Programming Languages and Compilers Commons^™

Facets Of R, John M. Chambers

The R Journal

We are seeing today a widespread, and welcome, tendency for non-computer-specialists among statisticians and others to write collections of R functions that organize and communicate their work. Along with the flood of software sometimes comes an attitude that one need-only-learn, or teach, a sort of basic how-to-write-the-function level of R programming, beyond which most of the detail is unimportant or can be absorbed without much discussion. As delusions go, this one is not very objectionable if it encourages participation. Nevertheless, a delusion it is. In fact, functions are only one of a variety of important facets that R has acquired …

Easier Parallel Computing In R With Snowfall And Sfcluster, Jochen Knaus, Christine Porzelius, Harald Binder, Guido Schwarzer

The R Journal

Many statistical analysis tasks in areas such as bioinformatics are computationally very intensive, while lots of them rely on embarrassingly parallel computations (Grama et al., 2003). Multiple computers or even multiple processor cores on standard desktop computers, which are widespread nowadays, can easily contribute to faster analyses.

R itself does not allow parallel execution. There are some existing solutions for R to distribute calculations over many computers — a cluster — for ex ample Rmpi, rpvm, snow, nws or papply. However these solutions require the user to setup and manage the cluster on his own and …

The R Journal (June 2009) 1(1): Complete Issue, The R Foundation

The R Journal

Contributed Research Articles

Facets of R, John M. Chambers

Collaborative Software Development Using R-Forge, Stefan Theußl and Achim Zeileis

Drawing Diagrams with R, Paul Murrell

The hwriter package: Composing HTML Documents with R Objects, Gregoire Pau and Wolfgang Huber

AdMit, David Ardia, Lennart F. Hoogerheide, and Herman K. van Dijk

expert: Modeling Without Data Using Expert Opinion, Vincent Goulet, Michel Jacques, and Mathieu Pigeon

New Numerical Algorithm for Multivariate Normal Probabilities in Package mvtnorm, Xuefei Mi, Tetsuhisa Miwa, and Torsten Hothorn

EMD: A Package for Empirical Mode Decomposition and Hilbert Spectrum, Donghoh Kim, and Hee-Seok Oh

Sample Size Estimation while …

Drawing Diagrams With R, Paul Murrell

The R Journal

R provides a number of well-known high-level facilities for producing sophisticated statistical plots, including the “traditional” plots in the graphics pack age (R Development Core Team, 2008), the Trellis style plots provided by lattice (Sarkar, 2008), and the grammar-of-graphics-inspired approach of ggplot2 (Wickham, 2009). However, R also provides a powerful set of low level graphics facilities for drawing basic shapes and, more importantly, for arranging those shapes relative to each other, which can be used to draw a wide variety of graphical images. This article highlights some of R’s low-level graphics facilities by demonstrating their use in the production of …

Pmml: An Open Standard For Sharing Models, Alex Guazzelli, Michael Zeller, Wen-Ching Lin, Graham Williams

The R Journal

The PMML package exports a variety of predictive and descriptive models from R to the Predictive Model Markup Language (Data Mining Group, 2008). PMML is an XML-based language and has become the de-facto standard to represent not only predictive and descriptive models, but also data pre- and post-processing. In so doing, it allows for the interchange of models among different tools and environments, mostly avoiding proprietary issues and incompatibilities.

The PMML package itself (Williams et al., 2009) was conceived at first as part of Togaware’s data mining toolkit Rattle, the R Analytical Tool To Learn Easily (Williams, 2009). Although it …

A Formal Framework For Modeling And Validating Simulink Diagrams, Chunqing Chen, Jin Song Dong, Jun Sun

Research Collection School Of Computing and Information Systems

Simulink has been widely used in industry to model and simulate embedded systems. With the increasing usage of embedded systems in real-time safety-critical situations, Simulink becomes deficient to analyze (timing) requirements with high-level assurance. In this article, we apply Timed Interval Calculus (TIC), a realtime specification language, to complement Simulink with TIC formal verification capability. We elaborately construct TIC library functions to model Simulink library blocks which are used to compose Simulink diagrams. Next, Simulink diagrams are automatically transformed into TIC models which preserve functional and timing aspects. Important requirements such as timing bounded liveness can be precisely specified in …

The Design And Implementation Of A Safe, Lightweight Haskell Compiler, Timothy Jan Chevalier

Computer Science Faculty Publications and Presentations

Typed programming languages offer safety guarantees that help programmers write correct code, but typical language implementations offer no proof that source-level guarantees extend to executable code. Moreover, typical implementations link programs with unsafe runtime system (RTS) code. I present a compiler for the functional language Haskell that preserves some of the properties of Haskell’s type system. The soundness proof for the combination of the compiler and a verified RTS requires a proof that the compiler emits code that cooperates correctly with the RTS. In particular, the latter proof must address the boundary between the user program and the garbage collector. …

A Survey Of Monge Properties, Swetha Sethumadhavan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Monge properties play an important role in theoretical computer science. Many greedy algorithms are based on such properties, as is speedup in dynamic programming. Monge properties are simple monotonicity properties which are observed and used in various settings such as resource optimization, computational geometry, statistical sampling, computational biology and coding.

