MecLib - Dynamic and Interactive Graphics in STACK questions without JS

Martin Kraska and Dennis Schulz

Technische Hochschule Brandenburg, kraska@th-brandenburg.de

Abstract

STACK is a Moodle question type which comes with built-in support of JSXGraph, a JavaScript library for interactive and dynamic graphics. It is possible to evaluate properties of interactively modified graphics from within STACK and to provide automatic feedback. Authors of STACK questions usually handle HTML, LaTeX and Maxima (the CAS engine used in STACK). MecLib has been developed as a Maxima interface to a pre-defined set of high-level JSXGraph objects. This reduces the complexity of authoring by avoiding the need to even touch Javascript.

MecLib is a JSXGraph block with question-independent content, which is just copied to the question text. All content of the graphics is controlled by a Maxima list of lists in the question variables along with the usual math content like randomization and model answer generation.

The initial driver of the development was the need for asynchroneous interactive learning material for teaching Engineering Mechanics. Starting as an intermediate step towards an interactive editor for free body diagrams, it has evolved into a helpful tool for illustrating STACK questions, be it dynamic and interactive or not, just because of simplicity, portability and consistent design.

Audience: STACK users in STEM subjects