Lesson 3

Question 1

Creating a basic sequence of numbers e.g. 1-15

Answer 1

x < - 1:15

Question 2

Sequence function

Answer 2

seq(x)

e.g. seq(from=x, to=y)

Question 3

Creating a sequence with numbers incremented by a certain value

Answer 3

seq(x, y, by=z)

Question 4

Creating a sequence of X numbers between Y and Z

Answer 4

seq(y, z, length=x)

Question 5

Generating a sequence of numbers the length of an already created vector

Answer 5

1:length(vectorX)

seq(along.with = vectorX)

Question 6

Replicate function

Answer 6

rep(x)

Question 7

Getting rid of all values greater or equal to X in vectorY (indexing)

Answer 7

vectorY < - vectorY [vectorY < X]

Question 8

Getting rid of certain values within a vector

Answer 8

vector < - vector [-c(x, y)]

Question 9

Creating a list

Answer 9

list(x)

Question 10

Getting the X element of the Y vector inside a list

Answer 10

list [[Y]] [X]

Question 11

Naming vectors inside a list

Answer 11

names(list) < - c(“vector1”, “vector2”…)

Question 12

Indexing a named vector

Answer 12

list $ vectorX [y]

Question 13

Creating a data frame

Answer 13

data.frame(vectorX, vectorY, vectorZ…)

Question 14

Printing elements inside a data frame

Answer 14

df [rowX, colY]