Python As A Teaching Tool, Jason Schultz

Honors Capstones

Capstone submitted as a graduate requirement for the BSU Honors Program.

Algorithms For Vertex-Weighted Matching In Graphs, Mahantesh Halappanavar

Computer Science Theses & Dissertations

A matching M in a graph is a subset of edges such that no two edges in M are incident on the same vertex. Matching is a fundamental combinatorial problem that has applications in many contexts: high-performance computing, bioinformatics, network switch design, web technologies, etc. Examples in the first context include sparse linear systems of equations, where matchings are used to place large matrix elements on or close to the diagonal, to compute the block triangular decomposition of sparse matrices, to construct sparse bases for the null space or column space of under-determined matrices, and to coarsen graphs in multi-level …

Pat: Towards Flexible Verification Under Fairness, Jun Sun, Yang Liu, Jin Song Dong, Jun Pang

Research Collection School Of Computing and Information Systems

Recent development on distributed systems has shown that a variety of fairness constraints (some of which are only recently defined) play vital roles in designing self-stabilizing population protocols. Current practice of system analysis is, however, deficient under fairness. In this work, we present PAT, a toolkit for flexible and efficient system analysis under fairness. A unified algorithm is proposed to model check systems with a variety of fairness effectively in two different settings. Empirical evaluation shows that PAT complements existing model checkers in terms of fairness. We report that previously unknown bugs have been revealed using PAT against systems functioning …

Squeak By Example, Andrew P. Black, Stéphane Ducasse, Oscar Nierstrasz, Damien Pollet, Damien Cassou, Marcus Denker

Computer Science Faculty Publications and Presentations

Squeak is a modern open-source development environment for the classic Smalltalk-80 programming language. This book, intended for both students and developers, will guide you gently through the language and tools by means of a series of examples and exercises.

Additional material is available from the book's web page at SqueakByExample.org.

User Interface Design, Moritz Stefaner, Sebastien Ferre, Saverio Perugini, Jonathan Koren, Yi Zhang

Computer Science Faculty Publications

As detailed in Chap. 1, system implementations for dynamic taxonomies and faceted search allow a wide range of query possibilities on the data. Only when these are made accessible by appropriate user interfaces, the resulting applications can support a variety of search, browsing and analysis tasks. User interface design in this area is confronted with specific challenges. This chapter presents an overview of both established and novel principles and solutions.

An Investigation Into Student Reactions Towards Rad Versus Traditional Programming Environments For Novice Developers, Pansy Colkers

Theses : Honours

The traditional approach to programming using text editors is widely used in many institutions to teach introductory programming. These types of traditional programming environments provide fundamental programming concepts for learning, especially in the context of novice developers. In recent years, teaching institutions have seen a trend towards the introduction of visual "drag-and-drop" rapid application development (RAD) environments for teaching novice programmers. These 'environments capture student interest in programming by allowing the construction of workable programs within a short time frame based on minimal pre-existing coding knowledge. However, some have argued that these visual RAD environments might not be suitable for …

Specifying Reusable Aspects, Neelam Soundarajan, Raffi Khatchadourian

Publications and Research

Aspect-Oriented Programming enables developers to manage, in a more modular fashion, implementations of crosscutting concerns that might be scattered or tangled if aspect-oriented techniques were not utilized. Our interest in this paper is in considering techniques for specifying precise properties of aspects. In particular, we are interested in specifying reusable aspects; i.e., aspects that correspond to crosscutting concerns that occur in many systems. These abstract aspects can be reused in various systems where a particular concern is applicable. Although there has been work on issues related to reasoning about aspects and the behaviors of aspect-oriented systems, specifying reusable abstract aspects …

A Semiotic Analysis Of Unified Modeling Language Graphical Notations, Keng Siau, Yuhong Tian

Research Collection School Of Computing and Information Systems

Unified modeling language (UML) is the standard modeling language for object-oriented system development. Despite its status as a standard, UML has a fuzzy formal specification and a weak theoretical foundation. Semiotics, the study of signs, provides a good theoretical foundation for UML research because graphical notations (or visual signs) of UML are subjected to the principles of signs. In our research, we use semiotics to study the effectiveness of graphical notations in UML. We hypothesized that the use of iconic signs as UML graphical notations leads to representation that is more accurately interpreted and that arouses fewer connotations than the …