Jeffrey D. McWhirter

Escalante: an environment for the rapid construction of visual language applications

The paper describes Escalante, an environment that supports the iterative design, rapid prototyping and generation of complex visual language applications. Escalante enables the developer to visually specify and generate applications for a wide variety of graph based visual languages. A set of example applications are presented that serve to demonstrate the range of languages to which Escalante is applicable.<<ETX>>

Extensible parallel program performance visualization

Performance bugs have classically been difficult to identify in high performance programs. The problem arises because there is a broad spectrum of causes of performance degradation, and because it may be necessary to apply specialized diagnostics to search the performance space. The prototype tuning environment we are developing enables one to explore the performance space of a program using customized performance visualization techniques. It addresses the breadth problem by providing tools known to be useful for broad explorations, tools for inspecting specific performance bugs, and an ability to extend the observation platform by custom analysis and visualization. This paper describes the ParaVision tool that enables one to integrate various PICL-based performance tools into a single user environment.<<ETX>>

AlgorithmExplorer: a student centered algorithm animation system

Algorithm animation can be an effective tool for understanding the behavior of programs. However, most approaches towards algorithm animation have focused on evermore sophisticated graphical depictions of programs, and not on the process of how students can develop and make use of animations in an educational setting. We describe the AlgorithmExplorer, a flexible algorithm animation system targeted towards classroom, laboratory and individual student use. The AlgorithmExplorer provides an open system architecture for integrating student programs, mechanisms for supporting user input, and a three tiered animation command interface that provides rich animation constructs while also supporting a wide range of student programming abilities.

Style-based cut-and-paste in graphical editors

Although great strides have been made in the last 10–15 years in the development of systems that use graphical representations, very little work has been done in developing systems that help users edit diagrams efficiently. This paper addresses the design of one such feature of a graphical editor, namely cut and paste. We show how knowledge of the syntax and semantics of the language being edited allows us to design a more intelligent cut-and-paste facility.

A characterization framework for visual languages

The general goal of this research is to facilitate the development of visual language environments for the class of visual languages that are based on graph models. The approach the authors take relies on a conceptual framework to define general model components and behaviors; any particular language is defined by selecting and enhancing components and behaviors within the framework. The objective is to provide a system, based on the conceptual framework, in which the language designer defines a data model in conjunction with a distinct, but related, representation of the model. The language specific modules of the resulting visual language system are generated from the specification. These language modules can be viewed as system independent abstract data types which are placed into a fixed system environment. This work enables the visual language developer to easily experiment with different aspects of a visual language. It also provides a basis for the development of, and experimentation with, mechanisms used to support the use of complex visual languages and their environments. The authors address the issue of usability and language complexity by providing support for the development of mechanisms such as visual abstraction hierarchies, multiple views, multiple windows, language component filtering, etc.<<ETX>>

Diagram entry mechanisms in graphical environments

Although great strides have been made in the last 10-15 years in the development of systems that use graphical representations, very little work has been done in developing systems that help users input and edit diagrams efficiently. This paper describes an ongoing project addressing the design of one such feature of a graphical editor: diagram entry. We show how knowledge of the syntax and semantics of the language being edited allows us to design a more intelligent diagram entry facility.

Generation of visual language environments

In many problem domains visual languages are an importam media for user/computer communication. A visual language environment (or editor) is a system that supporls the creation and manipulation of instances of a particular visual language. This paper introduces the .Esca/ante system, which facilitates development of, and expenmentaI mn with, highly functional environments for graph-based visual languages by supporting their specification and au-

Building dynamic graphical interfaces with Escalante

The development of dynamic graphical applications is a difficult and time consuming task. This difficulty stems from the complexity of the applications as well as the lack of adequate development tools. Escalante is an environment that supports the visual specification, rapid prototyping and generation of complex graphical applications. Using Escalante, one can rapidly construct a broad range of highly functional applications with a minimal amount of manual programming.

VGrep: a graphical tool for the exploration of textural documents

Discovering the content and structure of textual files through keyword based search is a common task of computer users. However, the results of such a search is often difficult to understand and to use. This paper describes VGrep, a tool that facilitates keyword based search through large textual documents. VGrep provides the ability to formulate queries and present the results of the queries in an abstract graphical representation. KEVWORDS Word search, visualization. INTRODUCTION One of the common tasks that programmers and other users of computers engage in is to search the contents of a set of files for particulrw key words or strings. The result of such a search is typically in a linear textual format listing the files and the lines that contained the search expression. For a small number of matches this output is sufficient for most tasks. However, as the number of matches grows, understanding the information being presented becomes more difficult. Furthermore, navigating through the set of files can be a convoluted task requiring the user to engage in a series of steps (e.g., identifying the line, bringing up a text viewer for the file, and going to the line number that is displayed in the search output). VGrep is a tool that supports keyword based search and navigation of the results of the search. In this paper we first present an example textually oriented search and then describe how VGrep is used to facilitate this search process. Example We now discuss a typical scenario of the use of grep, a Unix search command. Suppose a programmer needs to search for the keyword ibbox in a set of program source files. The search command might look like this: grep -i -n ibbox * .C which causes all of the files ending in .C to be searched in a non-case sensitive manner for the string “ibbox”. The output is to include the line numbers. Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the ,4Cfvf copyright notice and the title of the publication and its date appear, and notice is given that copying is by permission of ACM. To copy otherwise, or to republish, requires a fee and/or specific permission. CHI Companion 95, Denver, Colorado, USA

A demonstration of interactive graph based visual language applications

Escalante is a development environment for applications that use the pictorial representations of graphs to facilitate human-computer communication. Escalante supports a wide range of graph representations and layouts through a localized spatial constraint mechanism as well as external graph layout tools.