A compositional data analysis package for R providing multiple approaches

”compositions” is a new R-package for the analysis of compositional and positive data. It contains four classes corresponding to the four different types of compositional and positive geometry (including the Aitchison geometry). It provides means for computation, plotting and high-level multivariate statistical analysis in all four geometries. These geometries are treated in an fully analogous way, based on the principle of working in coordinates, and the object-oriented programming paradigm of R. In this way, called functions automatically select the most appropriate type of analysis as a function of the geometry. The graphical capabilities include ternary diagrams and tetrahedrons, various compositional plots (boxplots, barplots, piecharts) and extensive graphical tools for principal components. Afterwards, ortion and proportion lines, straight lines and ellipses in all geometries can be added to plots. The package is accompanied by a hands-on-introduction, documentation for every function, demos of the graphical capabilities and plenty of usage examples. It allows direct and parallel computation in all four vector spaces and provides the beginner with a copy-and-paste style of data analysis, while letting advanced users keep the functionality and customizability they demand of R, as well as all necessary tools to add own analysis routines. A complete example is included in the appendix

New Features of CoDaPack. An Userfriendly Compositional Data Package

The statistical analysis of compositional data is commonly used in geological studies. As is well-known, compositions should be treated using logratios of parts, which are difficult to use correctly in standard statistical packages. In this paper we describe the new features of our freeware package, named CoDaPack, which implements most of the basic statistical methods suitable for compositional data. An example using real data is presented to illustrate the use of the package

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

News from compositions, the R package

The R-package “compositions”is a tool for advanced compositional analysis. Its basic functionality has seen some conceptual improvement, containing now some facilities to work with and represent ilr bases built from balances, and an elaborated subsys- tem for dealing with several kinds of irregular data: (rounded or structural) zeroes, incomplete observations and outliers. The general approach to these irregularities is based on subcompositions: for an irregular datum, one can distinguish a “regular” sub- composition (where all parts are actually observed and the datum behaves typically) and a “problematic” subcomposition (with those unobserved, zero or rounded parts, or else where the datum shows an erratic or atypical behaviour). Systematic classification schemes are proposed for both outliers and missing values (including zeros) focusing on the nature of irregularities in the datum subcomposition(s). To compute statistics with values missing at random and structural zeros, a projection approach is implemented: a given datum contributes to the estimation of the desired parameters only on the subcompositon where it was observed. For data sets with values below the detection limit, two different approaches are provided: the well-known imputation technique, and also the projection approach. To compute statistics in the presence of outliers, robust statistics are adapted to the characteristics of compositional data, based on the minimum covariance determinant approach. The outlier classification is based on four different models of outlier occur- rence and Monte-Carlo-based tests for their characterization. Furthermore the package provides special plots helping to understand the nature of outliers in the dataset. Keywords: coda-dendrogram, lost values, MAR, missing data, MCD estimator, robustness, rounded zeros

El Cos com a instrument musical: creativitat i activitat grupal col·laborativa com a proposta didàctica més enllà del context de l'aula

Sabem que l’educació no es circumscriu només en l’àmbit acadèmic ni dins el marc físic d’un centre docent, sinó que la societat i els productes que genera són elements importants a tenir en compte. En base a aquests supòsits, els nous corrents pedagògics de l’Escola Nova sorgits a començaments del segle XX ja recomanaven obrir les escoles a l’entorn immediat i aprofitar les seves possibilitats tant com a recurs educatiu com a contingut curricular en sí mateix. Aquesta premissa –plenament vigent a l’actualitat– es fa palesa especialment a l’àrea de música, no només per la gran quantitat d’informació –immediata i diversificada- i per les possibilitats didàctiques i educatives de caràcter multimèdia i interactiu de les Noves Tecnologies (NNTT), les Tecnologies de la Informació i la Comunicació (TIC) i les Tecnologies de l’Aprenentatge i la Comunicació (TAC) que configuren l’actual realitat virtual a la que ens veiem abocats, sinó per l’ampli ventall d’estils i gèneres que inclouen les programacions d’espectacles musicals al nostre abast. De la mateixa manera que l’audició de música en directe és del tot imprescindible en aquesta àrea artística i humanística per tal de desenvolupar les destreses que li són pròpies, també ho és la participació activa. En aquest sentit, constatem que la realització d’activitats educatives a nivell col·lectiu permet la interacció entre iguals i la descoberta, desenvolupament o aprofundiment d’actituds com la cooperació, la tolerància, el respecte mutu, la cohesió, etc., valors imprescindibles en una societat democràtica i plural com la nostra. I encara més, que l’activitat col·lectiva realitzada amb l’objectiu de produir un producte propi, afavoreix la satisfacció personal final que conduirà a la veritable integració dels continguts a assimilar. Per tant, la pràctica aplicada d’aquestes actituds i destreses socials es fa imprescindible en els estudis dels futurs docents. L'Espai Europeu de Educació Superior (EEES) ens aporta la incorporació d'un concepte provinent del món professional, les competències, que són un nou referent de rang superior que orienta globalment els estudis universitaris. Els objectius i continguts d'aquests tindran sentit en la mesura que contribueixin a desenvolupar algunes d'aquestes competències, ja que seran l'objecte principal d'avaluació de les titulacions. Pensem que a través d’activitats que es poden fer fora de l'aula com la que presentem en aquesta comunicació, s'ajuda a mobilitzar algunes d'aquestes competències que permetran configurar el perfil de graduat que tots desitgem

Adaptive integral assessment package for the A2UN@ project

This paper presents a first approach of Evaluation Engine Architecture (EEA) as proposal to support adaptive integral assessment, in the context of a virtual learning environment. The goal of our research is design an evaluation engine tool to assist in the whole assessment process within the A2UN@ project, linking that tool with the other key elements of a learning design (learning task, learning resources and learning support). The teachers would define the relation between knowledge, competencies, activities, resources and type of assessment. Providing this relation is possible obtain more accurate estimations of student's knowledge for adaptive evaluations and future recommendations. The process is supported by usage of educational standards and specifications and for an integral user modelling

Empowerment: model i instrument de mesura basat en les variables primàries o efectives PIEQ (Primary Items Empowerment Questionnaire)

In this thesis a review of the state of the art on empowerment is found. A proposal is put forward for a model of the effective variables of empowerment, a new theoretical model that provides a distinct classification of individual variables. The model consists of four metavariables called reciprocal, unidirectional, shared and reflexive. Finally, a measurement tool for measuring and representing these variables graphically is described, including its process of elaboration through a preliminary pilot study that served to refine and improve the questionnaire. Both the model and the instrument proposed aim to determine the state of the primary variables involved in determining the predisposition and potential of a working group towards empowerment. With the measurement tool both organisational, departmental, working group and/or individual data can be obtained. This instrument can help companies and organisations to discover the limitations existing within a working group and act in consequence.