Programming with the XForms Library, Part 2: Writing an Application
If you've managed to pour over xgtsim and get a good feel for what's going on, you may want to try altering the source code to test your understanding. One thing to attempt would be adding an extra button to the Main window that randomizes all the current variables. That is, suppose the user has set payoffs and strategies, but wants to scramble these values. You'll not only have to add the button and set up the callback, but you'll have to update any currently displayed windows to reflect these changes.
The charts in the Run window currently provide only average feedback on the two types of players. Try adding more charts or other elements to display information on the best and worst players in each category.
If you're feeling really ambitious, then try altering xgtsim to allow for more actions and more complicated strategies. This can get very complicated, since elements like the payoff matrix will have to grow and shrink depending on how many actions are currently possible. This can be accomplished by dynamically creating new objects and forms, something we haven't covered so far.
In playing with xgtsim, you may find a set of strategies and payoffs that generate interesting results. Currently there's no way to save this state of the game, because we have no file-based input and output. We'll be adding that next month, by using XForms pre-built file requester routine. It's just part of a whole set of “goodies” that XForms includes, and we'll be looking at most of them.
We'll also spiff up our application with some pixmaps, learn how to set gravity parameters to control window resizing, and look at a few other interesting features of XForms.
Thor Sigvaldason is the author of the statistics program xldlas which uses the XForms library (see LJ #34, February, 1997). He is trying to finish a PhD in economics, and can be reached at email@example.com.
Practical Task Scheduling Deployment
July 20, 2016 12:00 pm CDT
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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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