Programming Languages and Compilers Commons^™

Levity Polymorphism (Extended Version), Richard A. Eisenberg, Simon Peyton Jones

Computer Science Faculty Research and Scholarship

Parametric polymorphism is one of the lynchpins of modern typed programming. A function that can work seamlessly over a variety of types simplifies code, helps to avoid errors introduced through duplication, and and is easy to maintain. However, polymorphism comes at a very real cost, one that each language with support for polymorphism has paid in different ways. This paper describes this cost, proposes a theoretically simple way to reason about the cost—that kinds, not types, are calling conventions—and details one approach to dealing with polymorphism that works in the context of a language, Haskell, that prizes both efficiency …

Grace's Inheritance, James Noble, Andrew P. Black, Kim B. Bruce, Michael Homer, Timothy Jones

Computer Science Faculty Publications and Presentations

This article is an apologia for the design of inheritance in the Grace educational programming language: it explains how the design of Grace’s inheritance draws from inheritance mechanisms in predecessor languages, and defends that design as the best of the available alternatives. For simplicity, Grace objects are generated from object constructors, like those of Emerald, Lua, and Javascript; for familiarity, the language also provides classes and inheritance, like Simula, Smalltalk and Java. The design question we address is whether or not object constructors can provide an inheritance semantics similar to classes.

A Specification For Dependent Types In Haskell, Stephanie Weirich, Antoine Voizard, Pedro Henrique Azevedo De Amorim, Richard A. Eisenberg

Computer Science Faculty Research and Scholarship

We propose a core semantics for Dependent Haskell, an extension of Haskell with full-spectrum dependent types. Our semantics consists of two related languages. The first is a Curry-style dependently-typed language with nontermination, irrelevant arguments, and equality abstraction. The second, inspired by the Glasgow Haskell Compiler’s core language FC, is its explicitly-typed analogue, suitable for implementation in GHC. All of our results -- chiefly, type safety, along with theorems that relate these two languages -- have been formalized using the Coq proof assistant. Because our work is backwards compatible with Haskell, our type safety proof holds in the presence of nonterminating …

Constrained Type Families, J. Garrett Morris, Richard A. Eisenberg

Computer Science Faculty Research and Scholarship

We present an approach to support partiality in type-level computation without compromising expressiveness or type safety. Existing frameworks for type-level computation either require totality or implicitly assume it. For example, type families in Haskell provide a powerful, modular means of defining type-level computation. However, their current design implicitly assumes that type families are total, introducing nonsensical types and significantly complicating the metatheory of type families and their extensions. We propose an alternative design, using qualified types to pair type-level computations with predicates that capture their domains. Our approach naturally captures the intuitive partiality of type families, simplifying their metatheory. As …

A Physics-Based Approach To Modeling Wildland Fire Spread Through Porous Fuel Beds, Tingting Tang

Theses and Dissertations--Mechanical and Aerospace Engineering

Wildfires are becoming increasingly erratic nowadays at least in part because of climate change. CFD (computational fluid dynamics)-based models with the potential of simulating extreme behaviors are gaining increasing attention as a means to predict such behavior in order to aid firefighting efforts. This dissertation describes a wildfire model based on the current understanding of wildfire physics. The model includes physics of turbulence, inhomogeneous porous fuel beds, heat release, ignition, and firebrands. A discrete dynamical system for flow in porous media is derived and incorporated into the subgrid-scale model for synthetic-velocity large-eddy simulation (LES), and a general porosity-permeability model is …

Long And Short-Range Air Navigation On Spherical Earth, Nihad E. Daidzic

International Journal of Aviation, Aeronautics, and Aerospace

Global range air navigation implies non-stop flight between any two airports on Earth. Such effort would require airplanes with the operational air range of at least 12,500 NM which is about 40-60% longer than anything existing in commercial air transport today. Air transportation economy requires flying shortest distance, which in the case of spherical Earth are Orthodrome arcs. Rhumb-line navigation has little practical use in long-range flights, but has been presented for historical reasons and for comparison. Database of about 50 major international airports from every corner of the world has been designed and used in testing and route validation. …

Visualizing Morphogenesis With The Processing Programming Language, Avik Patel, Amar Bains, Richard Millet, Tamira Elul

Faculty Publications & Research of the TUC College of Osteopathic Medicine

We used Processing, a visual artists’ programming language developed at MIT Media Lab, to simulate cellular mechanisms of morphogenesis – the generation of form and shape in embryonic tissues. Based on observations of in vivo time-lapse image sequences, we created animations of neural cell motility responsible for elongating the spinal cord, and of optic axon branching dynamics that establish primary visual connectivity. These visual models underscore the significance of the computational decomposition of cellular dynamics underlying morphogenesis.

