Dear LinkWinds User or Potential User,
 
The new LinkWinds, version 2.1, is ready for release.  For those
of you who may be unfamiliar with LinkWinds, a brief description
is in the section entitled, "What is LinkWinds?"  Until this
release, LinkWinds has executed only on Silicon Graphics Inc.
(SGI) workstations.  We are also making available an alpha-test
build of LinkWinds which runs on Sun workstations under Solaris
2.4.  It contains the 2-dimensional subset of LinkWinds
applications. The various packages offered are available via
anonymous ftp as described in the section "How to Obtain
LinkWinds."
 
The new features of this version of LinkWinds are described in
the "What's New in LinkWinds" section.  We have extended the
database interfaces to be more robust, and accept more varieties
of data types.  Data formats currently accepted are:
 
1)  Raw binary data in unsigned 1, 2 and 4 byte integers and
4 and 8 byte floating point.
2)  The Hierarchical Data Format (HDF).
3)  The Common Data Format (CDF).
4)  NetCDF.
5)  The Silicon Graphics, Inc. native RGB image format.
6)  Data with Planetary Data System (PDS) headers.
7)  The astrophysics Flexible Image Transport System (FITS).
 
******** How to Obtain LinkWinds ********
 
You can acquire LinkWinds version 2.1 via anonymous ftp from
 
        twinky.jpl.nasa.gov   (IP address:  128.149.102.100)
 
in the /pub/LinkWinds directory.  YOU MUST MAKE THE TRANSFER IN
BINARY MODE.  The files to be taken are 00README.LW and the
appropriate LinkWinds package, as described below.
 
        00README.LW is a text file describing the LinkWinds packages
and text files available.
        INSTALLING describes methods for installing LinkWinds on
your system.
        STARTING explains the basic rules of LinkWinds and how to
get started using it.
        lwx21sgi.tar.Z - the LinkWinds software without
documentation and sample datasets.
        lwx21sun.tar.Z - alpha-test Sun version without
documentation and sample datasets.
        lwx21docs.tar.Z - the LinkWinds documentation.
        sampleDBs.tar.Z - sample datasets to use with LinkWinds.
 
For those who may be unfamiliar with the use of anonymous ftp,
explicit instructions for obtaining the packages are as follows:
 
1.  type                ftp twinky.jpl.nasa.gov
2.  In response to a login request, type "anonymous"
3.  When asked for a password, type your full email address
4.  type                cd pub/LinkWinds
5.  type                binary
6.  type                get 00README.LW
7.  type                get lwx21full.tar.Z (or the package of your
choice)
8.  Type             bye
 
To install the retrieved package on your workstation, place the
file in the directory in which you want to install LinkWinds, and
execute
 
        zcat lwx21.tar.Z | tar xvof -
 
This will create all needed subdirectories with their files.
 
If you already have a previous version of LinkWinds installed,
please consult the instructions in the 00README file.
 
==>  WE ASK THAT IF YOU ACQUIRE LINKWINDS, PLEASE NOTIFY US SO
THAT WE CAN PUT YOU ON OUR MAILING LIST FOR FUTURE CHANGES.
ALSO, PLEASE CONTACT US IF YOU HAVE ANY PROBLEMS WITH THE
INSTALLATION, OR HAVE ANY BUGS TO REPORT OR RECOMMENDATIONS TO
MAKE.  THE LINKWINDS EMAIL ADDRESS IS:
 
        linkwind@apex.jpl.nasa.gov
 
or phone a member of the LinkWinds team at (818) 354-0728.
 
