KDE

Study the Elements with KDE's Kalzium

Joey Bernard — Wed, 19 Jun 2019 12:00:00 +0000

I've written about a number of chemistry packages in the past and all of the computational chemistry that you can do in a Linux environment. But, what is fundamental to chemistry? Why, the elements, of course. So in this article, I focus on how you can learn more about the elements that make up everything around you with Kalzium. KDE's Kalzium is kind of like a periodic table on steroids. Not only does it have information on each of the elements, it also has extra functionality to do other types of calculations.

Kalzium should be available within the package repositories for most distributions. In Debian-based distributions, you can install it with the command:


sudo apt-get install kalzium

When you start it, you get a simplified view of the classical periodic table.

Figure 1. The default view is of the classical ordering of the elements.

You can change this overall view either by clicking the drop-down menu in the top-left side of the window or via the View→Tables menu item. You can select from five different display formats. Clicking one of the elements pops open a new window with detailed information.

Figure 2. Kalzium provides a large number of details for each element.

The default detail pane is an overview of the various physical characteristics of the given element. This includes items like the melting point, electron affinity or atomic mass. Five other information panes also are available. The atom model provides a graphical representation of the electron orbitals around the nucleus of the given atom. The isotopes pane shows a table of values for each of the known isotopes for the selected element, ordered by neutron number. This includes things like the atomic mass or the half-life for radioactive isotopes. The miscellaneous detail pane includes some of the extra facts and trivia that might be of interest. The spectrum detail pane shows the emission and absorption spectra, both as a graphical display and a table of values. The last detail pane provides a list of external links where you can learn more about the selected element. This includes links to Wikipedia, the Jefferson Lab and the Webelements sites.

Figure 3. For those elements that are stable enough, you even can see the emission and absorption spectra.

Go to Full Article

Plotting on Linux with KmPlot

Joey Bernard — Fri, 26 Apr 2019 12:00:00 +0000

by Joey Bernard

This issue of Linux Journal marks the magazine's 25th anniversary. So, I thought I'd look back to see when I wrote my first article, and I was horrified to see that it was in 2000. I'm too young to have been writing articles for more than 18 years! Here's to another 25 years for Linux Journal and all of the authors who have made it what it is.

For this article, let's take a look at the KmPlot plotting program. KmPlot is part of the EDU suite of programs from the KDE project, and it was designed to plot functions and interact with them to learn about their behavior. Since it is a part of the KDE project, it should exist in most package management systems. For example, in Debian-based systems, you can install it with the command:


sudo apt-get install kmplot

When you first start KmPlot, you'll see a blank workspace where you can start to play with mathematical functions. On the right-hand side, there's a main plot window where all of the graphical display will happen. On the left-hand side, there's a function list window where you can find all of the functions you've defined and are planning on working with.

Figure 1. Upon start up, you can begin entering functions and learning about their behavior.

The first thing to do is create some functions to use from within KmPlot. Click the Create button at the bottom of the function window to bring up a drop-down menu. Here you can select from a number of plot types, such as Cartesian, polar or differential. As an example, clicking the Cartesian option opens a new window where you can create your function.

Figure 2. You can use the built-in palettes to select functions and constants to build up the functions that you are interested in.

You can use pre-defined constants and simpler functions to build up the specific function you want to study. Once you're finished, KmPlot will update the main window, and you'll see your plot generated.

Several defaults exist that you can assign in terms of its appearance. Click the Advanced button at the bottom of the left-hand pane to open a new dialog window where you can change some of the defaults.

Figure 3. Click the Advanced button to set several options in the plot window.

Go to Full Article

FOSS Project Spotlight: Nitrux, a Linux Distribution with a Focus on AppImages and Atomic Upgrades

Nitrux Latinoamericana S.C. — Fri, 21 Sep 2018 13:41:37 +0000

by Nitrux Latinoa…

Nitrux is a Linux distribution with a focus on portable, application formats like AppImages. Nitrux uses KDE Plasma 5 and KDE Applications, and it also uses our in-house software suite Nomad Desktop.

