Computational Statistics

COMPLEX DATA TYPES A-203

Compound

Data Types

(cont.)

Lists analogous to vectors, with elements of possibly different types.

list() generates a list.

Syntax: list(hcomponentsi)

[[ ]] access to components of a list by index.

hlist$componenti

access by names.

Example: l <- list(name = "xyz", age = 22, fak = "math")

> l[[2]]

22

>l$age

22

Data Frames data frames analogous to arrays resp. lists, with column-wise uni-

form type and uniform column length.

data.frame()

analogous to list(), but restrictions have to be satisfied.

attach() attaches a database to the current search list. For access

to components the component name will be sufficient.

detach()

A-204 R AS A PROGRAMMING ...