BiplotGUI: Interactive Biplots in R

Biplots simultaneously provide information on both the samples and the variables ofa data matrix in two- or three-dimensional representations. The BiplotGUI package provides a graphical user interface for the construction of, interaction with, and manipulation of biplots in R. The samples are represented as points, with coordinates determined either by the choice of biplot, principal coordinate analysis or multidimensional scaling. Various transformations and dissimilarity metrics are available. Information on the original variables is incorporated by linear or non-linear calibrated axes. Goodness-of-t measures are provided. Additional descriptors can be superimposed, including convex hulls, alpha-bags, point densities and classication regions. Amongst the interactive features are dynamic variable value prediction, zooming and point and axis drag-and-drop. Output can easily be exported to the R workspace for further manipulation. Three-dimensional biplots are incorporated via the rgl package. The user requires almost no knowledge of R syntax

n Statistiese analise van die eienskappe en veranderlikheid van bolugtoestande oor die somerreenvalgebied van Suid-Afrika : met spesiale verwysing na haelvoorkoms

Proefskrif (M. Sc.) -- Universiteit van Stellenbosch, 1990.Full text to be digitised and attached to bibliographic record

n Statistiese analise van die eienskappe en veranderlikheid van bolugtoestande oor die somerreenvalgebied van Suid-Afrika : met spesiale verwysing na haelvoorkoms

Proefskrif (M. Sc.) -- Universiteit van Stellenbosch, 1990.Full text to be digitised and attached to bibliographic record

The impact of industry classification on the valuation accuracy of multiples in the South African capital market

The original publication is available at http://www.cluteinstitute.com/Publication of this article was funded by the Stellenbosch University Open Access Fund.Although multiples are used extensively in practice, empirical guidance in emerging markets is limited in this regard. In terms of valuation accuracy, the impact of peer group selection by way of industry classification in emerging markets has not yet been substantiated by research. This paper investigates the valuation performance of multiples over various industry classifications when valuing the equity of South African companies listed on the Johannesburg Stock Exchange for the period 2001 to 2010. The empirical results revealed that peer group selection based on a narrower industry classification could, on average, increase valuation accuracy by as much as 19.60%.Stellenbosch University Open Access FundPublishers' Versio

Flexible graphical assessment of experimental designs in R : the vdg package

CITATION: Schoonees, P., Le Roux, N. & Coetzer, R. 2016. Flexible graphical assessment of experimental designs in R : the vdg package. Journal of Statistical Software, 74(3):1-22, doi:10.18637/jss.v074.i03.The original publication is available at https://www.jstatsoft.orgThe R package vdg provides a flexible interface for producing various graphical summaries of the prediction variance associated with specific linear model specifications and experimental designs. These methods include variance dispersion graphs, fraction of design space plots and quantile plots which can assist in choosing between a catalogue of candidate experimental designs. Instead of restrictive optimization methods used in traditional software to explore design regions, vdg utilizes sampling methods to introduce more flexibility. The package takes advantage of R's modern graphical abilities via ggplot2 (Wickham 2009), adds facilities for using a variety of distance methods, allows for more flexible model specifications and incorporates quantile regressions to help with model comparison.https://www.jstatsoft.org/article/view/v074i03Publisher's versio

Temporal changes in the neonatal recognition cue of Dohne Merino Lambs (Ovis aries)

Please cite as follows:Viviers, M. Z. et al. 2014. Temporal Changes in the Neonatal Recognition Cue of Dohne Merino Lambs (Ovis aries). Chemical Senses, 39(3):249-262, doi: 10.1093/chemse/bjt075.The original publication is available at http://chemse.oxfordjournals.org/The strong bond that is formed between ewe and lamb after parturition is important for lamb survival. Evidence exists that the ewe mainly employs olfactory recognition cues to distinguish her lamb from other lambs in the flock. We have found that volatile organic compounds in the wool of Merino lambs that presumably constitute the neonatal recognition cue in sheep undergo temporal changes, at least during the first 100 days of their lives. To compensate for changes in the composition of the recognition cue, ewes are compelled to sample the changing effluvia of lambs to refresh their memories of their lambs’ odor in order to preserve the exclusive olfactory attachment to their lambs. These changes could be the reason for the well-known regular sniffing of ewes at their lambs. Parallel changes in the effluvia of twin lambs ensure the retention of the previously observed intra-twin similarity of the recognition cues of twin lambs. The coherent manner in which these changes take place probably contributes to the cohesion in a flock of sheep.Post-prin

Rapport d'étude : « Aizier (Eure) Chapelle Saint-Thomas. Fouille programmée d'une léproserie médiévale, rapport 2006 »

(Rapport d'étude), « Aizier (Eure) Chapelle Saint-Thomas. Fouille programmée d'une léproserie médiévale, rapport 2006 », Document final de synthèse, SRA Haute-Normandie, Rouen, 2 vol., 130 p. + pl

Understanding biplots

Biplots are a graphical method for simultaneously displaying two kinds of information; typically, the variables and sample units described by a multivariate data matrix or the items labelling the rows and columns of a two-way table. This book aims to popularize what is now seen to be a useful and reliable method for the visualization of multidimensional data associated with, for example, principal component analysis, canonical variate analysis, multidimensional scaling, multiplicative interaction and various types of correspondence analysis. Understanding Biplots: Introduces t

Neonatal recognition in sheep

The original publication is available at http://link.springer.com/chapter/10.1007%2F978-1-4614-5927-9_5 but only in print formatThe strong bond formed between ewe and lamb shortly after parturition is an important factor in lamb survival. Evidence exists that the ewe can distinguish her lamb by its unique smell, but the constituents of such a putative pheromone have not yet been identified. We have identified 133 volatile organic compounds in the cranial wool of Dohne Merino lambs that are presumably constituents of the neonatal recognition cue of this sheep race. Quantitative analysis and comparison of the odour profiles of the twins of 16 ewes of a flock of 165 twin-bearing ewes (9 .69% sample group) revealed that the wool volatiles of twins are qualitatively as well as quantitatively practically identical, but differ from those of other twins or non-twin lambs in the flock. The 88 constituents present in at least 20% of the analysed wool samples were considered as variables for multivariate analysis. A ?-value <0.0001 was calculated, indicating that the pairing of twins according to the qualitative and quantitative composition of the wool is statistically highly significant. Bioassays carried out during the lambing seasons of 2009 and 2010 confirmed the previously established role of the odour of lambs in ewe-lamb recognition. However, ewes rejected alien lambs dressed in jackets that were sprayed with mixtures formulated with synthetic analogues of the identified wool volatiles according to the qualitative and quantitative compositions of the experimental ewes' own lambs. This is probably due to the volatiles not being released into the atmosphere in quantitative ratios emulating the odour of the lambs accurately enough to satisfy the experimental ewes.Publishers' Versio