FXCOR

      The input spectra are converted to Angstroms for the crosscorrelation and analysis. Thus the velocities will be correctly computed regardless of the units of the input spectra.



      A major bug in the DAOFIND task centering code that affects the computed x and y positions was fixed. Users should refer to bug log entry number 332 for details. (V2.10.4p2)

      A new roundness statistic was added to the DAOFIND output to bring the task into conformance with standalone DAOPHOT II. The new statistic is sensitive to and tries to eliminate detected objects which are significantly elongated in directions other than 0, 90, 180, and 270 degrees. The original roundness statistic is stored in the ground column, the new one in the sround column. The same default roundness limits apply to both statistics. (V2.10.4p2)


      Added a new parameter “mergerad” to the DAOPARS parameter set. Mergerad permits the user to control the merging process. If mergerad is INDEF (the default setting) the default merging radius is used. If mergerad is 0 object merging is turned off altogether. Otherwise the user can set the merging radius to a specific value. Mergerad is used by the nstar and allstar tasks, but their default behavior is unchanged. (V2.10.4p2)

      Changed the name of the “critovlap” parameter to “critsnratio” to avoid confusion with the meaning of the parameter especially with regard the mergerad parameter. The behavior of the parameter is unchanged. (V2.10.4p2)

Parameter file changes

The parameter file changes below are for modifications between V2.10.4 and V2.11. For a list of parameter file changes between V2.10.3 and V2.10.4 see the file iraf/v210/params.v2104.Z in the IRAF FTP archives.

In the tables below each parameter change is identified with one of the following codes followed by task_name.parameter_name and the description of the change.

  • n = new parameter

  • c = changed/modified parameter

  • d = deleted parameter


n  display.nsample: replaces nsample_lines
d  display.nsample_lines: replaced by nsample
n  display.bpmask: specify a bad pixel mask
n  display.bpdisplay: specify display mode for bad pixel mask
n  display.bpcolors: specify overlay colors for bad pixel mask
n  display.overlay: specify an overlay mask
n  display.ocolors: specify overlay colors for overlay mask
n  display.zmask: specify a sample mask for the zscale calculation
c  imedit.xorder: now allows a value of zero for median background
c  imedit.yorder: now allows a value of zero for median background
n  rimexam.fittype: specify a profile type to fit - default is now moffat
n  rimexam.iterations: specify number of iterations to adjust fitting radius
n  rimexam.beta: specify beta value for moffat fitting
c  rimexam.buffer: default value changed from 1 to 5
c  rimexam.width: default value changed from 2 to 5
c  rimexam.magzero: default value changed from 30 to 25
n  wcslab.overplot: specify overplotting


n  wfits.fextn: extension to append to output disk FITS filename - default is
n  wfits.extensions: write all images to a single FITS file ? - default is no
n  wfits.global_hdr: prepend a global header to the FITS extensions - default
     is yes


n  fmedian.zloreject: good data minimum
n  fmedian.zhireject: good data maximum
n  fmedian.verbose: verbose option
n  fmode.zloreject: good data minimum
n  fmode.zhireject: good data maximum
n  fmode.verbose: verbose option
n  median.zloreject: good data minimum
n  median.zhireject: good data maximum
n  median.verbose: verbose option
n  mode.zloreject: good data minimum
n  mode.zhireject: good data maximum
n  mode.verbose: verbose option
n  geomap.transforms: list of record names
n  geomap.results: results summary file
n  geomap.fitgeometry: fitting geometry
d  geomap.output: renamed to database
c  geomap.reject: changed from 0.0 to INDEF
n  [g]register.verbose: verbose option
d  [g]register.transform: renamed to transfo
n  geotran.verbose: verbose option
d  geotran.transform: renamed to transforms
c  imcombine.offsets: now allows specifying "wcs" to compute offsets from WCS
d  imalign.images: renamed to input
c  imalign.reference: went from hidden to auto
c  imalign.coords: reversed places with reference
d  imcentroid.images: renamed to input
c  imcentroid.reference: went from hidden to auto
c  imcentroid.coords: reversed places with reference
n  imheader.imlist: default image names


