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## Xact - an unsung hero

By Manfred Agne © February 2002

Recently, I discovered that my favourite commercial OS/2 application, Xact, has never been reviewed in any VOICE newsletter! This may be due to the fact that the current version (7.0) is the first version after many years that is also available in English. The last English version before that was 3.2, which went GA in 1994. Versions 4 to 6 were only available in German.

## What it is:

Xact is a chart publishing application with vector graphics functions which is made by Scilab, a German company based in Hamburg. If you have ever used Origin (a Windows application), Xact does roughly the same thing, but better :-) Unfortunately, Xact is not a cheap application, prices range from US-$ 499 for a single user version to US-$ 3499 for the 5-user network license of Xact Pro, and if you are a student, there are also educational versions with a rebate. You'll get a CD with the OS/2-, Win16- and Win32 Version, and a printed handbook which is also on the CD as a PDF-file. The prices are similar to those of Origin, only slightly better. However, SciLab's service is outstanding, and Xact is the most stable and probably the most useful software that I have ever bought. Unlike many other commercial OS/2 applications, Xact is not a ported Windows product. If I remember correctly, it was originally developed for Atari, and when that platform died, SciLab started developing Xact for OS/2.

I became interested in Xact in 1994, when I was working on my PhD thesis. At the time, version 3.2 was out, and although the price was pretty tough for me, I went for the student version. It came in a big box, with a brief manual, a photocopied sheet saying that the extensive manual formerly delivered had been abandoned because nobody read it anyway, and a few 3.5" floppy disks - three, if I remember correctly. Over the years, I went through versions 4, 5, and 6, and upgraded from the student version to the full version. I'll explain why:

## The intended use

As I already said, Xact is a chart publishing program. If you are a scientist and want to (need to) fit curves to your experimental data, Xact is for you. If your job involves the frequent presentations of financial data, Xact helps you do your work. If you need bar charts, pie charts, scatterplots, or any of the numerous other ways of presenting and analyzing numerical data, Xact is just the thing to buy. Xact Pro even does CMYK separation, which comes quite handy if you are producing for professional print publications, and it also works with shapefiles (eg. vector maps). All versions of Xact can generate and use graphics templates: If you need to do the same presentation each and every month, only with ever varying figures (eg. the monthly sales report of your company), you could generate a template with your specific layout and presentation method, including the company logo, special fonts, background bitmap, whatever you like, and use the month's figures to generate the actual graph from the template. Since Xact for OS/2 comes with a REXX interface, you can also write your own script which completes the presentation for you.

Xact imports data in the most common file formats - from CSV (comma separated value) files and several other spreadsheet formats (ASCII, DIF, WKS, WK1, WK3, XLF and DBF), the data are read into a "table". If there are too many data points, it is also possible to perform automatic data reduction during data import. Then, you will usually perform some operations in the table, define various columns as "X-", "Y-", or "Z-data", and select the plot to be generated. The plot can either be a graphical representation, or it can again be a table - if you are doing TEX, this is probably the most convenient way to generate a LATEX table! The available choice of data graphs seems to cover even the most extravagant wishes. There are 12 categories (Line, Ribbon, Bar, and Pie charts, Tables, Stock charts, 3D-Line, Contour , Surface , Profile, Special, and Polar plots) with a total of 79 graphs, each having further options. After selection of the appropriate options, Xact draws the graph as a vector graphic which can be scaled and modified in a number of ways. For example, a double-click on any part of the graph will usually pop-up a settings notebook with a wealth of options - colors, fonts, linewidth, visibility, scaling, almost everything can be modified. However, even the default settings usually create a quite nice and usable graph, so there's no need to get too involved, unless you want to. The result can then be saved in Xact's internal vector graphics format, or it can be exported in the most commonly used vector graphics formats (including EPS, MET and WMF). If desired, Xact also exports the result to bitmap format files (BMP, TIF, and PCX).

