late November 1999:

  Variable transformations have been moved from the variable
  labels and given their own panel.  A variety of power transformations
  have been replaced by the Box-Cox family of transformations.  
  Transformation has been given a preparatory stage, too, which
  we're calling "domain adjustment:"  ie, ensure that the data
  you want to transform is within the domain of the transformation
  function.  (We're preparing to break transformation into two
  stages, with permutation, sorting and sphering moved to the
  second stage.)

  1D plotting:  David Scott's 1D ASH (Average Shifted Histogram)
  has been added to the textured dotplot as an alternative 1D plot.
  You can now display these plots either horizontally or vertically

  Axes:  The axes will now behave a bit better -- the labels should
  be smart enough not to draw on top of each other.  In addition,
  the Display menu has one more option, for displaying gridlines
  when in the 1D and 2D plots when axes are shown.

  Identify:  no label will be drawn unless you're within a few
  hundred pixels of some point.

  Linked brushing in the presence of both row groups and nlinkable: 
  few of you will have discovered these options, so even fewer of
  you will know that there were tremendous bugs and limitations
  if you wanted to use them together.  It was even worse if you used
  both of those options in conjunction with either subsetting or
  excluding points.  All this should now work.

  CORBA:  If you go so far as to read the source code, you'll notice
  references to CORBA.  This reflects work done by Duncan Temple
  Lang and Ross Ihaka to make xgobi available from omegahat
  (www.omegahat.org); we expect to test and release this work
  in a few weeks.

late June 1999:
  There are more revisions of the parallel coordinates display -- finally
  it can display labels instead of variable indices.  Long labels will
  be truncated to fit.  If you'd like to supply shorter labels, add them
  to the fname.col file like this:  longname|shortname
  
  Erase brushing has been completely redesigned.  There's no longer an
  erase operation on the brushing panel.  Instead, you brush the points
  you'd like to erase with some chosen glyph/color, and then open the
  "Hide or exclude" tool.  Using that tool, you can hide cases (ie,
  don't draw them) or exclude them (ie, don't draw them <and> don't
  include them in calculations for scaling or sphering or projection
  pursuit.)  If that seems too elaborate for a quick-and-dirty erase,
  just brush them in the background color.

early June 1999:
  There are some revisions in the parallel coordinates display --
  there are now actual parallel coordinates drawn.

  There's a new pair of command line arguments:
   -only n/N : read only a sample of n of N lines
   -only a,n : read only from line a to a+n

  The subset panel has been redesigned in the hope that it
  will be easier to use; its functionality has not changed.

  A couple of new transformations have been added; some of
  these will eventually migrate to a new panel entitled
  "Inference."

  The label of the currently identified point can be captured
  using the 'w' key, and then pasted into another window.

  xgvis changes:
  
  New command line arguments:
    -dims n   specify the dimensionality of the embedding space
    -stepsize x  specify the initial stepsize, a value between 0 and 1
  
March 1999:
  The biggest change in this distribution is the addition
  of the -scatmat command line argument, which instructs
  xgobi to display the input data as a scatterplot matrix,
  which can be linked to other xgobis.

This release (November 1998) has the
following changes:

 Probably the biggest change in this distribution is that
 another program, xgvis, has been included.  xgvis is an
 interactive multidimensional scaling program which has
 its own control panel but uses xgobi as its main data
 display.


This release (March 1998) has the following changes:

 XGobi supports Remote Procedure Calls (RPCs) as a means
 forinterprocess communication (IPC). For example, a link among
 XGobi, ArcView, and XploRe is currently being supported.  See
 http://www.galaxy.gmu.edu/~symanzik/AXX/ for more details.

 There's a new mode on the view menu -- moving points.  This
 is not intended as a way to fix outliers; rather, it's useful
 for graph viewing or manipulating maps or other structures
 that are drawn along with data.

 rgroups, lgroups:  a method for grouping rows so that brushing
 one member causes all other members of the same group to be
 brushed at the same time.  The method is extended to lines, too:
 all lines between points in the same group form a lines group.

This release (October, 1997) has the following changes:

  There is a new command line option, -subset n, that allows
  a subset of the data to be specified:  that is, all the data
  is read in, but an intial subset is used for display.

  The main control panel has been redesigned, so that it
  now uses several menus.  Everything on the View menu
  has been there for a while, while much of what's on the
  Tools menu is new:  Smoothing, jittering, the variable
  and case lists, and some methods for working with missing
  data.

  The case profile has been renamed 'parallel coordinates
  plot,' since that's what it is if all profiles are displayed.

  The file I/O has been gathered from here and there on
  various sub-panels and placed into the File menu --
  unfortunately, not everything there is complete yet.

  The user's manual is quite far behind now, but the help
  files are intended to be current.

The September, 1995 release had the following changes:

  The key additions are the manual controls for the grand
  tour and correlation tour.  Read the help files attached
  to the new menus entitled "Manip" in both Tour and Corr
  mode for instructions.

  On the I/O menu, you'll find two new buttons:  'Clone
  XGobi' and 'Copy XGobi data'.  Each of these starts a
  new XGobi process on the same data, complete with
  brushing.  Again, read the help associated help file for
  details.

  There's one new brushing option on the Options menu,
  'Update brushing continuously.'  When this is off, linked
  brushing changes are only transmitted when you stop
  pressing the mouse button -- it should make it possible
  to perform linked brushing on more cases.