What Can You Use Nitrux For?

Well, just about anything! You can surf the internet, word-process, send email, create spreadsheets, listen to music, watch movies, chat, play games, code, do photo editing, create content—whatever you want!

Nitrux's main feature is the Nomad Desktop, which aims to extend Plasma to suit new users without compromising its power and flexibility for experts. Nomad's features:

The System Tray replaces the traditional Plasma version.
An expanded notification center allows users to manage notifications in a friendlier manner.
Easier access to managing networks: quick access to different network settings without having to search for them.
Improved media controls: a less confusing way to adjust the application's volume and integrated media controls.
Calendar and weather: displays the traditional Plasma calendar but also adds the ability to see appointments and the ability to configure location settings to display the weather.
Custom Plasma 5 artwork: including Look and Feel, Plasma theme, Kvantum theme, icon theme, cursor themes, SDDM themes, Konsole theme and Aurorae window decoration.

Nitrux is a complete operating system that ships the essential apps and services for daily use: office applications, PDF reader, image editor, music and video players and so on. We also include non-KDE or Qt applications like Chromium and LibreOffice that together create a friendly user experience.

Available Out of the Box

Nitrux includes a selection of applications carefully chosen to perform the best when using your computer:

Dolphin: file manager.
Kate: advanced text editor.
Ark: archiving tool.
Konsole: terminal emulator.
Chromium: web browser.
Babe: music player.
VLC: multimedia player.
LibreOffice: open-source office suite.
Showimage: image viewer.

Explore a Universe of Apps in Nitrux

The NX Software Center is a free application that provides Linux users with a modern and easy way to manage the software installed on their open-source operating systems. Its features allow you to search, install and manage AppImages. AppImages are faster to install, easier to create and safer to run. AppImages aim to work on any distribution or device, from IoT devices to servers, desktops and mobile devices.

Go to Full Article

A Look at KDE's KAlgebra

Joey Bernard — Thu, 13 Sep 2018 12:00:00 +0000

by Joey Bernard

Many of the programs I've covered in the past have have been desktop-environment-agnostic—all they required was some sort of graphical display running. This article looks at one of the programs available in the KDE desktop environment, KAlgebra.

You can use your distribution's package management system to install it, or you can use Discover, KDE's package manager. After it's installed, you can start it from the command line or the launch menu.

When you first start KAlgebra, you get a blank slate to start doing calculations.

Figure 1. When you start KAlgebra, you get a blank canvas for doing calculations.

The screen layout is a large main pane where all of the calculations and their results are displayed. At the top of this pane are four tabs: Calculator, 2D Graph, 3D Graph and Dictionary. There's also a smaller pane on the right-hand side used for different purposes for each tab.

In the calculator tab, the side pane gives a list of variables, including predefined variables for things like pi or euler, available when you start your new session. You can add new variables with the following syntax:


a := 3

This creates a new variable named a with an initial value of 3. This new variable also will be visible in the list on the right-hand side. Using these variables is as easy as executing them. For example, you can double it with the following:


a * 2

There is a special variable called ans that you can use to get the result from your most recent calculation. All of the standard mathematical operators are available for doing calculations.

Figure 2. KAlgebra lets you create your own variables and functions for even more complex calculations.

There's also a complete set of functions for doing more complex calculations, such as trigonometric functions, mathematical functions like absolute value or floor, and even calculus functions like finding the derivative. For instance, the following lets you find the sine of 45 degrees:


sin(45)

You also can define your own functions using the lambda operator ->. If you want to create a function that calculates cubes, you could do this:


x -> x^3

This is pretty hard to use, so you may want to assign it to a variable name:


cube := x -> x^3

You then can use it just like any other function, and it also shows up in the list of variables on the right-hand side pane.

Go to Full Article

Astronomy on KDE

Joey Bernard — Thu, 09 Aug 2018 12:15:15 +0000

by Joey Bernard

I recently switched to KDE and Plasma as my main desktop environment, so I thought I'd start digging into some of the scientific software available on KDE. First up is KStars, the desktop astronomy program.