Currently, Xact is available for OS/2, 16-bit Windows, and 32-bit Windows. There are demo versions of the three products in German and English available at http://www.scilab.de, along with a 170 page PDF manual which is compatible with Acrobat Reader 3 for OS/2. On OS/2, the Win9x version requires ODIN, but if this is installed, all three versions of Xact install and run (and uninstall) just fine on Warp and eCS. Not that I would see much reason to try this - the OS/2 version has the same functionality as the Win-based versions, and the data format is the same across all platforms.

Note that the bottom right window on the screenshot shows the Win9x version - my ODIN installation is configured to use the OS/2 window buttons rather than the Win style buttons. However, you can tell that it is the Win version by comparing the checkboxes in the lower part of the window to those in the left window, which is the native OS/2 program running under eComStation.

Xact also has a pretty good and well-documented REXX interface. It doesn't have the tools to modify or add to Xact's own GUI, but all the charting and drawing tools seem to be available via REXX, and Xact comes with some examples. It is also possible to have Xact generate a bitmap image from the output. Therefore, you could probably use Xact's REXX interface to periodically generate and update a dataplot for a website - the monthly sales figures, the seismographic data from the volcano in your backyard, or a scatter plot from your latest proton-antiproton collision experiment ;-) You name it, Xact does it.

## Xacts second face

Let's face it, this looks very much like a pretty specialized application, and it is. However, there is another side to the program. Xact not only generates vector graphics, it also has a fairly complete set of vector drawing tools. Admittedly, it is not a Corel Draw for OS/2, but it is the bread-and-butter graphics application that I use for my 2D-graphics needs; 3D I usually do with POVRAY. In fact, from day one, this was the most useful (and surprising) feature in Xact, and it is the reason why I still use it almost every day.

The vertical button bar on the left has the drawing tools; as indicated by the small arrows, most buttons have further buttons attached to them which can be accessed by clicking on the button, and dragging to the right while keeping the left mouse button pressed. For example, the line drawing button has three further buttons, for horizontal lines, vertical lines, and a "free hand" drawing tool, which generates a polygonal line. It is possible to activate a "magnetic grid" with a user-defined distance between grid points; objects can be positioned and/or scaled by entering numerical values or by dragging with the mouse. There is also a very useful "multiple clone" menu entry (under edit; you need to have an object selected) which can be used to repeat the selected object on the same page (eg. if you need to print your own address label 60 times on the same pre-perforated self adhesive sheet). Using the same menu entry, but with different options selected, it is also possible to repeat the same object rotated, scaled, and/or color-modified. Xact is pretty fast, therefore even an older computer can handle hundreds of graphics objects in a single file, without noticeable performance drop. Besides the vector drawing tools, Xact also imports bitmaps. They can be scaled independently in x- and y-direction, and they can be combined with the vector drawings. Unfortunately, it is still not possible to rotate bitmaps by arbitrary angles (90°, 180°, and 270° works), and transparency in pixel images is not supported. Either you have a bitmap, or you don't have it. I found that it is possible to work around these limitations by doing part of the work in Xact, export the result as a high-resolution bitmap, and complete the project in ImpOS or Embellish.

In most cases, however, Xact has all the capabilities that I need. For example, I draw my floppy and CD-ROM labels and inlays with Xact. I use it to print address labels and visiting cards. When I print photos on glossy ink jet paper, I use it to arrange and scale the images. I also used Xact to generate the invitations to my wedding and to print the menu, the address labels, and the program for the day.

Overall, I'm pretty satisfied with Xact. Probably the best value for money that I ever received in a software purchase.

One more thing: If you buy Xact or Xact Pro, you will receive a CD-ROM with the versions for OS/2, Win16 and Win32. Make sure the people from SciLab know that you want the OS/2 version - they cannot possibly know which version you run, unless you tell them!

References: Xact 7.0 Developer: Scilab Price: Xact 7.0: Single-user EUR 459.14, Academic EUR 203.49, Network (3 copies) EUR 1173.93 Xact Pro: Single-user EUR 714.78, Network (3 copies) EUR 1736.35 Scilab http://www.scilab.de

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