CODAPACK3D. A new version of Compositional Data Package

The statistical analysis of compositional data should be treated using logratios of parts, which are difficult to use correctly in standard statistical packages. For this reason a freeware package, named CoDaPack was created. This software implements most of the basic statistical methods suitable for compositional data. In this paper we describe the new version of the package that now is called CoDaPack3D. It is developed in Visual Basic for applications (associated with Excel©), Visual Basic and Open GL, and it is oriented towards users with a minimum knowledge of computers with the aim at being simple and easy to use. This new version includes new graphical output in 2D and 3D. These outputs could be zoomed and, in 3D, rotated. Also a customization menu is included and outputs could be saved in jpeg format. Also this new version includes an interactive help and all dialog windows have been improved in order to facilitate its use. To use CoDaPack one has to access Excel© and introduce the data in a standard spreadsheet. These should be organized as a matrix where Excel© rows correspond to the observations and columns to the parts. The user executes macros that return numerical or graphical results. There are two kinds of numerical results: new variables and descriptive statistics, and both appear on the same sheet. Graphical output appears in independent windows. In the present version there are 8 menus, with a total of 38 submenus which, after some dialogue, directly call the corresponding macro. The dialogues ask the user to input variables and further parameters needed, as well as where to put these results. The web site http://ima.udg.es/CoDaPack contains this freeware package and only Microsoft Excel© under Microsoft Windows© is required to run the software. Kew words: Compositional data Analysis, Software

Hardy-Weinberg Equilibrium and the Ternary Plot

The Hardy-Weinberg law, formulated about 100 years ago, states that under certain assumptions, the three genotypes AA, AB and BB at a bi-allelic locus are expected to occur in the proportions p2, 2pq, and q2 respectively, where p is the allele frequency of A, and q = 1-p. There are many statistical tests being used to check whether empirical marker data obeys the Hardy-Weinberg principle. Among these are the classical xi-square test (with or without continuity correction), the likelihood ratio test, Fisher's Exact test, and exact tests in combination with Monte Carlo and Markov Chain algorithms. Tests for Hardy-Weinberg equilibrium (HWE) are numerical in nature, requiring the computation of a test statistic and a p-value. There is however, ample space for the use of graphics in HWE tests, in particular for the ternary plot. Nowadays, many genetical studies are using genetical markers known as Single Nucleotide Polymorphisms (SNPs). SNP data comes in the form of counts, but from the counts one typically computes genotype frequencies and allele frequencies. These frequencies satisfy the unit-sum constraint, and their analysis therefore falls within the realm of compositional data analysis (Aitchison, 1986). SNPs are usually bi-allelic, which implies that the genotype frequencies can be adequately represented in a ternary plot. Compositions that are in exact HWE describe a parabola in the ternary plot. Compositions for which HWE cannot be rejected in a statistical test are typically “close" to the parabola, whereas compositions that differ significantly from HWE are “far". By rewriting the statistics used to test for HWE in terms of heterozygote frequencies, acceptance regions for HWE can be obtained that can be depicted in the ternary plot. This way, compositions can be tested for HWE purely on the basis of their position in the ternary plot (Graffelman & Morales, 2008). This leads to nice graphical representations where large numbers of SNPs can be tested for HWE in a single graph. Several examples of graphical tests for HWE (implemented in R software), will be shown, using SNP data from different human populations

Mixing compositions and other scales

Theory of compositional data analysis is often focused on the composition only. However in practical applications we often treat a composition together with covariables with some other scale. This contribution systematically gathers and develop statistical tools for this situation. For instance, for the graphical display of the dependence of a composition with a categorical variable, a colored set of ternary diagrams might be a good idea for a first look at the data, but it will fast hide important aspects if the composition has many parts, or it takes extreme values. On the other hand colored scatterplots of ilr components could not be very instructive for the analyst, if the conventional, black-box ilr is used. Thinking on terms of the Euclidean structure of the simplex, we suggest to set up appropriate projections, which on one side show the compositional geometry and on the other side are still comprehensible by a non-expert analyst, readable for all locations and scales of the data. This is e.g. done by defining special balance displays with carefully- selected axes. Following this idea, we need to systematically ask how to display, explore, describe, and test the relation to complementary or explanatory data of categorical, real, ratio or again compositional scales. This contribution shows that it is sufficient to use some basic concepts and very few advanced tools from multivariate statistics (principal covariances, multivariate linear models, trellis or parallel plots, etc.) to build appropriate procedures for all these combinations of scales. This has some fundamental implications in their software implementation, and how might they be taught to analysts not already experts in multivariate analysis

wxGRASS: una interfaz gráfica de usuario para la integración de diversos programas libres para SIG

