Information visualizations must allow users to browse information spaces and focus quickly on items of interest. Being able to see some representation of the entire information space provides an initial gestalt overview and gives context to support browsing and search tasks. However, the limited number of pixels on the screen constrain the information bandwidth and make it difficult to completely display large information spaces. The Information Mural is a two-dimensional, reduced representation of an entire information space that fits entirely within a display window or screen. The mural creates a miniature version of the information space using visual attributes such as grayscale shading, intensity, color, and pixel size, along with anti-aliased compression techniques. Information Murals can be used as stand-alone visualizations or in global navigational views. We have built several prototypes to demonstrate the use of Information Murals in visualization applications; subject matter ...

Abstract. After two decades of research in parallel tools for performance tuning, why are users still dissatis ed? This paper outlines the human factors issues that determine how performance tools are perceived by users. The information provides insight into why current performance visualizations are not as well received as they should be | and what must be done in order to develop tools that are more closely aligned to user needs and preferences. Speci c mechanisms are suggested for improving three aspects of performance visualizations: how the user explores the performance space, how the user compares di erent aspects of program behavior, and how the user navigates through complex source code. 1 The Performance Tuning Problem For over two decades, a great deal of research e ort has been directed at tools for improving the performance of parallel applications. Signi cant progress has been made, as can be seen by comparing some of the surveys of parallel tools from that time period [22, 23, 2]. Why, then, are parallel performance tools still

This paper investigates the visualization of distributed algorithms. We present a conceptual model and a system, VADE, that realizes this model. Since in asynchronous distributed systems there is no way of knowing (let alone, visualizing) the "real" execution, we show how to generate a visualization which is consistent with the execution of the distributed algorithm. We also present the design and implementation of our system. VADE is designed so that the algorithm runs on the server's machines while the visualization is executed on a web page on the client's machine. Programmers can write animations quickly and easily with the assistant of the VADE's libraries. Keywords: visualization of algorithms, program visualization, algorithm animation, visualization in education, distributed algorithms. 1 INTRODUCTION Algorithm visualization can assist in the design of algorithms, in the debug process, and while teaching algorithms to students and colleagues. When distribution is added to the ...

This paper describes a methodology that provides detailed predictive performance information throughout the software design and implementation cycles. It is structured around a hierarchy of performance models that describe the computing system in terms of its software, parallelization, and hardware components.The methodology is illustrated with an initial implementation, the performance analysis and characterization environment (PACE) system, which provides information concerning execution time, scalability, and resource use. A principal aim of the work is to provide a capability for rapid calculation of relevant performance numbers without sacrificing accuracy

Permission to make digital or hard copies of portions of this work for personal or classroom use is granted provided that the copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. To copy otherwise requires prior specific permission by the publisher mentioned above.

This paper attempts to classify and compare these graph formalisms and notations which provide different information at different stages of parallel program development

INTRODUCTION An underlying goal in the use of high performance systems is to apply the complex resources to achieve rapid application execution times. It is often the case that performance issues are considered late in the application development when major design choices and system choices have already been finalised. Performance tuning tools, including parallel monitoring environments, are useful in these late stages providing a means in which to investigate and visualise the performance effects. However, during the development of an application, certain issues are typically decided upon without reference to their impact on performance (e.g. in the choice of a numerical implementation, or in the choice of a possible mapping to the system). There is a clear need for the study of performance at each and every stage of the development of high performance applications. The aim of a novel prediction toolset PACE (Performance Analysis and Characterisation Environment), presented

This paper describes the design and implementation of a high-level visualization programming system called Viz. Viz was created out of a need to support rapid visualization prototyping in an environment that could be extended by abstractions in the application problem domain. Viz provides this in a programming environment built on a high-level, interactive language (Scheme) that embeds a 3D graphics library (Open Inventor), and that utilizes a data reactive model of visualization operation to capture mechanisms that have been found to be important in visualization design (e.g., constraints, controlled data flow, dynamic analysis, animation). The strength of Viz is in its ability to create non-trivial visualizations rapidly and to construct libraries of 3D graphics functionality easily. Although our original focus was on parallel program and performance data visualization, Viz applies beyond these areas. We show several examples that highlight Viz functionality and the visualization des...

ABSTRACT.......................................................................

Abstract. Parallel tools rely on graphical techniques to improve the quality of user interaction. In this paper, we explore how visualization and direct manipulation can be exploited in parallel tools, in order to improve the naturalness with which the user interacts with a parallel tool. Examples from recent tool research demonstrate that tool displays can be made more communicative and more intuitive touse. Visualization methods can be used to organize complex performance data into layers and perspectives that exploit the user's visual searching capabilities. Direct manipulation techniques allow the user to focus on key elements and then transition smoothly to further levels of detail or interrelated aspects of program behavior. Heuristics derived from studies with parallel users are proposed for when and how the techniques can be applied more e ectively. 1