Featured Contents:

• Mathematica Version 2.1
• 1992 Mathematica Conferences
• MathLink
• Reducing Memory Usage

About MathUser

MathUser is published by Wolfram Research to provide timely news and information about Mathematica to registered Mathematica users.

This issue includes some important announcements for Mathematica users, as well as tips for getting the best out of Mathematica.

Feedback about this issue of MathUser and suggestions for future issues will be gratefully received at the address below.

Copyright Wolfram Research, Inc., 1992. MathUser (ISSN 1062-7030) is published quarterly by Wolfram Research, Inc.; 100 Trade Center Drive, Champaign, IL 61820-7237, USA; email: mathuser@wri.com.

Mathematica is a registered trademark and MathLink and MathSource are trademarks of Wolfram Research, Inc. Mathematica is not associated with Mathematica Inc., Mathematica Policy Research, Inc., or MathTech, Inc. All other product names mentioned are trademarks of their producers.

Mathematica Version 2.1

The development of Mathematica is a continuing process, with the release of Version 2.0 representing a major landmark. Soon the results of still further Mathematica development will be available as Version 2.1.

Subscribers to the Mathematica Plus program will automatically receive this version over the next few months.

There are many significant enhancements in Version 2.1, although all Version 2.0 Mathematica programs and Notebooks should run without change in Version 2.1.

In all, over 50 built-in Mathematica functions have been enhanced in one way or another for Version 2.1, and 10 new application packages have been added. The documentation for Version 2.1 includes a complete Guide to Standard Mathematica Packages.

On Unix platforms, the MathLink system for connecting Mathematica to external programs has been enhanced and extended, and new documentation for it has been added. Complete MathLink libraries are included to allow you to create external C programs that communicate with Mathematica.

MathLink is also now available on the Macintosh. It allows you to write programs that communicate with Mathematica on Macintosh and other computers. Both the MPW and THINK C compilers are supported. (See the article 'MathLink Developer's Kit on the Macintosh' later in this newsletter for further information.)

On all Unix and PC systems, "thin version" installation is now supported, substantially reducing the amount of memory needed to start up Mathematica. (See the article 'Tips for Reducing Memory Usage' later in this newsletter for more details.)

On the Macintosh, new features include support for QuickTime. Animations created in Mathematica can be converted to QuickTime, and QuickTime material from Mathematica or other programs can be included in Mathematica Notebooks.

Finally, under Microsoft Windows, Mathematica provides full support for Windows 3.1. By making use of enhanced memory management and other features of Windows 3.1, Mathematica 2.1 runs much more efficiently and reliably than under Windows 3.0.

Mathematica 2.1 on all systems comes with a special automatic installation procedure, which allows you to install Version 2.1 in parallel with Version 2.0 as quickly as possible. On all systems, passwords for Version 2.1 are pre-assigned by Wolfram Research before shipment as upgrades to registered users.

For information on Version 2.1 availability, contact the Wolfram Research Sales department.

Among the enhancements affecting all computer systems are:

• Memory usage in storage of Mathematica expressions has been reduced by 10% to 50%, allowing calculations to be done with smaller amounts of RAM.

• Many algorithms have been enhanced to be more robust and to run faster.

• Graphics have been speeded up; ContourPlot in particular is up to five times faster in Version 2.1, and generates smoother contour lines.

• New Mathematica packages have been added in such areas as nonlinear fitting, binary file manipulation, Dirac delta functions, and sound synthesis.

The Mathematica Plus Program

The Mathematica Plus program gives users access to Wolfram Research's continuing research and development on Mathematica. All subscribers to Mathematica Plus receive at least two updates to Mathematica every year, including new and faster Mathematica features, new Mathematica packages and documentation, as well as support for upgrades to computer operating systems and other system software.

Version 2.1 is the first upgrade being made available to Mathematica 2.0 owners through the Mathematica Plus program. NeXT users should note that Mathematica Plus is available even when they received Mathematica 2.0 bundled with their computer system.

To subscribe to Mathematica Plus, call us today at 1-800-441-MATH. Please have your Mathematica license number as well as credit card or PO number ready when you call.

1992 Mathematica Conferences

North America: Boston, May 27-31

Now in its third year, the annual North American Mathematica Conference provides a unique opportunity to find out how Mathematica is being used and how to get the most out of the system for yourself. Over a thousand users at all levels are expected to attend. Features of the conference include:

• Tutorials at elementary, intermediate, and advanced levels

• Invited lectures on applications of Mathematica from entomology to financial analysis

• Contributed lectures and teaching lab sessions

• Forums and Mathematica problem-solving clinics

A new feature this year is the addition of Mathematica courses held on May 27 and 28, immediately preceding the main conference. The courses span elementary and advanced topics.