This paper presents a Graphical User Interface, developed with python and the graphic library wxpython, to GRASS GIS. This GUI allows to access several modules with a graphic interface written in Spanish. Its main purpouse is to be a teaching tool, that is the reason way it only allows to access several basic put crucial moludes. It also allows user to organize the elements presented to stress the aspects to be resalted in a particular working sesion with the program

Vision-based localization of an underwater robot in a structured environment

This paper presents a vision-based localization approach for an underwater robot in a structured environment. The system is based on a coded pattern placed on the bottom of a water tank and an onboard down looking camera. Main features are, absolute and map-based localization, landmark detection and tracking, and real-time computation (12.5 Hz). The proposed system provides three-dimensional position and orientation of the vehicle along with its velocity. Accuracy of the drift-free estimates is very high, allowing them to be used as feedback measures of a velocity-based low-level controller. The paper details the localization algorithm, by showing some graphical results, and the accuracy of the system

Neptune: a hil simulator for multiple UUVs

This paper overviews the field of graphical simulators used for AUV development, presents the taxonomy of these applications and proposes a classification. It also presents Neptune, a multivehicle, real-time, graphical simulator based on OpenGL that allows hardware in the loop simulations

Jmodels: Java models of earth system regulation

The JModel suite consists of a number of models of aspects of the Earth System. They can all be run from the JModels website. They are written in the Java language for maximum portability, and are capable of running on most computing platforms including Windows, MacOS and Unix/Linux. The models are controlled via graphical user interfaces (GUI), so no knowledge of computer programming is required to run them. The models currently available from the JModels website are: Ocean phosphorus cycle Ocean nitrogen and phosphorus cycles Ocean silicon and phosphorus cycles Ocean and atmosphere carbon cycle Energy radiation balance model (under development) The main purpose of the models is to investigate how material and energy cycles of the Earth system are regulated and controlled by different feedbacks. While the central focus is on these feedbacks and Earth System stabilisation, the models can also be used in other ways. These resources have been developed by: National Oceanography Centre, Southampton project led by Toby Tyrrell and Andrew Yool, focus on how the Earth system works.

Introduction to Matlab - a self-study tutorial

Matlab is a high level language that is very easy to use and very powerful. It comes with a wealth of libraries and toolboxes, that you can use directly, so that you don't need to program low level functions. It enables you to display results very easily on graphs and images. To get started with it, you need to understand how to manipulate and represent data, and how to find information about the available functions. During this self-study tutorial, you will learn: 1- How to start Matlab. 2- How you can find out all the information you need. 3- How to create simple vectors and matrices. 4- What functions are available and how to find them. 5- How to plot graphs of functions. 6- How to write a script. After this (should take about an hour), you will know most of what you need to know about Matlab and should definitely know how to go on learning about it on your own…

Matlab self study tutorial - Graphing

These resources are designed to support students in gaining more confidence with using Matlab. The PDFs provide guidance and information; Objectives: Introduce basic syntax and data preparation for graphing with Matlab by providing some data, examples of code and some background documents. Outcomes: -how to write an m file script -the importance of syntax -how to load files -how to produce simple graphs -where to get help and further examples There are also some data files to provide example data for students to work with in producing Matlab resources.

