# ScienceKDE

KDE for scientific work

## Tag Archives: plasma

## Advanced calculator runner

December 7, 2010

Posted by on Hello Planet!

since this is my first post on the Planet, I’ll shortly introduce myself and my activities in KDE. My name is Matteo and I am the maintainer of the Qalculate plasmoid and runner since SC 4.5. I am also the founder and maintainer of Cirkuit, a KDE app to produce publication-ready graphics using different backends (TikZ, Circuit Macros, Gnuplot).

In this post, I would like to describe some features that have been introduced in SC 4.5 (and polished for SC 4.6) in the Calculator runner. The reason for this post is that apparently many people are not familiar with many of the features offered by the Calculator runner since 4.5.

First of all, how do you use the runner? Simply press ALT+F2 and type a mathematical expression with a ‘=’ sign at the beginning or at the end of the statement, as shown in the figure below.

Since KDE SC 4.5, the calculator runner has an optional (compile-time) dependency on libqalculate. So, if you compiled kdebase with libqalculate support enabled, the runner has some “advanced” features, like unit conversion, exchange rates, equation solving, and many more.

This means that you can perform calculations involving Newton’s laws of motion or Ohm’s law just by pressing ALT+F2 and typing the expression (see pictures below).

You can’t remember the derivative or integral of a certain function? This can also be accomplished by the runner:

You can also solve equations:

You can find out additional features at the Qalculate website. I will write an additional post about the Qalculate plasmoid, illustrating more features of the Qalculate engine. Feel free to suggest improvements in the comments.