Flashcards in Book - Chapter 3 basic analytics in r Deck (69)

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1

## What is the function to import data

### Read.csv

2

## What does the head function do

### Examines the imported dataset

3

## What does the summary function do

### Provide some descriptive statistics, such as mean and medium, for each data column

4

## When referring to a column in a dataset what symbol should you use

### The $

5

## How would you plot linear regression

### Lm

6

## What does our software use

### Commandline interface

7

## How do you set a working directory

### Set WD

8

## What are the categorical/qualitative attribute types

### Nominal and ordinal

9

## What are the numeric/quantitative attribute types

### Interval and ratio

10

## What are nominal data types

###
ZIP Codes

nationality

street names

gender

employee ID number

true or false

11

## What is an ordinal data type

###
Ordered names for example

quality of diamonds

academic grades

magnitude of earthquakes

12

## What is interval data types

### Numeric with no true zero for example Celsius or Fahrenheit

13

## What is ratio data type

### Numeric with a true zero for example age or temperature in Kelvin

14

## What is a vector

### Set of values of the same data type.

15

## What can you use to create vectors

### The combined function

16

## What dimension is a vector

### They are dimensionless

17

## What is a 2dimensional array

### Matrix

18

## What is an array

### N dimensional set of homogenous data type values

19

## What does the function nrow and nCol do

### Define the number of rows and columns

20

## What is a DataFrame

### Like a spreadsheet and list but all columns are the same length

21

## Can data frames stored different data types

### Yes

22

## What is the list

### A list is a collection of vectors and to be different lengths

23

## What is a factor

###
A set of categorical variables.

Fix set of values and use integer code to represent different values

24

## What does variance mean

### The distance from means squared

25

## What does standard deviation mean

### The square root of variance

26

## What does ranged mean

### Minimum to maximum

27

## What is interquartile range

### 25% to 75% of the size order data

28

## Why do we visualise

### To get a sense of the data

29

## What should we visualise

### Mean versus median. Standard deviation. Quantiles. Correlations between variables

30