Preface to First Edition - lib

INSTALLING R 3One can change the appearance of the prompt by> options(prompt = "R> ")and we will use the prompt R> for the display of the code examples throughoutthis book. A + sign at the very beginning of a line indicates a continuingcommand after a newline.Essentially, the R system evaluates commands typed on the R prompt andreturns the results of the computations. The end of a command is indicatedby the return key. Virtually all introductory texts on R start with an exampleusing R as a pocket calculator, and so do we:R> x print(x)[1] 71.2.2 PackagesThe base distribution already comes with some high-priority add-on packages,namelymgcv KernSmooth MASS baseboot class cluster codetoolsdatasets foreign grDevices graphicsgrid lattice methods nlmennet rcompgen rpart spatialsplines stats stats4 survivaltcltk tools utilsSome of the packages listed here implement standard statistical functionality,for example linear models, classical tests, a huge collection of high-level plottingfunctions or tools for survival analysis; many of these will be describedand used in later chapters. Others provide basic infrastructure, for examplefor graphic systems, code analysis tools, graphical user-interfaces or other utilities.Packages not included in the base distribution can be installed directlyfrom the R prompt. At the time of writing this chapter, 1756 user-contributedpackages covering almost all fields of statistical methodology were available.Certain so-called ‘task views’ for special topics, such as statistics in the socialsciences, environmetrics, robust statistics etc., describe important and helpfulpackages and are available from© 2010 by Taylor and Francis Group, LLC