GeCla, short for Generator and Classifier, is a program for exploring the symmetries of of patterns/friezes or rosettes in the plane. GeCla allows you to generate a pattern, a frieze or a rosette with a previously chosen kind of symmetry starting from an asymmetric motif. It also allows the classification (with or without help from the program) of the patterns, friezes, rosettes obtained in this manner.
The generator writes encoded information about the existing symmetries in the jpg image file generated. Then the classifier reads and interprets this coded information, which allows it (according to the level of aid chosen) to give information about how the classification process is going, preventing wrong choices, or only indicating at the end whether the classification is correct and, if not, indicating the first mistake.
GeCla also includes a competition option that can be used via the Internet. In it, each player generates a pre-agreed number of images and then both exchange images and each classifies the other’s images. All steps are managed by the program, which in the end provides a report on eventual mistakes.
GeGla was developed by the portuguese association Atractor, after its previous DVD-program “Symmetry - the dynamical way”. GeCla was designed attempting to be attractive and accessible to students of various levels of education. GeCla is available in Portuguese, English, Italian, German and Spanish.