Jarke J. van Wijk

Eindhoven University of Technology | TUE · Department of Mathematics and Computer Science

We conducted the RATE-Analytics project: a unique collaboration between Rabobank, Achmea, Tilburg and Eindhoven University. We aimed to develop foundations and techniques for next generation big data analytics. The main challenge of existing approaches is the lack of reliability and trustworthiness: if experts do not trust a model or its prediction...

Network data is ubiquitous; e-mail traffic between persons, telecommunication, transport and financial networks are some examples. Often these networks are large and multivariate, besides the topological structure of the network, multivariate data on the nodes and links is available. Currently, exploration and analysis methods are focused on a sing...

In safety and security domains where objects of interest (OOI), such as people, vessels, or transactions, are continuously monitored, automated reasoning is required due to their sheer number and volume of information. We present a method to visually explain the rationale of a reasoning engine that raises an alarm if a certain situation is reached....

Fig. 1. The visual matrix is a central element in our visual analytics multiple coordinated view approach for the exploration and analysis of massive mobile phone data. On the left, geographical visualization of Senegal divided into 123 arrondissements that contain a total of 1666 cell towers, shown as white dots (correlating with population densit...

Fig. 1. The visual matrix is a central element in our visual analytics multiple coordinated view approach for the exploration and analysis of massive mobile phone data. On the left, geographical visualization of Senegal divided into 123 arrondissements that contain a total of 1666 cell towers, shown as white dots (correlating with population densit...

In moving object visualization, objects and their attributes are commonly represented by glyphs on a geographic map. In areas on the map densely populated by these objects, visual clutter and occlusion of glyphs occur. We propose a method to solve this problem by partitioning the set of all objects into subsets that are each visualized using an agg...

We present a visualization method for the interactive exploration of predicted positions of moving objects, in particular, ocean-faring vessels. Two simple prediction models, one based on similarity to historical trajectories and one on Monte Carlo simulation, are presented. The prediction models generate temporal probability density fields startin...

Networks are present in many fields such as finance, sociology, and transportation. Often these networks are dynamic: they have a structural as well as a temporal aspect. In addition to relations occurring over time, node information is frequently present such as hierarchical structure or time-series data. We present a technique that extends the Ma...

The visualization group of TU/e has worked on information visualization since 1998. In this talk I will give an overview of our work on tree, graph, and multivariate visualization, for a variety of applications, including software visualization. Techniques like cushion treemaps, squarified treemaps, hierarchical edge bundles, and flexible linked ax...

We present a novel visual exploration method based on small multiples and large singles for effective and efficient data analysis. Users are enabled to explore the state space by offering multiple alternatives from the current state. Users can then select the alternative of choice and continue the analysis. Furthermore, the intermediate steps in th...

Networks are present in many fields such as finance, sociology, and transportation. Often these networks are dynamic: they have a structural as well as a temporal aspect. We present a technique that extends the Massive Sequence View (MSV) for the analysis of the temporal and structural aspects of dynamic networks. Using features in the data as well...

We present a system for the exploration and analysis of massive mobile phone data that enables users to gain insight. First we identify user tasks and develop a system following a visual analytics approach by tightly integrating visualization, interaction and algorithmic support. The system is then evaluated by exploring a massive mobile phone data...

We discuss methods to visualize large amounts of object movements described with so called multivariate trajectories, which are lists of records with multiple attribute values about the state of the object. In this chapter we focus on vessel traffic as one of the examples of this kind of data. The purpose of our visualizations is to reveal what has...

Multivariate data visualization is a classic topic, for which many solutions have been proposed, each with its own strengths and weaknesses. In standard solutions the structure of the visualization is fixed, we explore how to give the user more freedom to define visualizations. Our new approach is based on the usage of Flexible Linked Axes: The use...

We consider moving objects as multivariate time-series. By visually analyzing the attributes, patterns may appear that explain why certain movements have occurred. Density maps as proposed by Scheepens et al. [25] are a way to reveal these patterns by means of aggregations of filtered subsets of trajectories. Since filtering is often not sufficient...

There are many visualizations that show the trajectory of a moving object to obtain insights in its behavior. In this user study, we test the performance of three of these visualizations with respect to three movement features that occur in vessel behavior. Our goal is to compare the recently presented vessel density by Willems et al. [WvdWvW09] wi...

We present a method to interactively explore multiple attributes in trajectory data using density maps, i.e., images that show an aggregate overview of massive amounts of data. So far, density maps have mainly been used to visualize single attributes. Density maps are created in a two-way procedure; first smoothed trajectories are aggregated in a d...

We present the results of a study comparing five directed-edge representations for use in 2D, screen-based node-link diagrams. The goal of this work is to extend the understanding of tradeoffs and best practices for the representation of edges in directed graphs and to help practitioners choose among different options. Our work applies to graphs in...