KStars probably won't be installed with the standard KDE desktop, so you may need to install it. If you're using a Debian-based distribution, you can install KStars with the following command:


sudo apt-get install kstars

When you first start it, KStars asks for your current location, and then it gives you the option of installing several extra information files to add to the list of objects that KStars knows about and can display. Once those steps are finished, KStars begins with the current sky at the location you entered earlier.

Figure 1. On startup, KStars shows you the current layout of the sky in your location.

So, what can you do with KStars? If you've used programs like Stellarium before, you'll find that you can do the same types of tasks with KStars. You can use your mouse to click and drag the display to change the direction you're facing. The cardinal directions are labeled along the outside of the circle of the sky, and you can zoom in and out to change the field of view. If you see an object you want to examine further, you can double-click it to center it on the display and tag it as the current object of interest.

Depending on what catalogs of data you installed, some of the objects may have more or less information available. For example, selecting the planet Uranus and zooming all the way in shows a reasonably detailed image of the planet, including the ring orientation.

Figure 2. You can easily select and zoom in to objects of interest in KStars.

Quite a few options are available for controlling what's shown in the main window. The toolbar across the top of the window allows you to toggle the following items: stars, deep sky objects, solar system objects, supernovae, satellites, constellation lines, constellation names, constellation art, constellation boundaries, Milky Way, equatorial coordinate grid, horizontal coordinate grid and opaque ground. This allows you to customize the display so that it shows only what you're interested in at the time. The last display option is to toggle the "What's Interesting" pane.

Go to Full Article

Astronomy for KDE

Joey Bernard — Thu, 23 Jun 2016 21:00:00 +0000

by Joey Bernard

Although I have covered a large number of science applications in the past, I haven't really looked at too many options available within the KDE desktop environment. This has been due to my own biases in using a GTK-based desktop environment, but now I'd like to look at some of the packages available for people who really like to use KDE on their own machines. So, let's start with the KStars astronomy program.

If you have the full KDE environment installed, you already should have it available. If you don't, you should be able to install it. For example, you can install KStars on Debian-based distributions with this command:


sudo apt-get install kstars

If this is the first KDE-based application that you are installing, it also will need to pull in a rather large set of dependencies—that's just the price of using a new GUI toolkit. Of course, any other packages will be incrementally smaller since all of the shared dependencies already will be there.

To launch KStars, you either can click on a menu item in your desktop environment or enter the kstars command in a terminal window. The first time you start KStars, you need to go through the setup wizard to configure elements like your location. Once KStars finishes starting up, you should see a display of the sky from the location you set during the setup.

Figure 1. When you first start KStars, you need to go through the setup wizard.

Figure 2. You get a display of the sky from your location when KStars starts.

You can pan the display around simply by clicking and dragging the star field to see locations of interest. The items that are labeled depend on your zoom level. Two buttons at the top of the display allow you to zoom in and out. Beside these is a third button, labeled Find Object, that you can click on to get a search window. This window can use filters to search for particular types of objects, like comets or asteroids, or you can search through all of the objects that KStars knows about.

Once you find an object of interest, you can click on it and have the display move around until the object is in the center of the display. If it is below the horizon, a warning box will pop up asking if you still want to re-center the display. Once you have selected your object, you can right-click on it to get a drop-down menu of things you can do with it.

Go to Full Article

KDE Reveals Plasma Mobile

James Darvell — Tue, 28 Jul 2015 14:15:56 +0000

by James Darvell

There are a lot of interesting developments occurring in the field of Linux smartphones right now. With so many different options popping up, fragmentation is a risk, as apps built on one platform fail to migrate to another. KDE's new offering may help to make those apps available to a broader audience.

KDE Plasma Mobile is a new software stack for Linux phones, and it's designed to provide a user-friendly and open interface for users. The project still is in its early stages, but there is a working prototype, which you can see demoed in this video: https://www.youtube.com/watch?feature=player_embedded&v=auuQA0Q8qpM.

