We built a tool to visualize and explore program execution traces. Our goal was to help programmers without any prior knowledge of a program, quickly get enough knowledge about its structure so that they can make small to medium changes. In the process, a number of problems were faced and tackled concerning the efficient use of screen space, interaction with multiple concurrent views, and linking of asymmetric views
In our work, we focus on how resource allocation can benefit from visualization. In this paper, we present the main visualization techniques used in a bandwidth allocation system for the management of circuit-switched networks
Information visualization displays can hold a limited number of data points, typically a few thousand, before they get crowded. One way to solve this problem with larger data sets is to create aggregates. Aggregations were used together with the Snap-Together Visualization system to coordinate the visual displays of aggregates and their content. If two displays each hold one thousand items then rapid access and visibility can be maintained for a million points. This paper presents examples based on a database of highway incident data.
An image browser for the exploration of image collections is described The approach taken is to utilize VR input devices to develop more intuitive interaction metaphors that allow users to navigate through large collections of images. The browser presents query results as a strip of images and interaction with the strip is realized by interpreting the user's head movements. The browser is used as a front end to a visual information retrieval system.
Complex information systems are very difficult to represent and users often have problems to find relevant information; this is the case with Web navigation: users feel “lost”. Data contained in such systems can often be organized hierarchically, thus it is possible to represent it as a tree. However, most visualizations are cluttered because of the amount of information to display. We propose to solve these problems by using Virtual Reality (VR) techniques. After reviewing different 3D visualization methods, we decided to use cone trees. Unfortunately, the enhancement provided by graphic methods is not sufficient when hierarchies are very large; in such cases, trees must be pruned with filtering methods. We chose to structure and manipulate data with the eXtensible Markup Language [19]. XML allows the description and organization of any type of information. In this paper, we show how we implemented these principles in the field of network management (for networks based on Synchronous Digital Hierarchy (SDH) equipment). The application we developed eases navigation in data extracted from the Management Information Base (MIB) and accelerates access to useful information. In the future, we will apply these results to Web navigation.
We present Application Redirection , a novel architecture that lets unmodified Windows applications be hosted in a 3D virtual environment. The result is a platform for experimentation in 3D Information Visualization in which the user retains all familiar productivity tools This paper describes the implementation of Application Redirection, using the Task Gallery to illustrate how it is used
Using inductive learning techniques to construct explanatory models for large, high-dimensional data sets is a useful way to discover useful information. However, these models can be difficult for users to understand. We have developed a set of visualization methods that enable a user to evaluate the quality of learned models, to compare alternative models, and identify ways in which a model might be improved We describe the visualization techniques we have explored, including methods for high-dimensional data space projection, variable/class correlation, instance mapping, and model sampling We show the results of applying these techniques to several models built from a benchmark data set of census data.
The ever-increasing presence of hypertext as a mechanism for browsing information has necessitated study of how to counter usability difficulties inherent to hypertext as a medium. The conjunction of semantically typed links with associated visual behaviours are proposed, as a means to amending typical navigation problems. Types provide structure to the connected information set, enabling users to better conceive of the overall structure, while behaviour, taking the form of key-framed animations from link source to destination, allow users to perceive structural relations. A set of link type and behaviour combinations, or link roles, implemented in Hypercept are outlined
This paper describes our recent findings in the area of using glyph shape to display one or two data dimensions in the visualization of 3D scalar and vector fields In our glyph-based visualization system, each glyph represents a data point in 3D space Visual attributes such as size, orientation, color and transparency can be mapped to data dimensions in the 3D space We are exploring the use of glyph shape as a display dimension, using superquadric superellipses as a means of supplying a parameterizable shape A basic factor in effectively using shape for quantitative visualization is determining how many (and which) superellipse shapes people can distinguish Since the superquadric shape's parameter set is not perceptually linear, we conducted a user study to which shapes people can generally distinguish The findings show that with large superellipses, about 22 separate shapes can be distinguished on average These results provide the foundation for exploring how effective superellipses may be in quantitative shape visualization
This paper presents an interactive video visualization system. In this visualization video data is considered to be a block of three dimensional data where frames of video data comprise the third dimension. The user can manipulate and see a cut plane through the video data. The visualization leads to images that are aesthetically interesting as well as being useful for image analysis