Automated Refactoring Of Legacy Java Software To Default Methods, Raffi Khatchadourian, Hidehiko Masuhara

Publications and Research

Java 8 default methods, which allow interfaces to contain (instance) method implementations, are useful for the skeletal implementation software design pattern. However, it is not easy to transform existing software to exploit default methods as it requires analyzing complex type hierarchies, resolving multiple implementation inheritance issues, reconciling differences between class and interface methods, and analyzing tie-breakers (dispatch precedence) with overriding class methods to preserve type-correctness and confirm semantics preservation. In this paper, we present an efficient, fully-automated, type constraint-based refactoring approach that assists developers in taking advantage of enhanced interfaces for their legacy Java software. The approach features an extensive …

Exploratory Analysis Of Discourses Between Students Engaged In A Debugging Task, Ma. Mercedes T. Rodrigo

Department of Information Systems & Computer Science Faculty Publications

This paper determined if and how high-performing and low-performing students differed in the language that they used as they collaborated on a debugging task. 180 students worked in pairs to debug 12 small programs with known errors. Students were segregated into high and low achievement levels based on the number of bugs they found. Chat transcripts from the pairs were analyzed using the Linguistic Inquiry and Word Count (LIWC) software. We found that high- and low-performing students only varied in terms of their use of words that implied discrepancy and sadness.

Designing An Intervention For Novice Programmers Based On Meaningful Gamification: An Expert Evaluation, Jenilyn L. Agapito, Ma. Mercedes T. Rodrigo

Department of Information Systems & Computer Science Faculty Publications

Gamification is defined as the addition of game-like elements and mechanics to non-game contexts to encourage certain desired behaviors. It is becoming a popular classroom intervention used in computer science instruction, including CS1, the first course computer science students take. It is being operationalized to enhance students' learning experience and achievement. However, existing studies have mostly implemented reward-based game elements which have resulted to contrasting behaviors among the students. Meaningful gamification, characterized as the use of game design elements to encourage users build internal motivation to behave in a certain way, is contended to be a more effective approach. The …

Stochastic Invariants For Probabilistic Termination, Krishnendu Chatterjee, Petr Novotný, Dorde Zikelic

Research Collection School Of Computing and Information Systems

Termination is one of the basic liveness properties, and we study the termination problem for probabilistic programs with real-valued variables. Previous works focused on the qualitative problem that asks whether an input program terminates with probability 1 (almost-sure termination). A powerful approach for this qualitative problem is the notion of ranking supermartingales with respect to a given set of invariants. The quantitative problem (probabilistic termination) asks for bounds on the termination probability, and this problem has not been addressed yet. A fundamental and conceptual drawback of the existing approaches to address probabilistic termination is that even though the supermartingales consider …

The R Journal (December 2016) 8(2): Complete Issue, The R Foundation

The R Journal

Editorial, Michael Lawrence

Contributed Research Articles

multipleNCC: Inverse Probability Weighting of Nested Case-Control Data, Nathalie C. Støer and Sven Ove Samuelsen

QPot: An R Package for Stochastic Differential Equation Quasi-Potential Analysis, Christopher M. Moore, Christopher R. Stieha, Ben C. Nolting, Maria K. Cameron, and Karen C. Abbott

Design of the TRONCO BioConductor Package for TRanslational ONCOlogy, Marco Antoniotti, Giulio Caravagna, Luca De Sano, Alex Graudenzi, Giancarlo Mauri, Bud Mishra, and Daniele Ramazzotti

diverse: An R Package to Analyze Diversity in Complex Systems, Miguel R. Guevara, Dominik Hartmann, and Marcelo Mendoza

Simulating Correlated Binary and Multinomial Responses under Marginal Model Specification: …