Unlike Ubuntu Phone or Firefox OS, KDE Plasma Mobile is not a complete operating system. It's a combination of packages that provides a user interface for a phone. It also exposes the features of the phone to user apps through software, such as Ofono and RIL. Currently, Plasma Mobile supports Qt apps, including KDE Desktop apps and Plasmoids. The platform also aims to support Ubuntu Phone apps (which are packaged by Snappy) and Android apps.

The reason behind the project is to put users in control. Android itself may be an open platform, but most Android devices are tied into a specific App store by the manufacturer. And, the majority of Android apps are not free (in the "free speech" sense). The mobile app market currently favors proprietary apps with embedded advertising (which uses tracking in order to target ads better) and in-app purchases. This is in addition to apps that demand access to users' social media accounts and other private data. Users actively are blocked from installing apps from other sources, and they often have to go through a complex procedure of "rooting" their devices just to be able to install software that isn't in the stores.

For users who are concerned about privacy and freedom, smartphones can be a bit of a nightmare. KDE's platform puts the focus on open-source apps and creates a level playing field on which developers can construct programs that are native and portable (thanks to Qt). At the same time, users will be free to add apps, such as Google Play, and install Android apps as they wish.

Plasma Mobile is an interesting project for developers too. By leveraging familiar technologies, such as Qt and dbus, it will be easier to port existing apps and create new ones, without having to learn idiosyncratic APIs (such as the Android API and Google Play API).

Go to Full Article

Linus Ditches KDE and Gnome (so what?)

Michael Reed — Fri, 26 Aug 2011 15:16:17 +0000

by Michael Reed

Having made an earlier defection from KDE to Gnome, Linus Torvalds has now rejected both in favor of Xfce. It’s only natural that the actions of the creator of the Linux kernel would attract extra scrutiny, and I think that his decision is reflective of a wider disenchantment amongst long-term Linux users.

So is this post a sky-is-falling complain-fest? Not at all. It might be time for some of us to say, “I don’t like the way that the big two DEs are shaping up, so, I’m going to use something else.”

There was a time when KDE was the desktop for geeks who liked an intricate, customizable interface and Gnome had found its niche as a business desktop. No prizes for guessing which one Linus chose. However, upon the introduction of KDE4, he jumped ship in favor of Gnome 2. He stated that he was disappointed with the performance and reliability of KDE4, in addition to being unconvinced about the new direction that the developers were taking.

He made the announcement of his latest defection via Google+. His first remark was fairly benign:

“While you are at it, could you also fork gnome, and support a gnome-2 environment?”

but then he followed up with some more specific and scathing criticisms:

“I want my sane interfaces back. I have yet to meet anybody who likes the unholy mess that is gnome-3.”

“In gnome3, the developers have apparently decided that it's "too complicated" to actually do real work on your desktop, and have decided to make it really annoying to do.”

“I'm using Xfce. I think it's a step down from gnome2, but it's a huge step up from gnome3. Really.”

Ouch. But also... not ouch. I think that there’s a positive side to all of this. Linus wants to get back to what he considers to be his favorite era of the Linux desktop. What we’re talking about here is a desktop that uses an interface mechanic that is reminiscent of both MacOS and Microsoft Windows and that favors a modular approach to application selection. KDE4 and Gnome 3 are breaking with traditional desktop mechanics while introducing some new elements. KDE4 fails on the second criteria of the the “classic” Linux DE as it will increasingly make use of highly integrated applications.

Go to Full Article

Kde 4.7 Released And In The Wild

Michael Reed — Mon, 01 Aug 2011 13:00:00 +0000

by Michael Reed

July saw the release of KDE SC 4.7. Like all recent KDE releases, this is a combination of updates to the bundled applications, underlying desktop and associated technologies. Canonical have already pushed 4.7 through to Kubuntu desktops.

If you are a 4.6 user who has just upgraded, don’t expect to be aware of major changes the first time you reboot. Some of the core applications have been updated, but most of the work has gone into improving the underlying frameworks. The applications themselves have been shifted to a greater reliance on Akonadi, the PIM storage framework and NEPOMUK, the semantic information database.

