Texture-based Visualization of Metrics on Software Architectures

We present a method that combines textures, blending, and scattered-data interpolation to visualize several metrics defined on overlapping areas-of-interest on UML class diagrams. We aim to simplify the task of visually correlating the distribution and outlier values of a multivariate metric dataset with a system’s structure. We illustrate our method on a class diagram of a real-world system.

LePUS3: An Object-Oriented Design Description Language

LePUS3 [1] (lepus.org.uk) is a logic, visual, object-oriented Design Description Language: a formal specification language designed to capture and convey the building-blocks of object-oriented design. LePUS3 minimal vocabulary constitutes of abstraction mechanisms that can specify effectively and precisely design patterns and the design of JavaTM (C++, Smalltalk, etc.) programs at any level of abstraction

Automated Verification of Design Patterns with LePUS3

Specification and [visual] modelling languages are expected to combine strong abstraction mechanisms with rigour, scalability, and parsimony. LePUS3 is a visual, object-oriented design description language axiomatized in a decidable subset of the first-order predicate logic. We demonstrate how LePUS3 is used to formally specify a structural design pattern and prove (‗verify‘) whether any JavaTM 1.4 program satisfies that specification. We also show how LePUS3 specifications (charts) are composed and how they are verified fully automatically in the Two-Tier Programming Toolkit

Graph Creation, Visualisation and Transformation

We describe a tool to create, edit, visualise and compute with interaction nets - a form of graph rewriting systems. The editor, called GraphPaper, allows users to create and edit graphs and their transformation rules using an intuitive user interface. The editor uses the functionalities of the TULIP system, which gives us access to a wealth of visualisation algorithms. Interaction nets are not only a formalism for the specification of graphs, but also a rewrite-based computation model. We discuss graph rewriting strategies and a language to express them in order to perform strategic interaction net rewriting

The State-of-the-Art of Set Visualization

Sets comprise a generic data model that has been used in a variety of data analysis problems. Such problems involve analysing and visualizing set relations between multiple sets defined over the same collection of elements. However, visualizing sets is a non-trivial problem due to the large number of possible relations between them. We provide a systematic overview of state-of-the-art techniques for visualizing different kinds of set relations. We classify these techniques into six main categories according to the visual representations they use and the tasks they support. We compare the categories to provide guidance for choosing an appropriate technique for a given problem. Finally, we identify challenges in this area that need further research and propose possible directions to address these challenges. Further resources on set visualization are available at http://www.setviz.net

A Meta-Model-Based Approach for Specification of Graphical Representations

Meta-models are widely used for the specification of the international structure of graph modelling languages, and well-established standards (e.g. MOF) exist for this. For the graphical representation there is not the same agreement and no related standards. This paper presents a new meta-langauge for an independent specification of graphical representations. A diagram from the domain-specific language Service is used as a running example to show how this meta-model-based approach is appropriate for specifying the graphical representation in a precise way, but still on a high level of abstraction

Constraint-based run-time state migration for live modeling

Live modeling enables modelers to incrementally update models as they are running and get immediate feedback about the impact of their changes. Changes introduced in a model may trigger inconsistencies between the model and its run-time state (e.g., deleting the current state in a statemachine); effectively requiring to migrate the run-time state to comply with the updated model. In this paper, we introduce an approach that enables to automatically migrate such runtime state based on declarative constraints defined by the language designer. We illustrate the approach using Nextep, a meta-modeling language for defining invariants and migration constraints on run-time state models. When a model changes, Nextep employs model finding techniques, backed by a solver, to automatically infer a new run-time model that satisfies the declared constraints. We apply Nextep to define migration strategies for two DSLs, and report on its expressiveness and performance