Preface to First Edition - lib

20 AN INTRODUCTION TO RR> plot(log(marketvalue) ~ log(sales), data = Forbes2000,+ pch = ".")log(marketvalue)−4 −2 0 2 4 6−4 −2 0 2 4log(sales)Figure 1.2Raw scatterplot of the logarithms of market value and sales.1.8 Organising an AnalysisAlthough it is possible to perform an analysis typing all commands directlyon the R prompt it is much more comfortable to maintain a separate text filecollecting all steps necessary to perform a certain data analysis task. Such anR transcript file, for example called analysis.R created with your favouritetext editor, can be sourced into R using the source commandR> source("analysis.R", echo = TRUE)When all steps of a data analysis, i.e., data preprocessing, transformations,simple summary statistics and plots, model building and inference as wellas reporting, are collected in such an R transcript file, the analysis can be© 2010 by Taylor and Francis Group, LLC