C.a.R.

Compass and straightedge or short Z.u.L. ( in other languages ​​Compass and Ruler or short CaR ) is an application software in the field of dynamic geometry systems. The software was developed by René Groth husband, a math professor at the Catholic University of Eichstätt. First versions for the Atari ST were already available in 1988 and were among the pioneers in the field of dynamic geometry. The current Java version has been developed since 1995. Since 2005, there is a spin-off called CARmetal which enjoys great popularity especially in France.

Functions

In addition to the usual functions of a software for dynamic geometry CaR sets special emphasis on the automatic creation of web pages with embedded designs. Z.u.L. provides to a Java applet prepared interactively displays the created structures (file name extension ZIR ) in the web browser. On the website of the program you will find examples of learning environments that include a large part of the school geometry, areas of physics and some selected topics of university geometry.

Additionally, it has Z.u.L. a mode for automatic local lines, which runs completely through the local lines, even if it means cutting points must be changed; numerical skills to implicit plots, modes for three-dimensional plots, non-Euclidean geometries and other details that are not found in other programs of Dynamic Geometry.

For non- interactive presentation purposes, structures as a raster (PNG ) or as a lossless scalable vector graphics (EPS, SVG or PDF) can be exported. The software and partly also to the documentation have been translated into numerous languages, including into Slovenian.

CARmetal

The distributors in France math teacher Eric Hakenholz developed since 2005 on the Java source code of CaR based spin-off called CARmetal (named after the used metal - look-and -feel ). Unlike the original, where many adjustments must be made in dialog boxes, allows the graphical user interface of CARmetal direct access to many elements of the current design. A familiar as graphics software tool palette provides quick access to design tools and object properties such as line width and color. Other features include the ability to create three-dimensional ( barycentric ) looking constructions as well as to give magnetic properties points. A JavaScript interface allows to embed program logic in the constructions or to influence the created Java applets from outside. As C.a.R. has been translated into numerous languages ​​also CARmetal.

In addition Hakenholz published a web magazine called CARzine in which several authors article on CaR and CARmetal publish in French or English.

Comparison with other dynamic geometry software

Z.u.L. provides a similar functionality as the commercially sold programs Euclid and Cabri Geometry, but unlike these not restricted as a Java -based system to Windows and offers the graphics and applet export wider and especially vector-based solutions.

In the open source area offers Z.u.L. more functionality than the no longer developed since 2008 Geonext and is also with the Java-based GeoGebra in the Geometry area on the same, the addition of dynamic geometry, however, a more extensive function plotter as CaR as well as a spreadsheet offers. GeoGebra is pursuing an integrated approach and combines geometric objects always with their algebraic representation. Z.u.L. however, this integration does not, but allowed along with its offshoot CARmetal a powerful open-source offering that meets all aspects of a dynamic geometry program and a purely design, coordinate -free approach to geometry.