As at previous Mathematica conferences, there will be computers of many kinds available for hands-on interaction with Mathematica.

Pre-registration deadline: May 1, 1992

Deadline for conference submissions: April 15, 1992

Europe: Rotterdam, September 2-4

The first European Mathematica Conference, held at the World Trade Center in Rotterdam, Netherlands, will be this year's major focus for Mathematica in Europe. As with the North American conference, it will include tutorials, invited lectures, forums, and problem-solving clinics. There will also be a large number of contributed lectures from people using Mathematica throughout Europe.

Pre-registration deadline: August 1, 1992

Deadline for conference submissions: July 15, 1992

For information on the Mathematica conferences, telephone Wolfram Research at 217-398-0700, send a fax to 217-398-0747, or send electronic mail to conference@wri.com.

Educational Discount Programs

Wolfram Research has announced that it will continue its highly successful Educational Grant Program for educators who are setting up Mathematica-based teaching laboratories.

Wolfram Research now also offers a Site License program, intended for large-volume departmental and campus Mathematica purchases.

For information on the range of educational discounts available, contact an educational account executive at 1-800-441-MATH, or send email to education@wri.com.

Student Version Available

The Student Version of Mathematica is now available for Macintosh, MS-DOS, and Microsoft Windows. This is a full function version of Mathematica, though with less documentation and support than the professional version, and without support for numeric coprocessors. The Student Version is available from bookstores and campus resellers to registered college and highschool students. Suggested U.S. list price: $175. Suggested international list price: $199.

Tips for Reducing Memory Usage

The basic code of Mathematica is built to be able to handle calculations of any size. But in practice the size of calculation you can do on a particular computer system is always limited by the amount of memory available on that system. Particularly on smaller computers, therefore, it is often important to be able to minimize the amount of memory that Mathematica uses. Here are a few tips about how to do this.

• Starting with 2.0, versions of Mathematica on most computer systems allow you at installation time to set up a "thin" kernel. Using a thin kernel in no way affects the functionality of the system, but it makes the system use less memory at the cost of increased initialization time for some operations such as sophisticated symbolic integration. The thin kernel works by not including the code for these kinds of operations in Mathematica when it starts up, and loading this code only when it is explicitly needed. Of course, if this code is loaded, the amount of memory needed will be exactly the same as if the thin version had not been used.

• In Version 2.1, the function Share (given with no arguments) will reduce the amount of memory that is used internally. If your Mathematica session involves many large expressions or if you notice that your memory usage has increased you should execute Share. This may take some time to run but can result in large amounts of memory being freed up. Share returns the number of bytes of memory that are no longer being used.

• Version 2.1 includes many internal enhancements to reduce memory usage. Compare ByteCount[expr] for various expressions in Version 2.0 and Version 2.1 and you will see memory space reductions of between 10% and 50%.

• You should remember that Mathematica saves all the output results you get during a session, thereby often using a substantial amount of memory. You can discard these results by typing the Mathematica commands: Unprotect[Out]; Clear[Out]; Protect[Out].

Some Bugs and Fixes

In a software system as large as Mathematica there are inevitably bugs. Here is a list of some bugs in Mathematica 2.0 recently reported by users or detected by our continuing testing process.

• ComplexExpand gives incorrect results for certain complex conjugates and functions involving branch cuts. This has been fixed in Version 2.1.

• Certain definite integrals of quadratic exponentials and a few related integrals return incorrect answers. The correction is included in an extensive revision of Mathematica's definite integration capabilities in Version 2.1.

• Some PostScript interpreters incorrectly render Mathematica-generated PostScript for the Raster and DensityGraphics objects. Mathematica 2.1 generates additional PostScript to avoid these problems.

• Macintosh PowerBook computers can go into their slow clock rate "rest mode" during long kernel computations. Version 2.1 automatically avoids this problem.

We consider software quality assurance an important part of the Mathematica development process. At this point, we have assembled something over half a million test examples of Mathematica. If you have examples that you feel are good tests for Mathematica, we encourage you to submit them to tests@wri.com. The appropriate format for all tests is Test[input, output].