******** What is LinkWinds? ********
 
The Linked Windows Interactive Data System (LinkWinds) is a
visual data exploration system which has served as a testbed
and prototyping environment for a NASA/JPL program of
research into graphical methods for rapidly and
interactively accessing, displaying and analyzing large
multivariate multidisciplinary datasets.  It provides a
variety of functions and services, including interactive 2-
dimensional and 3-dimensional graphical displays of data,
hard copy of graphical displays and text, interactive color
manipulation, animation creation and display, data
subsetting either at the input or output, a journal and
macro capability, context-sensitive help, and network
support for data search and retrieval as well as
collaborative data analysis.  It is an integrated multi-
application execution environment, running under UNIX, with
a full graphical user interface (GUI).  While its GUI is
based upon X Windows, the SGI version of LinkWinds draws
upon the Silicon Graphics Inc. (SGI) IrisGL graphics library
for rendering support.  The Sun alpha-test version currently
uses X Windows exclusively, and will ultimately draw upon
the XGL library. The system has several facilities for
database access and provides for the ingestion of very large
data files in a variety of database formats.
 
******** What's New in LinkWinds ********
 
A more complete discussion of these improvements and new features
is found in the 00README.LW file or the full documentation on the
anonymous ftp.
 
APPLICATIONS:
 
Several new applications have been developed, and many of the
previous applications have been modified.  The new applications
are:
 
o 3D Isosurface Application (Isoview)
This makes a 3D rendering of isovalue surfaces, which may be
lit.  The surfaces are rendered in either rectangular, polar
or spherical coordinates, and may be interactively rotated,
panned, and zoomed.
 
o Light Control Tool (Lights)
Lighting options have been added to all 3D applications,
including Isoview, Plane, Polar and Globe.  The light
control tool allows the user to position the light and
change its properties.
 
o VolumeView
This displays a volumetric rendering of the data set with
transparency at a point dependent upon its data value.  The
user can then view the overall structure throughout a data
set.
 
o Bounding Shape
LinkWinds previously allowed for a region of displayed data
to be bounded with a rectangular box, so that only a subset
of the data points were considered.  The same capability has
been extended to arbitrarily shaped regions.
 
 
DATABASE INTERFACE:
 
Improvements have been made in both the interface with data
formats, and the manner in which the LinkWinds applications
handle data:
 
o Concatenation of data sets.
Often data are stored in multiple files of the same size, which
the user may wish to combine into a single data set.  LinkWinds
now allows the user to concatenate multiple files upon input,
creating a rank 3 data set from a series of 2 dimensional data
files, or a rank 4 data set from a collection of 3 dimensional
files.
 
o Rank 4 data
Previously, data handled by LinkWinds were required to be at most
3-dimensional.  With this release, 4-dimensional data sets may be
dealt with as well.  The data set may be either inherently 4D, or
made from a concatenation of 3D data sets.
 
o Very large data sets
Data sets which are very large compared to the amount of memory
plus swap-space on a workstation can seriously slow performance
and eventually cause cessation of a LinkWinds session.
Interactive subsetting allows the user to limit the region of a
data set ingested using a variety of approaches.
 
o Multiple byte data
Normally, data read into LinkWinds are renormalized and placed
into memory as single byte sized data (256 discrete values).  A
map is maintained relating the byte values to floating point
values.  Previously, data types of more than a single byte were
converted to byte size by binning the data between the minimum
and maximum values read at the input.  The user is now allowed to
(1) change the limits for rebinning the data, and (2) have the
option of using the original data values where appropriate.
 
o Data search and retrieval
Previously, LinkWinds could only use data sets that were
designated in advance.  It now has a file finder to input a data
set from any local file, and a World Wide Web browser to input
data located either locally or on the Internet.  The selected
data sets will be automatically added to the "Data" menu.  In the
case of the web browser, LinkWinds will be launched automatically
if not already executing.
 
******** Disclaimer & Copyright ********
 
LinkWinds is Copyright (C) 1990, 1991,1992,1993,1994,1995 by
California Institute of Technology.  All Rights Reserved.
 
It is provided in the hope that it will be useful, but with
the following limitations:
 
LinkWinds is not to be resold or distributed for sale with
other programs which are for sale.  There is no warranty or
claim of fitness or reliability. The program is distributed
AS IS, and as such neither the authors nor the California
Institute of Technology shall be held liable for any loss of
data, down time, loss of revenue or any other direct or
indirect damage or claims caused by this program.