SUMMARY R> plot(log(marketvalue) ~ log(sales), data = Forbes2000,

+

pch = ".")

17

6

4

log(marketvalue)

2

0

−2

−4

−4

−2

0

2

4

log(sales)

Figure 1.2

Raw scatterplot of the logarithms of market value and sales.

# 1.9 Summary

Reading data into R is possible in many different ways, including direct con- nections to data base engines. Tabular data are handled by data.frames in R, and the usual data manipulation techniques such as sorting, ordering or sub- setting can be performed by simple R statements. An overview on data stored in a data.frame is given mainly by two functions: summary and str. Simple graphics such as histograms and scatterplots can be constructed by applying the appropriate R functions (hist and plot) and we shall give many more examples of these functions and those that produce more interesting graphics in later chapters.