Using R and RStudio for Data Management, Statistical Analysis, and Graphics, 2nd Edition

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“K23166” — 2015/1/28 — 9:35 — page 31 — #57

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2.6. EXAMPLES 31

> tally(~ female + gender, margin=FALSE, data=newds)

gender

female Male Female

0 346 0

1 0 107

2.6.4 Sorting and subsetting datasets

It is often useful to sort datasets (2.3.10) by the order of a particular variable (or variables).

Here we sort by CESD and drinking.

> library(dplyr)

> newds = arrange(ds, cesd, i1)

> newds[1:5, c("cesd", "i1", "id")]

cesd i1 id

1 1 3 233

2 3 1 139

3 3 13 418

4 4 4 251

5 4 9 95

It is sometimes necessary to create data that is a subset (2.3.1) of other data. Here we make

a dataset that only includes female subjects. First, we create the subset and calculate a

summary ...