# ch18: Print examples of chapter 18 of 'R for Dummies'. In rfordummies: Code Examples to Accompany the Book "R for Dummies"

 ch18 R Documentation

## Print examples of chapter 18 of 'R for Dummies'.

### Description

To print a listing of all examples of a chapter, use `ch18()`. To run all the examples of `ch18()`, use `example(ch18)`.

### Usage

```ch18()
```

### See Also

`toc`

Other Chapters: `ch01()`, `ch02()`, `ch03()`, `ch04()`, `ch05()`, `ch06()`, `ch07()`, `ch08()`, `ch09()`, `ch10()`, `ch11()`, `ch12()`, `ch13()`, `ch14()`, `ch15()`, `ch16()`, `ch17()`, `ch19()`, `ch20()`

### Examples

```if (interactive()) {
# Chapter 18 - Looking At ggplot2 Graphics

# Installing and Loading ggplot2

## Not run:
install.packages("ggplot2")

## End(Not run)
library("ggplot2")

# Looking At Layers

ggplot(faithful, aes(x=eruptions, y=waiting)) + geom_point() + stat_smooth()

# Using Geoms and Stats

## Defining what data to use

## Mapping data to plot aesthetics

ggplot(faithful, aes(x=eruptions, y=waiting)) + geom_point() + stat_smooth()

## Getting geoms

### Creating a bar chart

ggplot(quakes, aes(x=depth)) + geom_bar()
ggplot(quakes, aes(x=depth)) + geom_histogram(binwidth=50)

quakes.agg <- aggregate(mag ~ round(depth, -1), data=quakes, FUN=length)
names(quakes.agg) <- c("depth", "mag")

ggplot(quakes.agg, aes(x=depth, y=mag)) +
geom_bar(stat="identity")

### Making a scatterplot

ggplot(quakes, aes(x=long, y=lat)) + geom_point()

### Creating line charts

ggplot(longley, aes(x=Year, y=Unemployed)) + geom_line()

# Sussing Stats

## Binning data

ggplot(quakes, aes(x=depth)) + geom_bar()
ggplot(quakes, aes(x=depth)) + stat_bin(binwidth = 50)

## Smoothing data

ggplot(longley, aes(x=Year, y=Employed)) + geom_point()

ggplot(longley, aes(x=Year, y=Employed)) +
geom_point() + stat_smooth()

ggplot(longley, aes(x=Year, y=Employed)) +
geom_point() + stat_smooth(method="lm")

# Adding Facets, Scales, and Options

## Adding facets

ggplot(mtcars, aes(x=hp, y=mpg)) + geom_point()

ggplot(mtcars, aes(x=hp, y=mpg)) + geom_point() +
stat_smooth(method="lm") + facet_grid(~cyl)

ggplot(mtcars, aes(x=hp, y=mpg)) +
geom_point(aes(shape=factor(cyl), colour=factor(cyl)))

ggplot(mtcars, aes(x=hp, y=mpg)) +
geom_point(aes(shape=factor(cyl), colour=factor(cyl))) +
scale_shape_discrete(name="Cylinders") +
scale_colour_discrete(name="Cylinders")

## Changing options

ggplot(mtcars, aes(x=hp, y=mpg)) + geom_point(color="red") +
xlab("Performance (horse power") +
ylab("Fuel consumption (mpg)") +
ggtitle("Motor car comparison")

}
```

rfordummies documentation built on March 18, 2022, 6:04 p.m.