The November, 1994 release had the following changes:

  In Tour mode, several new projection pursuit indices have been
  added.  The indices based on kernel density estimation now show
  the bandwidth in relation to the data on the plot window as it
  is changed with the scrollbar and also while the tour is paused.
  A linked tour has been added -- it's controlled using a menu on
  the tour control panel. It allows comparable sets of data to be
  toured together, supporting, for example, cross-validation.
  Also, linking can be used to compare the performance of two
  projection pursuit indices.

  A correlation tour has been added as a separate plotting mode.

  Control panels have been changed in small ways:  Some controls
  have been removed from the Options panel and organized in a I/O
  panel instead.  The subsetting button has been moved to the
  brushing panel.

  A few more transformations are available on the variable
  transformation menus.

  A new user's manual has been written, but we're not
  able to give this one away; read Readme.doc to learn
  how to buy it.

The April, 1994 release had the following changes:

  It's now possible to read in your data once in ascii, then use
  the options menu to write it back out in binary.  After that,
  the binary file will be read in.  With large data files, there
  is a significant speedup in reading.

  There's now a new input file type, a .nlinkables file.  This
  file contains a single integer specifying the number of rows
  (starting with row 1) that should be used for linked brushing
  and identification.  This makes it possible to link an
  ordinary scatterplot and another sort of plot that uses other
  points to build some sort of decoration -- we are using linked
  brushing between scatterplots and clustering trees, for
  example.  (Call us if you'd like the S function that makes
  that possible.)

  The man page, S function and S help page are new.
  We owe you a new user's manual soon.

The January 1994 release had various bug fixes but little
new functionality.

  For example, there's a workaround for an X bug that made xgobi
  fail when it tried to draw some tens of thousands of circles.

  We have decided to change some of the brushing behavior, and to
  use transient brushing as the default.  A few brushing bugs
  have been repaired -- for instance, transformation during
  brushing wasn't working.

  A bug has been fixed so that now xgobi can handle data when a
  column contains nothing but many replications of the same
  negative number; not many people seem to have encountered that
  one.

  We've changed the appearance of the variable selection panel
  a bit in the hope that it will make it easier for new users
  to realize that they should click on the variable circles.

  And so on; as usual, we don't really document this stuff.

  We've got a bit of new functionality in the wings, and we
  hope to release some of it later this year.

The March 1993 release had the following changes:
 
 * Ability to read .linecolors file. (See data example.)
 * Ability to read .erase file.
 * Ability to write out the data file (See Options menu.)
   Useful for saving transformed or sphered data.
 * Case profile plotting. (See Identify control panel.)
   Especially useful for panel data; write to dfs@research.att.com
   for more information and documentation.
 * Speedups to brushing that make it possible to brush
   many thousands of points. (Thanks for Werner Stuetzle for
   suggestions.)
 * Speedups to identification, again to better handle big
   data sets.
 * Bug fix to S command that enables it once again to accept
   the output of an S command as data input.
 * More glyph types. (See Glyph menu on Brush control panel.)
   This may make old .glyph files no longer suitable; sorry.
 * Data-specific resource files. (See Options menu.)
 * Ability to subset data in three different ways. (See
   Options menu.)  The default method allows you to choose
   a random sample of your data w/o replacement.
 * Beginning to add keyboard controls:  most of the
   buttons in the main panel can now be activated from
   the keyboard.  D or d = Dotplot, X or x = XYPlot, ...
   up through O or o = Options.

 Many extensions to touring (See Tour control panel.)
 See help files for basic information and write to
 dcook@stat.rutgers.edu for more information and documentation.

 * Linked touring. (See Options menu as well as Tour control panel.)
   Useful to compare related data sets or for cross validation.
 * Section tour
 * A menu of interpolation methods is available.
 * Several new projection pursuit indices have been added.
   (See the PP Index menu.)
 * Notations in the code in tour_pp.c tell an adventurous
   user how to add a new projection pursuit index.
 * A set of methods to tailor and interact with the projection
   pursuit window has been added.  (They're on the left side of
   the projection pursuit window.)  In particular, you might
   want to read the help files for 'Return to Bitmp' and 'Record
   Bitmap' if you use the projection pursuit guided tour.

 In the template directory, you will find a heavily commented
 example of the use of XGobi as a function.  This hasn't yet
 been used by anyone, so it's quite rough, but it should be
 a reasonable start.  Please tell us about your experiences
 with these files.

The February 1992 release had these changes:

 * textured dot plotting
 * dotplot cycling
 * an interactive line editing mode
 * ability to read .lines file specifying connected lines
 * line brushing -- by color but not yet by line type; not yet linked
 * a first attempt to allow the plot window to be printed
 * the ability to "delete" and "restore" erased points in brushing
 * an option for maintaining variable continuity between plotting modes

The October 1991 release was re-implemented using the Athena widgets,
written and maintained by the MIT X Consortium, rather than the HP
widgets, which are no longer supported.  It made use of a feature
called 'fallback resources' which make the default resource file
unnecessary -- in fact, the old resource file will inhibit the best
layout, so it should be moved or removed.  In addition, the
partitioning of space among the plot window and the variable selection
panel can now be adjusted interactively.