We present the results of a study comparing three directed-edge representations in node-link diagrams. Node-link diagrams are probably the most popular type of graph representations; nodes are depicted as dots and links as straight or curved lines connecting the nodes. An arrowhead placed at the end point of a link is traditionally used to indicate...

Parallel coordinate plots (PCPs) are a well-known visualization technique for viewing multivariate data. In the past, various visual modifications to PCPs have been proposed to facilitate tasks such as correlation and cluster identification, to reduce visual clutter, and to increase their information throughput. Most modifications pertain to the us...

When users want to continue an analysis performed in the past, done by themselves or by a collaborator, they need an overview of what has been done and found so far. Such an overview helps them to gain a shared knowledge about each others’ analysis strategy and continue the analysis. We aim to support users in this process, and thereby support thei...

Information visualization is a user-centered design discipline. In this article we argue, however, that designing information visualization techniques often requires more than designing for user requirements. Additionally, the data that are to be visualized must also be carefully considered. An approach based on both the user and their data is enca...

Graphs depicted as node-link diagrams are widely used to show relationships between entities. However, node- link diagrams comprised of a large number of nodes and edges often suffer from visual clutter. The use of edge bundling remedies this and reveals high-level edge patterns. Previous methods require the graph to contain a hierarchy for this, o...

We propose a geographical visualization to support operators of coastal surveillance systems and decision making analysts to get insights in vessel movements. For a possibly unknown area, they want to know where significant maritime areas, like highways and anchoring zones, are located. We show these features as an overlay on a map. As source data...

Graphs are often visualized using node-link representa- tions: vertices are depicted as dots, edges are depicted as (poly)lines connecting two vertices. A directed edge run- ning from vertex A to B is generally visualized using an arrow representation: a (poly)line with a triangular arrow- head at vertex B. Although this representation is intuitive...

An important part of many software maintenance tasks is to gain a sufficient level of understanding of the system at hand. The use of dynamic information to aid in this software understanding process is a common practice nowadays. A major issue in this context is scalability: due to the vast amounts of information, it is a very difficult task to su...

Researchers and users of Information Visualization are convinced that it has value. This value can easily be communicated to others in a face-to-face setting, such that this value is experienced in practice. To convince broader audiences, and also, to understand the intrinsic qualities of visualization is more difficult, however. In this paper we c...

We provide a novel visualization method for the comparison of hierarchically organized data. Our technique visualizes a pair of hierarchies that are to be compared and simultaneously depicts how these hierarchies are related by explicitly visualizing the relations between matching subhierarchies. Elements that are unique to each hierarchy are shown...

Abstract Most graph visualization techniques focus on the structure of graphs and do not offer support for dealing with node attributes and edge labels. To enable users to detect relations and patterns in terms of data associated with nodes and edges, we present a technique where this data plays a more central role. Nodes and edges are clustered ba...

We present a new method for the visual analysis of multivariate system traces. Our method combines three perspectives: (1) a schematic diagram, (2) time series plots and (3) a state transition graph. After we show how these perspectives are related, we discuss their integration into a single solution for the visual analysis of multivariate system t...

State spaces are commonly used representations of system behavior. A state space may be derived from a model of system behavior but can also be obtained through process mining. For a good understanding of the system's behavior, an analyst may need to assess the state space. Unfortunately, state spaces of realistic applications tend to be very large...

Analysts of computer-based systems often face large data sets, such as those represented in state transition graphs, in which the organizational structure is clear but interpreting the data is not. This new method lets users generate interactive visualizations that help them analyze systems more easily, accurately, and quickly. Computer scientists...

The use of dynamic information to aid in software understanding is a common practice nowadays. One of the many approaches concerns the comprehension of execution traces. A major issue in this context is scalability: due to the vast amounts of information, it is a very difficult task to successfully find your way through such traces without getting...

The aim of visualization is to enable users to obtain insight, and not just to produce images. Hence, if we want to make progress in the field of visualization, close cooperation with users is essential, but such cooperation is not without problems. There are two major gaps to be bridged. First, there's a knowledge gap between the visualization exp...

Color is routinely used to visualize interval and ordinal data, while texture is not. For color, a variety of perceptually based models is available, which can be used to convey data via straightforward mapping. The dimensionality of texture is less well understood and there are almost no perceptually based and validated models available to generat...

We present a new approach for the visual analysis of state transition graphs. We deal with multivariate graphs where a number of attributes are associated with every node. Our method provides an interactive attribute-based clustering facility. Clustering results in metric, hierarchical and relational data, represented in a single visualization. To...

The field of visualization is maturing. Many problems have been solved and new directions are sought. In order to make good choices, an understanding of the purpose and meaning of visualization is needed. In this paper, visualization is considered from multiple points of view. First, a technological viewpoint is adopted, where the value of visualiz...

