Wednesday, January 31, 2007

The Road to KDE 4: Kalzium and KmPlot

Since not all of the development for KDE 4 is in base technologies, this week features two of applications from the KDE-Edu team: Kalzium, a feature-filled chemistry reference tool, and KmPlot, a powerful equation graphing and visualization program. Read on for the details.
These educational tools have received a lot of work for KDE 4. In particular, Kalzium and KmPlot developments are happening at an amazing rate.
Kalzium (the German word for Calcium) has been a part of KDE since version 3.1 and is now one of the most useful applications developed by the KDE-Edu team. Initially it was just a program that displayed the periodic table, alongside some useful numbers like atomic weights, boiling points, etc. It was later extended to include a lot of background information on the elements, and more detailed chemistry information (such as emission spectra) which made it a very useful chemistry reference.

In KDE 3.5.5 (which I used for these screenshots, even though 3.5.6 was released last week), Kalzium looks something like this when first loaded:

Kalzium in KDE 3.5.5
Click for fullsize.

You can see that the interface is pretty simple, and presents a lot of information. If you click on an element it brings up even more information on its properties.

The main user interface in KDE 4 does not look that different, except for the fact that Qt 4 introduces some appearance changes, and there are some more icons (some that haven't been drawn yet) in the toolbar. Here's a peek at Kalzium in the KDE 4 development series:

Kalzium in KDE 4x devel
Click for fullsize.

So Kalzium is visually quite similar between versions at this point. However, the important thing to note in the KDE 4 screenshot is the tools menu. In KDE 3.5.5, this menu contains only Plot Data and Glossary.

Plot Data shows the elements plotted in a variety of useful ways, such as mass, radius, electronegativity, etc. while the Glossary shows definitions for many of the more common chemical terms. It is apparently missing the above mentioned electronegativity, so evidently there is still room for improvement here. Making improvements to the Glossary would be a great opportunity for a chemistry-inclined person to contribute to Kalzium in KDE 4 without having to be a programmer.

Anyway, back to the new tools. I'll focus on a few of the newly developed tools that will make Kalzium even more useful in KDE 4:

The isotope table will display a list of isotopes and their decay methods - as a geologist for example, it is important for me to know that Potassium-40 usually decays by electron capture.

The new equation solver is also quite useful, as seen in the following screenshot provided by Kalzium lead developer Carsten Niehaus:

Kalzium Equation Solver in KDE 4x devel

You basically just punch in a chemical equation leaving letters in place of the numbers you are looking for, and it spits out a response. In high school chemistry, students are expected to be able to solve these sorts of equations manually, but like most equations, once you solve enough of them, it simply becomes tedious. This equation solver can save a lot of time for complex equations.

And finally, the most visible change to Kalzium is the inclusion of the Kalzium 3D work, which turns the program into a 3D molecule viewer. Initially, it was developed by the Kalzium developers for use in this application only, but some collaboration has since happened and it will now be using libavogadro a library jointly developed by the Kalzium and Avogadro developers.

According to the Kalzium developers work is progressing on porting the 3D modeller to use libavagadro, an effort led by Donald Curtis, providing a more general/powerful framework for rendering/manipulating molecules with Qt and OpenGL library. It is shared between Kalzium and Avogadro (and more). Avogadro is a much more advanced molecular modelling programs, useful for creating the actual molecule files, and doing quantum chemistry. Kalzium 3D will simply act as a viewer for files constructed using these programs.

Kalzium developer BenoƮt Jacob submits the following screenshot showing the 3D molecule viewer in action using the new Kalzium 3D functionality. This functionality is already SVN as this article goes to press, however work continues with libavogadro integration.

Kalzium 3d in KDE 4x devel
Click for fullsize.

Kalzium will likely ship with a library of common molecules ready to view provided by the BlueObelisk project. Thanks to the OpenBabel library, it should also be able to open molecule files in a huge variety of formats (I counted 62 file formats that it already supports).
On to our next KDE-Edu feature: KmPlot. For a while already, this application has had the ability to plot regular functions, parametric functions, and polar functions, as well as show derivatives (or regular functions) and a few other goodies. It has been useful as an equation visualization tool, but the interface has been awkward, with many little cluttered dialogs to fight with.

Below is KmPlot in KDE 3.5.5 with it's default settings, and three functions plotted, one of each type:

KmPlot in KDE 3.5.5

The dialogs used to plot these equations look something like this, except there is one unique dialog for each type of plot:

KmPlot dialog in KDE 3.5.5

Here's a quick look of the new KmPlot interface with the same three functions plotted. No more dialogs to mess with, and the plots can be in shapes other than square! Plus Qt 4 gives everything a nice anti-aliased touch.

KmPlot in KDE 4x devel
Click for fullsize.

KmPlot has received a huge amount of work, and should be one of the KDE 4's killer apps for students, engineers, and more. It plots differential equations now, has a new equation editor, and (as seen in the above screenshot) gives tips as to how to correct your equations.

The new equation editor is shown below with a differential equation being edited:

KmPlot equation editor in KDE 4x devel

As you can see, it's much easier to enter an equation when you can design the functions in a nice syntax checking editor like this one. There is a lot more work going into KmPlot than I can describe in just this article, so if you are interested in more information, check out its development status page.
KDE-Edu is a growing project, with many great applications being developed for a wide variety of age groups. They will have support for Windows and Mac as well, thanks to the improved QT 4 and KDE 4 libraries, and should become more popular programs as a result. Since there is so much great work happening here, expect some other KDE-Edu applications to show up in future articles.
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