We introduce a graphic primitive, called a dimensional anchor (DA), which facilitates the creation of new visualizations and provides insight into the analysis of information visualizations. The DA represents an attempt to provide a unified framework or model for a variety of visualizations, including Parallel Coordinates, scatter plot matrices, Radviz, Survey Plots and Circle Segments A dimensional anchor is constructed by assigning values to parameters associated with various geometric graphic elements that encode the basics of the above visualizations. We define a visualization vector space in which all of the above visualizations and many new ones are represented by vectors. These encodings make it possible to perform a Grand Tour traveling from Parallel Coordinates to Survey Plot, and visiting many other visualizations in between
Virtual Environments (VEs) have the potential to revolutionize traditional product design by enabling the transition from conventional CAD to fully digital product development The presented prototype system targets closing the ** digital gap” as introduced by the need for physical models such as clay models or mockups in the traditional product design and evaluation cycle. We describe a design environment that provides an intuitive human-machine interface for the creation and manipulation of three-dimensional (3D) models in a semi-immersive design space, focussing on ease of use and increased productivity for both designer and CAD engineers
This paper presents work in progress on our approach to visualizing multi-dimensional and hierarchical information. We propose two new graphical user interfaces, the Magic Eye View (MEV) and ShapeVis to explore information spaces. In order to cope with large information sets we combine MEV and ShapeVis with dynamic hierarchical clustering of information units The Magic Eye View, which implements a new Focus+Context technique, is used as the interface for visualizing those hierarchies. In order to support detailed exploration of the information space (e.g analysis of certain cluster nodes or hierarchy levels) a new technique for visualizing multidimensional information is used. ShapeVis provides 2D or 3D representations of the information objects according to the selected subset of the information space Objects are represented as small closed free-form-surfaces. The location, size and shape of these surfaces describe the original objects in the information space uniquely according to their properties
Virtual environment (VE) technologies have considerable potential to extend the power of information visualization methods, and those of scientific visualization more broadly. Our specific focus here is on VE technologies as a medium for geographic visualization and on some of the challenges that must be addressed if the potential of VE is to be realized in this context.
Scheduling, routing, and layout tasks are examples of hard operations-research problems that have broad application in industry. Typical algorithms for these problems combine some form of gradient descent to find local minima with some strategy for escaping nonoptimal local minima and traversing the search space. Our idea is to divide these two subtasks cleanly between human and computer: in our paradigm of human-guided sample search the computer is responsible only for finding local minima using a simple search method; using information visualization, the human identifies promising regions of the search space for the computer to explore, and also intervenes to help it escape nonoptimal local minima. This is a specific example of a more general strategy, that of combining heuristic-search and information-visualization techniques in an interactive system. We are applying our approach to the problem of capacitated vehicle routing with time windows (CVRTW). We describe the design and implementation of our initial prototype, some preliminary results, and our plans for future work.
In this work, we present our experience of utilizing audio-visual data mappings for GIS-based information visualization. The application we choose is a GIS-based system for visualizing crime in a city. In this application, we enhance the pseudo-colored visual presentation of crime information by mapping data to several sound parameters — volume, balance, bass and treble. Our motivation for choosing sound in addition to vision is guided by our belief that data quantities mapped to various colors in a coloring scheme do not always clearly describe the information being presented for many different tasks that visualization is expected to support In many cases additional data characteristics can be conveyed to the user through sound to enhance the performance of the user on those tasks. We have conducted experiments with human users to compare the performance of users on visual data mapping alone vs. visual and sound data mappings together on several tasks including estimates of raw data values, local averaging, and global comparison. In most cases, we found that the use of bi-modal visual and sound data mappings together provided more accurate understanding of data displays
The rapid proliferation and growth of database management systems has resulted in the retention of massive amounts of information for data processing and analysis needs. Many data processing requirements can be satisfied through the use of traditional database languages, such as SQL. These languages retrieve and present query results in record-oriented tables. The table of records format is best for presenting every record, but it cannot give a feel for the overall character of the data set.
Locating relevant information on the Internet is a challenging task. The use of commercial search engines such as Altavista and Hotbot simplify the problem [2], however, an user may scan many pages before finding a relevant document. This process is tedious and users may miss important documents if insufficient information is retrieved from a search engine. We have developed a set of tools to collect, organize, and display information from the Internet. Our tools range from experimental visualizations to a working prototype with multiple users. The tools reduce the time to obtain relevant information by automating the collection and organization of data.