INFO2009 - Team 'DROP TABLE groups;

Edshare for INFO2009 coursework 2 - Team 'DROP TABLE groups;

Mac Printing Password update (workaround)

Quick video for iSolutions to sanity check workaround as all staff will be asked to change network passwords which could have a major affecting on staff authenticating to network printers from a Mac. If good can be used by Serviceline. Do not Contact Adam Procter about this

Password cracking for fun and profit

Abstract Passwords are the most common form of authentication, and most of us will have to log in to several accounts every day which require passwords. Unfortunately, passwords often do not do a good job of proving who we are, and come with a host of usability problems. Probably the only reason that passwords still exist is that there often isn't a better alternative, so we are likely to be stuck with them for the foreseeable future. Password cracking has been a problem for years, and becomes more problematic as computer become more powerful and attackers get a better idea of the sort of passwords people use. This presentation will look at two free password cracking tools: Hashcat and John the Ripper, and how even a non-expert on a laptop (i.e. me) can use them effectively. An introduction to some of the research surrounding the economics and usability of passwords will also be discussed. Note that the speaker is not an expert in this area, so it will be a fairly informal since I'm sure you're all tired after a long term.

Análisis del manejo de la información por parte de la Revista Semana respecto al Polo Democrático Alternativo y al Movimiento Progresistas: periodo: 2008-2012

A través del tiempo se ha logrado ver cómo los medios de comunicación penetran cada vez más la forma de pensar, e incluso de actuar, de la gente. Políticamente se han convertido en herramientas de disuasión, alienación o simplemente distracción. En Colombia, revista Semana se ha caracterizado por tener un criterio y una práctica seria del periodismo, en este sentido, vale la pena analizar cómo se ha desempeñado este medio ante el tratamiento de la información frente a los movimientos de izquierda con participación en el Estado, específicamente el Polo Democrático y el movimiento Progresistas, con el fin analizar la calidad y objetividad de la información basados en puntos específicos como el discurso mediático, el análisis gráfico y la percepción de los principales líderes políticos de estos movimientos y periodistas.

An exploratory assessment of the potential impact of the free trade area of the americas on the andean community

A través de una simulación llevada a cabo con GTAP, este documento presenta una evaluación preliminar del impacto potencial que el Área de Libre Comercio de las Américas tendría sobre la Comunidad Andina de Naciones. Mantenido por la Universidad de Purdue, el GTAP es un modelo multiregional de equilibrio general, ampliamente usado para el análisis de temas de economía internacional. El experimento llevado a cabo tiene lugar en un ambiente de competencia perfecta y rendimientos constantes a escala y consiste en la completa eliminación de aranceles a las importaciones de bienes entre los países del Hemisferio Occidental. Los resultados muestran la presencia de modestas pero positivas ganancias netas de bienestar para la Comunidad Andina, generadas fundamentalmente por mejoras en la asignación de recursos. Movimientos desfavorables en los términos de intercambio y el efecto de la desviación de comercio con respecto a terceros países, reducen considerablemente las ganancias potenciales de bienestar. De la misma forma, la existencia de distorsiones económicas al interior de la Comunidad Andina tiene un efecto negativo sobre el bienestar. El patrón de comercio aumenta su grado de concentración en el comercio bilateral con los Estados Unidos y la remuneración real a los factores productivos presenta mejoras con la implementación de la zona de libre comercio.

Geo-habilitación de Gestores de Contenidos: CMSMap

El mundo del software está cambiando. El desarrollo de Internet y las conexiones de datos hacen que las personas estén conectadas prácticamente en cualquier lugar. La madurez de determinadas tecnologías y el cambio del perfil de los usuarios de consumidor a generador de contenidos son algunos de los pilares de este cambio. Los Content Management Systems (CMS) son plataformas que proporcionan la base para poder generar webs colaborativas de forma sencilla y sin necesidad de tener excesivos conocimientos previos y son responsables de buena parte de este desarrollo. Una de las posibilidades que todavía no se han explotado suficientemente en estos sistemas es la georreferenciación de contenidos. De esta forma, aparece una nueva categoría de enlaces semánticos en base a las relaciones espaciales. En el actual estado de la técnica, se puede aprovechar la potencia de las bases de datos espaciales para manejar contenidos georreferenciados y sus relaciones espaciales, pero prácticamente ningún CMS lo aprovecha. Este proyecto se centra en desarrollar un módulo para el CMS Drupal que proporcione un soporte verdaderamente espacial y una interfaz gráfica en forma de mapa, mediante las que se puedan georreferenciar los contenidos. El módulo es independiente del proveedor de cartografía, ya que se utiliza la librería Open Source de abstracción de mapas IDELab Mapstraction Interactive. De esta forma se aúna la independencia tecnológica con la gestión verdaderamente espacial de los contenidos