The genus of a knot or link can be defined via Seifert surfaces. A Seifert surface of a knot or link is an oriented surface whose boundary coincides with that knot or link. Schematic images of these surfaces are shown in every text book on knot theory, but from these it is hard to understand their shape and structure. In this paper, the visualizati...

The software package DNAVis offers a fast, interactive and real-time visualization of DNA sequences and their comparative genome annotations. DNAVis implements advanced methods of information visualization such as linked views, perspective walls and semantic zooming, in addition to the display of heterologous data in dot plot-like matrix views. Ava...

The traditional cycle in simulation is to prepare input, execute a simulation, and to visualize the results as a post-processing step. However, more insight and a higher productivity can be achieved if these activities are done simultaneously. This is the underlying idea of Computational Steering: researchers change parameters of their simulation o...

The visualization techniques used in current soft-ware visualization frameworks make use of a limited set of graphical elements to highlight relevant aspects of a software system. Typical examples of such el-ements are text, simple geometric shapes and uni-form color fills. Although human visual perception enables rapid processing of additional vis...

The genus of a knot or link can be defined via Seifert surfaces. A Seifert surface of a knot or link is an oriented surface whose boundary coincides with that, knot or link. Schematic images of these surfaces are shown in every text book on knot theory, but from these it is hard to understand their shape and structure. In this paper the visualizati...

The visualization techniques used in current software vi- sualization frameworks make use of a limited set of graphi- cal elements to highlight relevant aspects of a software sys- tem. Typical examples of such elements are text, simple geometric shapes and uniform color fills. Although human visual perception enables rapid processing of additional...

Transition systems are graphs and it is natural to consider their visual representation as a graph visualization problem. They also pose an interesting multidimensional visualization challenge since every state may be considered as a point in n-space. We discuss a number of approaches toward projecting transition systems to the 2D plane by consider...

Large 2D information spaces, such as maps, images, or abstract visualizations, require views at various level of detail: close ups to inspect details, overviews to maintain (literally) an overview. Users often change their view during a session. Smooth animations enable the user to maintain an overview during interactive viewing and to understand t...

DNA sequences and their annotations form ever expanding data sets. Proper explorations of such data sets require new tools for visualization and analysis. In this case study, we have dened the requirements for a visualization tool for annotated DNA sequences. We have implemented these requirements in a new and e xible tool for browsing and comparin...

Many real world graphs have small world characteristics, that is, they have a small diameter compared to the number of nodes and exhibit a local cluster structure. Examples are social networks, software structures, bibliographic references and biological neural nets. Their high connectivity makes both finding a pleasing layout and a suitable cluste...

Computational steering is the ultimate goal of interactive simulation. Steering enables users to supervise and dynamically control the computation of an ongoing simulation. We describe CSE: a modular architecture for a computational steering environment. The kernel of the architecture is designed to be very simple, flexible and minimalistic. All hi...

INTRODUCTION Visual supercomputing has become a hot topic. Both simulation and visualization have boosted in recent years. Many methods, techniques and tools are available nowadays for the simulation and visualization of complex phenomena. Current computing hardware enables researchers and engineers to perform complex simulations within seconds. Th...

Computational Steering is the ultimate goal of interactive simulation: researchers change parameters of their simulation and immediately receive feedback on the effect. We present a general and flexible environment for computational steering. Within this environment a researcher can easily develop user interfaces and 2-D visualizations of his simul...

let us try to make synthetic images, using a wide variety of visual cues to transfer information as efficiently and effectively as possible. Tree Visualization We are obviously not the first to try to visualize trees. The graphical presentation of tree structures has long been studied in the graph drawing community [7]. A stanCOMMUNICATIONS OFTHEAC...

Beamtrees are a new method for the visualization of large hierarchical data sets, such as directory structures and organization structures. Nodes are shown as stacked circular beams such that both the hierarchical structure as well as the size of nodes are depicted. The dimensions of beams are calculated using a variation of the treemap algorithm....

A new method for the visualization of state transition systems is presented. Visual information is reduced by clustering nodes, forming a tree structure of related clusters. This structure is visualized in three dimensions with concepts from cone trees and emphasis on symmetry. A number of interactive options are provided as well, allowing the user...

Large 2D information spaces, such as maps, images, or abstract vi- sualizations, require views at various level of detail: Close ups to inspect details, overviews to maintain (literally) an overview. Users often switch between these views. We discuss how smooth ani- mations from one view to another can be defined. To this end, a metric on the effec...

A wide variety of drawing packages is available for architectural design. However, most of these systems are oriented to the production of final technical drawings, and only few support the early phase of design. In this paper, we present a new approach for a design system to support this phase. The method is based on a framework from architecture...