n  graph.ltypes: specify the line types
n  graph.colors: specify the colors


n  fixpix.masks: new version specifies bad pixel masks
n  fixpix.linterp: specify mask values for line interpolation
n  fixpix.cinterp: specify mask values for column interpolation
n  fixpix.pixels: list pixels that are modified
d  fixpix.badpixels: new version does not use bad pixel region description
c  fields.lines: default value changed from "1-9999" to "1-"


n  mk1dspec.profile: define the profile type
n  mk1dspec.gfwhm: replaces sigma for gaussian profile width
n  mk1dspec.lfwhm: width for lorentzian profile
c  artdata.randbuf: default value changed from 1000 to 0.
c  mkpattern.ndim: allows a value of 0 for a dataless header.
c  mkpattern.pixtype: allows ushort.
c default value changed to 0.3.
d  mk1dspec.sigma: replaced by gfwhm


n  rvcorrect.keywpars: added to define keywords used
n  asthedit.prompt: used for new calculator option
n  asthedit.update: update the header
n  asthedit.oldstyle: to allow backward compatibility

APEXTRACT, IMRED spectral packages:

n  apnoise.apertures: select apertures to be used
n  apfit.apertures: select apertures to be used
n  apedit.apertures: select apertures to be used
n  apfind.apertures: select apertures to be used
n  apnormalize.apertures: select apertures to be used
n  apscatter.apertures: select apertures to be used
n  apsum.apertures: select apertures to be used
n  aptrace.apertures: select apertures to be used
n  apresize.apertures: select apertures to be used
n  apmask.apertures: select apertures to be used
n  apflatten.apertures: select apertures to be used
n  aprecenter.apertures: select apertures to be used
n  aprecenter.aprecenter: was what was previously the apertures parameter
n  apall.apertures: select apertures to be used
n  apall.aprecenter: was what was previously the apertures parameter


n  doargus.crval: for automatic line identifications
n  doargus.crdelt: for automatic line identifications
n  doargus.skyalign: night sky alignment option
n  dohydra.crval: for automatic line identifications
n  dohydra.crdelt: for automatic line identifications
n  dohydra.skyalign: night sky alignment option
n  dofibers.crval: for automatic line identifications
n  dofibers.crdelt: for automatic line identifications
n  dofibers.skyalign: night sky alignment option
n  do3fiber.crval: for automatic line identifications
n  do3fiber.crdelt: for automatic line identifications


c  params.match: default value changed to -3 (3 pixels instead of Angstroms)
c  sparams.match: default value changed to -3 (3 pixels instead of Angs)

ONEDSPEC, IMRED spectral packages:

d  fitprofs.sigma: replaced by gfwhm
d  fitprofs.function: replaced by profile
d  fitprofs.fitsigmas: replaced by fitgfwhm
d  rspectext.header: removed since the task now senses the header information

ONEDSPEC, LONGSLIT, IMRED spectral packages:

n  identify.units: specify the desired units for the dispersion function
n  identify.crval: for automatic line identifications
n  identify.crdelt: for automatic line identifications
n  identify.aidpars: parameter set for automatic line identifications
c  identify.match: default value changed to -3 (3 pixels instead of Angstroms)
c  identify.threshold: default value changed from 10 to 0.
c  reidentify.match: default value changed to -3 (3 pixels instead of Angs)
c  reidentify.threshold: default value changed from 10 to 0.
n  reidentify.crval: for automatic line identifications
n  reidentify.crdelt: for automatic line identifications
n  reidentify.aidpars: parameter set for automatic line identifications
n specify a search radius for the automatic line
      identification algorithm
n  ecidentify.units: specify the desired units for the dispersion function
n  fitprofs.profile: define the profile type
n  fitprofs.gfwhm: replaces sigma for gaussian profile width
n  fitprofs.lfwhm: width for lorentzian profile
n  fitprofs.fitgfwhm: replaces fitsigmas
n  fitprofs.fitlfwhm: select whether to fit lorentzian profile widths
n  fitprofs.nerrsample: allows control of the error calculation accuracy
n  splot.nerrsample: allows control of the error calculation accuracy


c  ccdproc.fixfile: this now specifies a bad pixel mask
c  combine.offsets: now allows specifying "wcs" to compute from WCS


n  rvcorrect.par: Added the KEYWPARS pset declaration


c  daopars.critsnratio: critical S/N ratio for group membership - changed
      the name only from critovlap (V2.10.4p2)
n  daopars.mergerad: critical object merging radius in scale units