stats coding midterm

Question 1

Obtain documentation for a given
R command

Answer 1

help()

Question 2

View some examples on the use of a command

Answer 2

example()

Question 3

Enter data manually to a vector in
R

Answer 3

c(), scan()

Question 4

Make arithmetic progression vector

Answer 4

seq()

Question 5

Make vector of repeated values

Answer 5

rep()

Question 6

Load (often into a data.frame) built-in dataset

Answer 6

data()

Question 7

View dataset in a spreadsheet-type format

Answer 7

View()

Question 8

Display internal structure of an R object

Answer 8

str()

Question 9

Load into a data.frame an existing data file

Answer 9

read.csv(), read.table()

Question 10

Make available an R add-on package

Answer 10

library(), require()

Question 11

See dimensions (# of rows/cols) of data.frame

Answer 11

dim()

Question 12

Give length of a vector

Answer 12

length()

Question 13

Lists memory contents

Answer 13

ls()

Question 14

Removes an item from memory

Answer 14

rm()

Question 15

Lists names of variables in a data.frame

Answer 15

names()

Question 16

Command for producing a histogram

Answer 16

hist()

Question 17

Lattice command for producing a histogram

Answer 17

histogram()

Question 18

List all values of a variable with frequencies

Answer 18

table()

Question 19

Make a stem plot

Answer 19

stem()

Question 20

Cross-tabulation tables using formulas

Answer 20

xtabs()

Question 21

Make a mosaic plot

Answer 21

mosaicplot()

Question 22

Groups values of a variable into larger bins

Answer 22

cut()

Question 23

Identify “center” of distribution

Answer 23

mean(), median()