Pattern-Based Layout Specifications for Visual Language Editors

When creating an editor for a visual language, a challenging task is the layout specification. Many visual languages, e.g., Ecore diagrams or Petri nets, show similar layout characteristics, and hence reuse of layout behavior should be enabled. For that purpose, we introduce the concept of layout patterns, which encapsulates certain layout behavior. With the approach, it is possible to combine different layout algorithms, e.g., standard graph drawing algorithms and constraint-based algorithms. In addition, rule-based layout algorithms may be used that are specifically tailored to the interactive nature of visual language editors

A Pattern-Based Layout Algorithm for Diagram Editors

The diagram editor generator framework DIAMETA utilizes meta-model-based language specifications and supports free-hand as well as structured editing. We presented a generic layout algorithm that meets the demands of this kind of editors. The algorithm combines two concepts, constraint satisfaction and attribute evaluation, to a powerful methodology for specifying the layout for a particular visual language. As the layout specification for this algorithm is rather complex, we encapsulated basic functionality into reusable patterns. This paper describes this pattern concept of the generic layout algorithm, and shows how they simplify the layout specification of a specific language

Automating the layout of network diagrams with specified visual organization.

Network diagrams are a familiar graphic form that can express many different kinds of information. The problem of automating network-diagram layout has therefore received much attention. Previous research on network-diagram layout has focused on the problem of aesthetically optimal layout, using such criteria as the number of link crossings, the sum of all link lengths, and total diagram area. In this paper the authors propose a restatement of the network-diagram layout problem in which layout-aesthetic concerns are subordinated to perceptual-organization concerns. The authors present a notation for describing the visual organization of a network diagram. This notation is used in reformulating the layout task as a constrained-optimization problem in which constraints are derived from a visual-organization specification and optimality criteria are derived from layout-aesthetic considerations. Two new heuristic algorithms are presented for this version of the layout problem: one algorithm uses a rule-based strategy for computing a layout; the other is a massively parallel genetic algorithm. The authors demonstrate the capabilities of the two algorithms by testing them on a variety of network-diagram layout problems.Engineering and Applied Science

Combination of Different Layout Approaches

In an interactive environment such as a visual language editor, it is not sufficient to apply the same layout algorithm in every situation. Instead, the user often wants to select the layout behavior at runtime. With the approach presented, the user can control the layout behavior by choosing different layout patterns for different parts of a diagram, e.g., a graph drawing algorithm may be applied to some selected components while others are aligned vertically or horizontally. To enable the specification of layout behavior, we introduced the concept of layout patterns in previous work. Each layout pattern encapsulates certain layout behavior, and hence enables modularization and reuse. To specify user-controlled layout behavior, a flexible combination of arbitrary layout patterns needs to be enabled. Therefore, we introduce an approach that is capable of combining diverse layout approaches, such as standard graph drawing algorithms, constraint-based algorithms, or rule-based layout algorithms. More specifically, an algorithm is presented that automatically computes the complete layout in a straightforward way

SBML Level 3 package: Render, Version 1, Release 1

Many software tools provide facilities for depicting reaction network diagrams in a visual form. Two aspects of such a visual diagram can be distinguished: the layout (i.e.: the positioning and connections) of the elements in the diagram, and the graphical form of the elements (for example, the glyphs used for symbols, the properties of the lines connecting them, and so on). This document describes the SBML Level 3 Render package that complements the SBML Level 3 Layout package and provides a means of capturing the precise rendering of the elements in a diagram. The SBML Level 3 Render package provides a flexible approach to rendering that is independent of both the underlying SBML model and the Layout information. There can be one block of render information that applies to all layouts or an additional block for each layout. Many of the elements used in the current render specification are based on corresponding elements from the SVG specification. This allows us to easily convert a combination of layout information and render information into a SVG drawing

Modelling data intensive web sites with OntoWeaver

This paper illustrates the OntoWeaver modelling approach, which relies on a set of comprehensive site ontologies to model all aspects of data intensive web sites and thus offers high level support for the design and development of data-intensive web sites. In particular, the OntoWeaver site ontologies comprise two components: a site view ontology and a presentation ontology. The site view ontology provides meta-models to allow for the composition of sophisticated site views, which allow end users to navigate and manipulate the underlying domain databases. The presentation ontology abstracts the look and feel for site views and makes it possible for the visual appearance and layout to be specified at a high level of abstractio

Prototyping Information Visualization in 3D City Models: a Model-based Approach

When creating 3D city models, selecting relevant visualization techniques is a particularly difficult user interface design task. A first obstacle is that current geodata-oriented tools, e.g. ArcGIS, have limited 3D capabilities and limited sets of visualization techniques. Another important obstacle is the lack of unified description of information visualization techniques for 3D city models. If many techniques have been devised for different types of data or information (wind flows, air quality fields, historic or legal texts, etc.) they are generally described in articles, and not really formalized. In this paper we address the problem of visualizing information in (rich) 3D city models by presenting a model-based approach for the rapid prototyping of visualization techniques. We propose to represent visualization techniques as the composition of graph transformations. We show that these transformations can be specified with SPARQL construction operations over RDF graphs. These specifications can then be used in a prototype generator to produce 3D scenes that contain the 3D city model augmented with data represented using the desired technique.Comment: Proc. of 3DGeoInfo 2014 Conference, Dubai, November 201

Segue: Overviewing Evolution Patterns of Egocentric Networks by Interactive Construction of Spatial Layouts

Getting the overall picture of how a large number of ego-networks evolve is a common yet challenging task. Existing techniques often require analysts to inspect the evolution patterns of ego-networks one after another. In this study, we explore an approach that allows analysts to interactively create spatial layouts in which each dot is a dynamic ego-network. These spatial layouts provide overviews of the evolution patterns of ego-networks, thereby revealing different global patterns such as trends, clusters and outliers in evolution patterns. To let analysts interactively construct interpretable spatial layouts, we propose a data transformation pipeline, with which analysts can adjust the spatial layouts and convert dynamic egonetworks into event sequences to aid interpretations of the spatial positions. Based on this transformation pipeline, we developed Segue, a visual analysis system that supports thorough exploration of the evolution patterns of ego-networks. Through two usage scenarios, we demonstrate how analysts can gain insights into the overall evolution patterns of a large collection of ego-networks by interactively creating different spatial layouts.Comment: Published at IEEE Conference on Visual Analytics Science and Technology (IEEE VAST 2018