Important Changes for Release 1.8

SAOtng is an evolving (some would say oscillating) system: we try to respond to user needs as quickly as possible. The following changes have been initiated by user feedback:

Display of FITS image extensions and binary tables

SAOtng now can display FITS image extensions, FITS binary tables and raw event files. See Loading an Image for more information. (NB: If you maintain a PFILES directory, please delete any old fitsextract.par file found there, since this version of the fitsextract program has new parameters.)

SAOtng now can apply filters to binary tables and event files.

See Event Filtering for more information.

Display of compressed FITS and WWW FITS files

SAOtng now can display compressed FITS files by automatically decompressing them on the fly. It also can retrieve files over the Web. See Loading an Image for more information.

Support for IMAGE_PATH environment variable

SAOtng now will search for image files in directories specified by the IMAGE_PATH environment variable. See Loading an Image for more information.

Fixing marker parameters

SAOtng now allows you to "fix" a variety of parameters for specified markers so that they cannot be moved, resized, etc. See Fixing and Freeing Region Markers for more information.

Enhanced scaling support

SAOtng now can support a different scale algorithm for each display frame. Also the Scale menu option allows you to choose different ways of setting the scaling min and max values for a given frame. See The Scale Menu for more information.

Changes to tiling

In tiling mode, previous versions of SAOtng automatically changed frames as the mouse moved between frames. This feature annoyed users, so we disabled it. Frames now are changed by means of the Frame menu, even in tiling mode. The auto-switching of tiled frames can be turned back on by means of a button on the Control Panel.

Changes to the zoom xpa access point

We have split the zoom public access point, which previously controlled zoom, pan, flip, and autoflip into 4 separate public access points called "zoom", "pan", "flip", and "autoflip". See the SAOtng XPA List for more information.

Changes to auto blocking

When blocking is set to auto in the Images menu, we now restrict the valid block factors to be powers of 2. This change was necessary in order to ensure accuracy in the placement of region markers. To remove this restriction, set the environment variable SAOTNG_RESTRICT to "false".

Marker keystrokes (obscure)

Because of conflicts with IRAF, the i,e,s,b keystrokes within a marker (used to change a marker to "include", "exclude", "source", or "background", respectively) have been changed to ctrl-i, ctrl-e, ctrl-s, and ctrl-b.

IRAF-related changes

SAOtng now sets up the IRAF socket and unix pipe parameters to match the IRAF defaults. The fifo parameters still are set to "none", however.

A slight modification has been made to the command line for extracting FITS images from IRAF images. We hope this change will alleviate the (passive) "Write to IPC with no reader" error messages that sometimes were printed out as an IRAF image was being processed.

Internal changes

Our FITS support (e.g. fitsextract) was based on an old saord/FITS library that only understood primary FITS images. It has been replaced with the newer saord/fitsy library that also handles FITS image extensions and binary tables. If you were using the old FITS library, please contact us for information about how to convert to the new and much nicer library.

Netscape 4.0.x problems

Please note that versions 4.0.3 and 4.0.4 of Netscape ignore the -ncols switch that limits the number of colors hogged by the program. Therefore, when you are running Netscape 4.0.x, SAOtng will not be able to allocate colors from the public colormap and will be forced to switch to a private colormap. There is no work-around for this anti-social behavior on the part of Netscape. (Note that Netscape 3.x works properly.)

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Last Updated July 8, 1998