Kontact is the KDE PIM suite that includes email, contacts and appointments. Again, don’t expect to see many apparent differences when using the applications as most of the changes take the form of a switch to Anakondi for data storage. The mail component, Kmail is an example of this as it has been rechristened Kmail 2, although it looks almost identical to the previous version.

Of course, the the usual caveats about relying on a database rather than standard file formats have to be considered. On the one hand, it’s not quite clear what happens if you have to recover a broken system as you can’t simply peer inside a set of standard files. On the other, a unified approach looks set to pay off in the future, and it was always part of the over-arching plan for KDE4.

Increasingly, if you update contact or scheduling information in one application, that information will be updated in every KDE application, and this will include all of your synchronized devices and services. However, if you’re the type of user who prefers to use a suite of independent applications that utilize industry standard methods of storing their data, the KDE of the future isn’t going to be for you.

Photo manager, digKam is once again a core application, and it’s an example of an application that does have improvements that are visible on the surface. As for the application itself, it will probably continue to be divisive. On the one hand, it harks back to the KDE3 era in that it is a complicated application with loads of features. On the other hand, it’s at odds with the KDE4 aim to simplify user interfaces wherever possible. I’d challenge anyone who has not used it before to be able to figure it out at first glance, in contrast to the intuitive layout of F-Spot or Picasa. It’s a techy application application rather than a pure photo browser, and some people will want to see it stay that way.

digiKam - it's complicated.

Go to Full Article

KDE4: It hurt, but did it work?

Michael Reed — Thu, 01 Apr 2010 15:14:40 +0000

by Michael Reed

Last month's release of the KDE 4.4 desktop environment restored the faith of many after what has been something of a roller coaster two years. Even the most loyal KDEians found that loyalty stretched by the debut of version 4.0 in 2008. Reassessing, and with hindsight, I think it's fair to characterize the whole saga as both a cautionary tale and an admirable example. Admirable, because the KDE team has displayed a quality that is so often lacking in open source software development: leadership.

By 2008, thanks to its stability, performance and feature-set, KDE3 had become one of the best desktops on the computer scene. However, it was becoming clear that a successor, KDE4, would represent a significant break with the past - the best was about to get even better. More than a mere upgrade, it was to be a complete rewrite and absolutely packed with mouth-watering technology. To the credit of the development team, they released largely on time, but it was a release that pushed the community first to bafflement and then resentment. It was unusable - and when I say unusable, I mean it literally couldn't be used for any serious work - due to stability and performance problems. To most people, a 4.0 release means a new version of a finished product, yet the general consensus was that KDE4 ran like an alpha. To top it off, it lagged behind KDE3 in terms of features.

The other jarring aspect of KDE4 was that the changes that had been made were so bold. For example, music player Amarok had been an application that had evoked the sacred phrase, "killer app", magic words that desktop Linux desperately needs to have associated with it. It was, however, like so many of the old favorites, nominated for a rewrite and redesign. It's much improved since the initial, disappointing release, but it still doesn't quite have feature parity with the final KDE3 version. Konqueror, the file manager/web browser combination was another beloved, if slightly eccentric, KDE fixture that found itself depreciated in favor of something new.

Just what were team KDE thinking in terms of pushing me out of my comfort zone? The answer: they were doing what had to be done. KDE had reached the end of the line and needed to be restarted to keep up, and begin to lead, in the world of desktop environments. Some of the decisions were criticized, but there's a saying that good leadership is always in dispute. The problems that did crop up were due to poor communication and a determination to release on schedule, no matter what.

Two years on, things are back on track. It's perhaps time to begin a campaign of telling people who left KDE, "it's safe to come back!". As it stands, not only is KDE 4.4 a superb desktop, thanks to the new frameworks that are now in place the potential for new developments is almost overwhelming. Personally, I wouldn't hesitate to recommend KDE4. However, it's been a rocky couple of years getting here.

Go to Full Article