MathLink Developer's Kit on the Macintosh

MathLink, the Mathematica external communication protocol, is now available for the Macintosh. Previously available only on Unix versions of Mathematica, MathLink now allows Macintosh users the ability to write external programs that communicate with Mathematica on Macintosh and other computers. MathLink on the Macintosh supports both THINK C and MPW C compilers. With MathLink, Mathematica can communicate with commercial applications as well custom programs, allowing data to be exchanged in both directions.

To get MathLink for the Macintosh, registered users of Mathematica 2.1 for the Macintosh can order the free MathLink Developer's Kit. The kit includes MathLink libraries, example files, and documentation. An order form for the MathLink Developer's Kit is included with each copy of Mathematica Version 2.1 for the Macintosh.

New Mathematica Workstation Licensing

Starting in February 1992, Wolfram Research has added new options for licensing Mathematica on workstation systems.

There are now two basic kinds of Mathematica workstation licenses:

• Single-Machine Licenses: Mathematica is locked to a particular CPU.

• Network Licenses: Mathematica can float across a network, being used on one binary-compatible CPU at a time.

All machines covered by a network license must have access to the same file server.

The Mathematica network license manager can be configured in several ways. It allows, for example, certain machines or certain users to be given priority in running Mathematica.

For further information on license options, contact the Wolfram Research Sales department.

Mathematica Applications Wanted

We are always very interested to hear how Mathematica is being used. We are particularly interested in seeing papers that are based on calculations done with Mathematica. So far, we have received nearly a thousand such papers, spanning a remarkable range of application areas. If you have a paper that has used Mathematica, we would very much like to receive a copy of it. Send it via postal mail to Librarian, Wolfram Research. We will happily send you a free Mathematica T-shirt in return.

MathSource

An exciting new service will soon be available to Mathematica users. MathSource is an electronic repository of Mathematica material that can be accessed via electronic mail and computer networks.

MathSource is available free of charge to all Mathematica users. To get started using MathSource, send a single-line email message of

help intro

mathsource@wri.com

The same help command can be used to obtain information about submitting new material for publication on MathSource. Issuing the command

help submit

Why Email Is the Best Way to Get Technical Support

Electronic mail is the best way to get technical support for Mathematica. It's true, we can answer many questions by phone. But when you submit a technical question by email, you can formulate the problem more clearly before you contact us, and we can often give you better answers. Here are some of the advantages of email-based technical support.

Email lets us give your question to the engineer best suited to answer it, and it is easy to forward email questions to our development staff.

Email allows you to submit your technical support questions any time of the day or night, seven days a week, regardless of the hours that the Wolfram Research Technical Support staff is on duty.

You can send copies of your Mathematica sessions by email. We can pipe your message right into Mathematica to duplicate your problem.

Perhaps best of all, we can send you pieces of Mathematica code. We have numerous solutions for common problems that can be sent by email.

Although email is the best way to get technical support for all types of questions, it is about the only way to get good technical support when it comes to these:

• Questions about Mathematica syntax

• MathLink examples

• Long questions, or questions with more than one point

• Large excerpts of Mathematica code (>10 lines)

So, the next time you need technical support for Mathematica, try sending your question by email. We'll be able to serve you better. The email address for Mathematica technical support is support@wri.com.

Mathematica Miscellanea

The poster developed to commemorate the release of Mathematica Version 2 features a graphic of 5 intersecting tetrahedra generated in Mathematica. Copies of this full-color poster (20" x 29") are available at a price of $5 while supplies last to all registered users of Mathematica Version 2.

To order your poster, send payment to Poster Offer, Wolfram Research, or send electronic mail to miscellanea@wri.com with your VISA or Master Card credit number. Please give your name as it appears on your registration card, and your Mathematica license number.

Other Mathematica miscellenea still in stock include:

• T-shirts: several designs, L and XL sizes. $10

• Zeta function posters: 6 foot long Mathematica plot of the Riemann zeta function, with explanatory and historical text. $5

• Mathematica mugs: black stoneware with aqua Mathematica logo, graphics. $5

Mathematica Versions Available

The following new versions of Mathematica have recently been released:

• Hewlett-Packard 700

• NEC EWS 4800

• Silicon Graphics Indigo Series

Computer system	Operating system versions currently supported
Apple Macintosh	System Software 6.0.7 or later, or A/UX; System 7.0 compatible
Microsoft Windows	MS-DOS Version 3.0 or later; Microsoft Windows 3.0 or later
MS-DOS	MS-DOS Version 3.0 or later
CONVEX	ConvexOS 8.0 or later
Data General	DG-UX 4.2 or later
Digital Equipment	VAX/VMS 5.0 or later; RISC ULTRIX 2.3 or later
Hewlett-Packard	HP-UX 7.0 or later
Apollo	Domain/OS SR 10.1 or later
IBM RISC System/6000	AIX 3.1 or later
MIPS Systems	RISC/os (UMIPS) 4.5 or later
NEC	EWS-UX/V (Rel. 4.0), NEC Release 4.1 Rev 06 or later
NeXT	NeXT 0S 2.1 or later
Silicon Graphics	IRIX 3.3 or later
Sony	For NEWS-based systems, requires NEWS 3.3C or later; For RISC NEWS-based systems, requires NEWS 4.00R
Sun-3 and SPARC	SunOS 3.5 or later

Questions & Answers

*What can I do if I get a Windows Unrecoverable Application Error (UAE)?

Running Mathematica under Windows 3.0 sometimes results in a UAE. Although these errors may seem to occur randomly, they are usually related to problems with memory management under Windows. We encourage upgrading to Windows 3.1, which has an improved virtual memory system. It is also helpful to allocate more memory (see next question).

*How can I change the amount of memory Mathematica for Windows uses?

When the Windows kernel is loaded, the available memory decreases by an amount greater than the size of the kernel file. This is because, in addition to the space required to load the executable, the kernel requests extra memory for Mathematica calculations. You can increase or decrease this amount by editing the line ExtraPages=2000 (just change the number) in MATH.INI. Each page is 4 KB of RAM.

*How can Mathematica graphics be imported to other software?

One of the most common exchange formats for graphics information is Encapsulated PostScript (EPS). This is PostScript with a few other "comments" added. These extra comments are understood by the software program receiving the graphic to help it incorporate the picture into the document.

The Display function saves a description of the graphic in a file with Mathematica's extended PS (many functions are not part of standard PS). Many of these extensions are not understood by enclosing software programs, so the file must be "fixed".

MS-DOS and Unix:

In[1]:= Plot[ Sin[x], {x, 0, 2 Pi} ]

Out[1]= -Graphics-

In[2]:= Display[ "mathps", % ]

Out[2]= -Graphics-

MS-DOS versions of Mathematica include a utility called PRINTPS.exe, which is a program that can take Mathematica's PS and convert it to EPS. This will be replaced by a program called RASTERPS in a future release.

C:\MATH> printps -eps realps.eps -fonts C:\MATH\FONTS mathps

Unix versions of Mathematica accomplish this with a utility called psfix.

% psfix -epsf < mathps > realps.eps

Macintosh:

• Issue a Plot command and select the graphics cell by clicking the cell bracket or anywhere in the contents of the cell.

• Choose Copy from the Edit menu.

• Choose Convert Clipboard... from the Edit menu.

• Select the Encapsulated PostScript radio button.

• Click the Save in File button to name and save the new file.

The file can then be imported to other software programs, like WordPerfect on the PC (use Alt-F9, Figure, Create, Filename), Microsoft Word on the Macintosh (make sure you set the Style to PostScript), or TeX documents on workstations. Note that some programs will not recognize the fact that the file is EPS because certain "optional" elements are not included.

Opportunities at Wolfram Research

Wolfram Research is expanding and we are looking for outstanding people to join the team. At present, there are positions open in language development and application package development, as well as in technical writing and technical marketing.

We are also planning to start a new program of visiting research and development staff. Intended primarily for academics, both at postdoctoral and senior levels, the program will bring experienced Mathematica users to Wolfram Research for periods of between one month and one year to contribute to the Mathematica development effort. Particularly of interest are individuals who can help develop new application areas for Mathematica.

Send applications for all positions to Personnel department, Wolfram Research (resumes@wri.com). Wolfram Research is an affirmative action/equal opportunity employer.

How to Contact Us by Email
(All addresses given are for Internet)

info@wri.co	General and sales information
service@wri.com	Customer service
register@wri.com	User registration
support@wri.com	Technical support
conference@wri.com	Mathematica conferences
info-europe@wri.com	European Mathematica information
support@wri.com	Mathematica bug reports
suggestions@wri.com	Mathematica bug reports
feedback@wri.com	Feedback about uses of Mathematica
mathuser@wri.com	This newsletter

Here are the personal email addresses of some Wolfram Research managers:

jstein@wri.com	Jim Steinbacher (sales manager)
valiquet@wri.com	Chris Valiquet (order administration manager)
pkatula@wri.com	Paul Katula (technical support manager)
pc@wri.com	Prem Chawla (chief operating officer)
sw@wri.com	Stephen Wolfram (president)