A new method for the visualization of state transition systems is presented. Visual information is reduced by clustering nodes, forming a tree structure of related clusters. This structure is visualized in three dimensions with concepts from cone trees and emphasis on symmetry. A number of interactive options are provided as well, allowing the user...

Beamtrees are a new method for the visualization of large hierarchical data sets. Nodes are shown as stacked circular beams, such that both the hierarchical structure as well as the size of nodes are depicted. The dimensions of beams are calculated using a variation of the treemap algorithm. A small user study indicated that beamtrees are significa...

A new method for the visualization of huge hierarchical data structures is presented. The method is based on the observation that we can easily see the branches, leaves, and their arrangement in a botanical tree, despite of the large number of elements. The strand model of Holton is used to convert an abstract tree into a geometric model. Nonleaf n...

The use of computational steering for smog prediction is de- scribed. This application is representative for many underlying issues found in steering high performance applications: high computing times, large data sets, and many different input parameters.

Logging of input and output variables is very useful in computational steering. In this paper we describe how we added logging functionality to a computational steering environment developed at CWI. We show how a 2D interface can be augmented with logging by using the third dimension for the display of the logged variables. The user specifies which...

Scientists can gain much more insight from their simulations if they are enabled to change simulation parameters on the fly while observing the results immediately. A crucial aspect of such computational steering is an intuitive user interface. We have developed an environment that enables researchers to construct such interfaces efficiently and ef...

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A new method is presented for the visualization of hierarchical information, such as directory structures and organization structures. Cushion treemaps inherit the elegance of standard treemaps: compact, space-filling displays of hierarchical information, based on recursive subdivision of a rectangular image space. Intuitive shading is used to prov...

Scientists can gain much more insight from their simulations if they are enabled to change simulation parameters on the fly while observing the results immediately. A crucial aspect of such computational steering is an intuitive user interface. We have developed an environment that enables researchers to construct such interfaces efficiently and ef...

Computational steering is a powerful concept that allows scientists to interactively control a computational process during its execution. In this paper, a survey of computational steering environments for the on-line steering of ongoing scientific and engineering simulations is presented. These environments can be used to create steerable applicat...

Rendering objects transparently gives additional insight in complex and overlapping structures. However, traditional techniques for the rendering of transparent objects such as alpha blending are not very well suited for the rendering of multiple transparent objects in dynamic scenes. Screen door transparency is a technique to render transparent ob...

We present a method for the definition of multiple views in 3D interfaces for computational steering. The method uses the concept of a point-based parametrizable camera object. This concept enables a user to create and configure multiple views on his custom 3D interface in an intuitive graphical manner. Each view can be coupled to objects present i...

The use of computational steering for smog prediction is described. This application is representative for many underlying issues found in steering high performance applications: high computing times, large data sets, and many different input parameters. After a short description of the smog prediction model, its visualization and steering are desc...

Computational steering is a technique that combines simulation and visualization. The user is continuously provided with visual feedback about the state of the simulation, and can change parameters on the fly. Designers can vary parameters to optimize their product, users can detect errors in the input early, researchers can do qualitative sensitiv...

We present a system where visualization and the control of the simulation are integrated to facilitate interactive exploration and modeling of large data sets. The system was developed to estimate properties of the atmosphere of Venus from comparison between measured and simulated data. Reuse of results, distributed computing, and multiple views on...

The use of computational steering for smog prediction is described. This application is representative for many underlying issues found in steering high performance applications: high computing times, large data sets, and many different input parameters. After a short description of the smog prediction model, its visualization and steering are desc...

The aim of computational steering is to provide researchers more insight in simulations by enabling them to change parameters on the fly and to observe the result immediately. In practice, however, the development of computational steering applications requires considerable expertise in a wide variety of disciplines. In this paper we present a comp...

this article we present two extensions to the HyperSlice and show how the method can be used in practice. 1. Introduction

Computational Steering is the ultimate goal of interactive simulation: researchers change parameters of their simulation and immediately receive feedback on the effect. We present a general and flexible graphics tool that is part of an environment for Computational Steering developed at CWI. It enables the researcher to interactively develop his ow...

The traditional cycle in simulation is to prepare input, execute a simulation, and to visualize the results as a post-processing step. However, more insight and a higher productivity can be achieved if these activities are done simultaneously. This is the underlying idea of computational steering: researchers change parameters of their simulation o...

Computational steering is the ultimate goal of interactive simulation. Steering enables users to supervise and dynamically control the computation of an ongoing simulation. We describe CSE : a modular architecture for a computational steering environment. The kernel of the architecture is designed to be very simple, flexible and minimalistic. All h...

Computational steering is the ultimate goal of interactive simulation. Steering enables users to supervise and dynamically control the computation of an ongoing simulation. We describe CSE: a modular architecture for a computational steering environment. The kernel of the architecture is designed to be very simple, flexible and minimalistic. All hi...