Matlab—A Tool for Doing Numerics
Separate windows are used to display graphics. There is a vast variety of different kinds of plots ranging from simple bar charts to color-shaded 3-D plots with different light sources. Every aspect of a plot can be controlled by setting the appropriate variables. Since 5.3, it is possible to edit a graph directly with a simple point-and-click interface.
A very handy feature is the support of LaTeX-like syntax for text-in-graphics windows.
Exporting images to encapsulated PostScript is possible, although importing the file into, e.g., a (La)TeX document might not lead to the desired result, especially if there is extra text in the figure. Matlab uses fixed-size fonts, so scaling the picture can result in odd-looking tick labels. Therefore, an export mode where text and graphics are written into separate files as in XFig and Xmgr would definitely find friends in the (La)TeX community. For publications, I still export the processed data and import it into Xmgr.
Figure 2 shows the trace of a hall measurement in the two-dimensional electron gas of a GaAlAs heterostructure. The plot was obtained from the commands issued as shown in Figure 3.
Platforms in Matlab do not matter. The only problem that might arise when copying scripts from one platform to the other is CR/LF conversion.
A colleague of ours recently had a problem with a Macintosh at work. It did not have enough memory to display a large matrix, so she issued the command save which stores the current state in the file matlab.mat, copied the resulting file to our Linux server, loaded it under the Linux version of Matlab, and continued her work on Linux.
After the uproar in the Linux community concerning the Mindcraft report, I could not resist running a benchmark with Linux and MS Windows 98. The command bench(N) is a Matlab script that times five different tasks from different fields of numerical math and graphics. Data structures and general math are tested by solving ordinary differential equations (ODE). Floating-point values are the main issue of the Linpack part (LU), sparse matrices mix both integer and floating-point calculation (Sparse), 3-D graphs test z-buffering, and 2-D graphics test line drawing. The parameter N gives the number of times a test is performed. The higher the number, the more reliable the test.
The results of bench(100) are shown in the first two lines of Table 1. The system the test was run on is a 133MHz Pentium with 32MB of RAM. Linux is a bit slower in all cases except when it comes to 2-D graphics, where it is faster. The reason for this might be that the graphics driver for Linux is better than the generic Windows driver. I did not bother to install all possible drivers since VMWare (see “VMWare Virtual Platform” by Brian Walters, July 1999) is now available, and I won't need to reboot the machine any more in order to read an Excel spreadsheet. I installed this PC emulator on our server which has a 400MHz processor and 128MB of RAM. Just for fun, I ran the same benchmark in the emulator and directly on Linux. The results are listed in the remaining lines of the table.
Features in the user interface could be drastically improved—a user-friendly debugger would be great.
I was amazed by the quick response I got from the Matlab newsgroup (comp.soft-sys.matlab). Matlab engineers seem to frequent the forum quite often and provide immediate help and support.
To put it all together, Matlab for Linux is a very useful tool for doing numerical mathematics with a wealth of toolboxes, including signal processing, symbolic computation, financial mathematics and others.
Tobias Vançura (firstname.lastname@example.org) studied physics in Kaiserslautern and Zurich where he is now working on his Ph.D. in semiconductor physics. In his group, he is responsible for a heterogenous computer network consisting primarily of Macintoshes, one NeXT cube, some PCs running most available versions of Windows, and of course, Linux. In his spare time, he loves snowboarding and skiing in winter and tennis in summer.
Practical Task Scheduling Deployment
One of the best things about the UNIX environment (aside from being stable and efficient) is the vast array of software tools available to help you do your job. Traditionally, a UNIX tool does only one thing, but does that one thing very well. For example, grep is very easy to use and can search vast amounts of data quickly. The find tool can find a particular file or files based on all kinds of criteria. It's pretty easy to string these tools together to build even more powerful tools, such as a tool that finds all of the .log files in the /home directory and searches each one for a particular entry. This erector-set mentality allows UNIX system administrators to seem to always have the right tool for the job.
Cron traditionally has been considered another such a tool for job scheduling, but is it enough? This webinar considers that very question. The first part builds on a previous Geek Guide, Beyond Cron, and briefly describes how to know when it might be time to consider upgrading your job scheduling infrastructure. The second part presents an actual planning and implementation framework.
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- Stunnel Security for Oracle
- The Firebird Project's Firebird Relational Database
- Murat Yener and Onur Dundar's Expert Android Studio (Wrox)
- SUSE LLC's SUSE Manager
- Managing Linux Using Puppet
- My +1 Sword of Productivity
- Non-Linux FOSS: Caffeine!
- Doing for User Space What We Did for Kernel Space
- Google's SwiftShader Released
- SuperTuxKart 0.9.2 Released
With all the industry talk about the benefits of Linux on Power and all the performance advantages offered by its open architecture, you may be considering a move in that direction. If you are thinking about analytics, big data and cloud computing, you would be right to evaluate Power. The idea of using commodity x86 hardware and replacing it every three years is an outdated cost model. It doesn’t consider the total cost of ownership, and it doesn’t consider the advantage of real processing power, high-availability and multithreading like a demon.
This ebook takes a look at some of the practical applications of the Linux on Power platform and ways you might bring all the performance power of this open architecture to bear for your organization. There are no smoke and mirrors here—just hard, cold, empirical evidence provided by independent sources. I also consider some innovative ways Linux on Power will be used in the future.Get the Guide