1 Chapter 1

Data is contained in gapminder package

1.1 Filter Verb

1.2 Arrange Verb

1.3 Mutate

replace existing variable

add new variables

1.4 combining verbs

2 Chapter 2 Visualizing with ggplot

## Log scales

## Additional aesthetics

3 Chaper 3 Summarise Verb

3.1 Group_by verb

3.2 Visualizing summerized data

make Y axis starts from 0

4 Chapter 4 Line Plots and Others

## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

## `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.