RGtk2: A Graphical User Interface Toolkit for R

Graphical user interfaces (GUIs) are growing in popularity as a complement or alternative to the traditional command line interfaces to R. RGtk2 is an R package for creating GUIs in R. The package provides programmatic access to GTK+ 2.0, an open-source GUI toolkit written in C. To construct a GUI, the R programmer calls RGtk2 functions that map to functions in the underlying GTK+ library. This paper introduces the basic concepts underlying GTK+ and explains how to use RGtk2 to construct GUIs from R. The tutorial is based on simple and pratical programming examples. We also provide more complex examples illustrating the advanced features of the package. The design of the RGtk2 API and the low-level interface from R to GTK+ are discussed at length. We compare RGtk2 to alternative GUI toolkits for R.

Statistical user interfaces

A statistical user interface is an interface between a human user and a statistical software package. Whenever we use a statistical software package we want to solve a specific statistical problem. But very often at first it is necessary to learn specific things about the software package. Everyone of us knows about the ?religious wars? concerning the question which statistical software package/method is the best for a certain task; see Marron (1996) and Cleveland and Loader (1996) and related internet discussions. Experienced statisticians use a bunch of different statistical software packages rather than a single one; although all of the major companies (at least the marketing departments) tell us that we only need their software package. --

Integrated modeling tool for performance engineering of complex computer systems

This report summarizes Advanced System Technologies' accomplishments on the Phase 2 SBIR contract NAS7-995. The technical objectives of the report are: (1) to develop an evaluation version of a graphical, integrated modeling language according to the specification resulting from the Phase 2 research; and (2) to determine the degree to which the language meets its objectives by evaluating ease of use, utility of two sets of performance predictions, and the power of the language constructs. The technical approach followed to meet these objectives was to design, develop, and test an evaluation prototype of a graphical, performance prediction tool. The utility of the prototype was then evaluated by applying it to a variety of test cases found in the literature and in AST case histories. Numerous models were constructed and successfully tested. The major conclusion of this Phase 2 SBIR research and development effort is that complex, real-time computer systems can be specified in a non-procedural manner using combinations of icons, windows, menus, and dialogs. Such a specification technique provides an interface that system designers and architects find natural and easy to use. In addition, PEDESTAL's multiview approach provides system engineers with the capability to perform the trade-offs necessary to produce a design that meets timing performance requirements. Sample system designs analyzed during the development effort showed that models could be constructed in a fraction of the time required by non-visual system design capture tools

Genetic algorithms

Genetic algorithms are mathematical, highly parallel, adaptive search procedures (i.e., problem solving methods) based loosely on the processes of natural genetics and Darwinian survival of the fittest. Basic genetic algorithms concepts are introduced, genetic algorithm applications are introduced, and results are presented from a project to develop a software tool that will enable the widespread use of genetic algorithm technology

User's manual for MacPASCO

A user's manual is presented for MacPASCO, which is an interactive, graphic, preprocessor for panel design. MacPASCO creates input for PASCO, an existing computer code for structural analysis and sizing of longitudinally stiffened composite panels. MacPASCO provides a graphical user interface which simplifies the specification of panel geometry and reduces user input errors. The user draws the initial structural geometry and reduces user input errors. The user draws the initial structural geometry on the computer screen, then uses a combination of graphic and text inputs to: refine the structural geometry; specify information required for analysis such as panel load and boundary conditions; and define design variables and constraints for minimum mass optimization. Only the use of MacPASCO is described, since the use of PASCO has been documented elsewhere

SPACES - An Integrated Software Approach for Attitude Determination, Control and Pointing Systems Analysis

The recent success of the Pegasus small satellite launch system by Orbital Sciences Corporation foreshadows radical changes to the satellite industry comparable to those which occurred in the computer industry when personal computers became commercially available alternatives to mainframes. In order to support low cost, fixed price contracts for small commercial satellites, engineering design cycles for satellites and satellite subsystems will have to be shortened, and accomplished with fewer staff to meet more stringent cost and schedule goals. To accomplish this, better design tools must be made available which will allow the mission analysis, requirements analysis, and other systems engineering tasks to be accomplished in an integrated software environment by a systems engineer. The Satellite Pointing and Attitude Control Engineering System (SPACES) is a software package developed as part of an integrated toolset by Honeywell Satellite Systems Operation to meet the need for altitude determination, control and navigation subsystems requirements analysis. SPACES is specifically designed to support initial mission analysis, pointing and tracking system requirements, as well as ACDNS sensor and actuator analyses. The approach used in SPACES was to take advantage of the state-of-the-art in user interface technology to provide a integrated system preliminary design tool that is easy to use with graphically oriented output that can handle a large class of satellite missions without requiring software modification

Redesign of Johar: a framework for developing accessible applications

As the population of disabled people continues to grow, designing accessible applications is still a challenge, since most applications are incompatible with assistive technologies used by disabled people to interact with the computer. This accessibility issue is usually caused by the reluctance of software engineers or developers to include complete accessibility features in their applications, which in turn is often due to the extra cost and development effort required to dynamically adapt applications to a wide range of disabilities. Our aim to resolve accessibility issues led to the design and implementation of the Johar framework, which facilitates the development of applications accessible to both disabled and non-disabled users. In the Johar architectural model, the ability-based front-end user interfaces are called interface interpreters, while the application-specific logic or functionality implemented by application developers are called applications or apps. The seamless interaction between each interface interpreter and app is made possible by Johar. In this thesis, we assure the quality of Johar by detecting and resolving many inconsistencies, omissions, irrelevancies, and other anomalies that can trigger unexpected or abnormal behaviour in Johar, and/or alter the smooth operation of interface interpreters and apps. Our approach to conducting the quality assurance involved reviewing the two components of Johar, johar.gem and johar.idf, by critically examining the functionality of classes in each component, including how classes interrelate and how functions are allocated or distributed among the classes. We also performed an exhaustive comparative review of four documents - IDF Format Specification document, XML Schema Document or XSD, the Interface Interpreter Specification document, and the johar.idf package - which are vital to the smooth running of all interface interpreters and apps. We also developed an automated testing tool in order to determine whether all errors or violations in an IDF (Interface Description File) are detected and reported. As part of this thesis, we designed and implemented an interface interpreter, called Star that presents WIMP (Windows, Icons, Menus, and Pointers) graphical user interfaces to users, which is based on the new version of Johar. This new version evolved as a result of the redesign activities carried out on the Johar components and the various modifications effected during the quality assurance process. We also demonstrated the usage of Star on two apps to prove Johar’s ability to guarantee smooth interaction between interface interpreters and apps. Finally, in this thesis, we designed two other interface interpreters which will be implemented in the near future