Programming with R Part 2

Question 1

How do you simulate data with R?

Answer 1

rnorm

Question 2

Why is setting the seed important?

Answer 2

So that you have the same randomness every time (repeatability)

Question 3

Why is it important to sample?

Answer 3

In the event that you have a large dataset, you can just work on a sample to test your algorithms

Question 4

How do you set matrices?

Answer 4

matrix(c(vector), nrow, ncol)

Question 5

if you want to do algebra, what symbol do you need in order to signify that?

Answer 5

%

for example, %*% will allow you to multiply

Question 6

How do you run a function?

Answer 6

apply(m, dimcode, function, functionArgs)

Question 7

What is a list?

Answer 7

A vector that can contain elements of different modes/classes/data types

Question 8

What are factors

Answer 8

Factors represent nominal/categorical data

> x x
[1] yes yes no yes no
Levels: no yes

Question 9

What are data frames?

Answer 9

Stores tabular data

Basically a 2D list (a list of lists)