Changes In R, R Core Team

The R Journal

CHANGES IN R 3.3.2 patched

News From The Bioconductor Project, Bioconductor Core Team

The R Journal

The Bioconductor project provides tools for the analysis and comprehension of high throughput genomic data. Bioconductor 3.4 was released on 18 October, 2016. It is com patible with R 3.3 and consists of 1296 software packages, 309 experiment data packages, and 933 up-to-date annotation packages. The release announcement includes descriptions of 101 new packages, and updated NEWS files for many additional packages. Start using Bioconductor by installing the most recent version of R and evaluating the commands

Mctest: An R Package For Detection Of Collinearity Among Regressors, Muhammad Imdadullah, Muhammad Aslam, Saima Altaf

The R Journal

It is common for linear regression models to be plagued with the problem of multicollinearity when two or more regressors are highly correlated. This problem results in unstable estimates of regression coefficients and causes some serious problems in validation and interpretation of the model. Different diagnostic measures are used to detect multicollinearity among regressors. Many statistical software and R packages provide few diagnostic measures for the judgment of multicollinearity. Most widely used diagnostic measures in these software are: coefficient of determination (R2), variance inflation factor/tolerance limit (VIF/TOL), eigenvalues, condition number (CN) and condition index (CI) etc. In this manuscript, we …

Weighted Distance Based Discriminant Analysis: The R Package Wedibadis, Itziar Irigoien, Francesc Mestres, Concepcion Arenas

The R Journal

The WeDiBaDis package provides a user friendly environment to perform discriminant analysis (supervised classification). WeDiBaDis is an easy to use package addressed to the biological and medical communities, and in general, to researchers interested in applied studies. It can be suitable when the user is interested in the problem of constructing a discriminant rule on the basis of distances between a relatively small number of instances or units of known unbalanced-class membership measured on many (possibly thousands) features of any type. This is a current situation when analyzing genetic biomedical data. This discriminant rule can then be used both, as …

Computing Pareto Frontiers And Database Preferences With The Rpref Package, Patrick Roocks

The R Journal

The concept of Pareto frontiers is well-known in economics. Within the database community there exist many different solutions for the specification and calculation of Pareto frontiers, also called Skyline queries in the database context. Slight generalizations like the combination of the Pareto operator with the lexicographical order have been established under the term database preferences. In this paper we present the rPref package which allows to efficiently deal with these concepts within R. With its help, database preferences can be specified in a very similar way as in a state-of-the-art database management system. Our package provides algorithms for an …

Dcovts: Distance Covariance/Correlation For Time Series, Maria Pitsillou, Konstantinos Fokianos

The R Journal

The distance covariance function is a new measure of dependence between random vectors. We drop the assumption of iid data to introduce distance covariance for time series. The R package dCovTS provides functions that compute and plot distance covariance and correlation functions for both univariate and multivariate time series. Additionally it includes functions for testing serial independence based on distance covariance. This paper describes the theoretical background of distance covariance methodology in time series and discusses in detail the implementation of these methods with the R package dCovTS.

Subgroup Discovery With Evolutionary Fuzzy Systems In R: The Sdefsr Package, Ángel M. García, Francisco Charte, Pedro González, Cristóbal J. Carmona, María J. Del Jesus

The R Journal

Subgroup discovery is a data mining task halfway between descriptive and predictive data mining. Nowadays it is very relevant for researchers due to the fact that the knowledge extracted is simple and interesting. For this task, evolutionary fuzzy systems are well suited algorithms because they can find a good trade-off between multiple objectives in large search spaces. In fact, this paper presents the SDEFSR package, which contains all the evolutionary fuzzy systems for subgroup discovery presented throughout the literature. It is a package without dependencies on other software, providing functions with recommended default parameters. In addition, it brings a graphical …

Variants Of Simple Correspondence Analysis, Rosaria Lombardo, Eric J. Beh

The R Journal

This paper presents the R package CAvariants (Lombardo and Beh, 2017). The package performs six variants of correspondence analysis on a two-way contingency table. The main function that shares the same name as the package– CAvariants– allows the user to choose (via a series of input parameters) from six different correspondence analysis procedures. These include the classical approach to (symmetrical) correspondence analysis, singly ordered correspondence analysis, doubly ordered correspondence analysis, non symmetrical correspondence analysis, singly ordered non symmetrical correspondence analysis and doubly ordered non symmetrical correspondence analysis. The code provides the flexibility for constructing either a classical correspondence plot or …