---
title: "ggplot2展览馆"
author: 学徒
date: "2018-11-11"
categories:
- 教程
---
1. Histogram
```{r knitr_init, echo=FALSE, cache=FALSE, include=FALSE}
library(knitr)
library(ggplot2)
library(dplyr)
## Global options
options(max.print="75")
opts_chunk$set(echo=TRUE,
cache=TRUE,
prompt=FALSE,
tidy=TRUE,
comment=NA,
message=FALSE,
warning=FALSE)
opts_knit$set(width=75)
```
A simple histogram is like this:
```{r}
# load the dataset
data(midwest)
hist(midwest$percbelowpoverty, main = "A simple histogram",xlab = "Percentage below poverty" )
ggplot(data = midwest,
mapping = aes(x = percbelowpoverty)) +
theme_bw() +
geom_histogram(aes(y = ..density.., fill = percbelowpoverty)) +
labs(x = "Poverty Percentage", y = "Counts", title = "this plot") +
geom_density(aes(y = ..density..),col = "red", fill = "red", alpha = 0.5)
```
```{r}
midwest2 <- midwest %>%
mutate(bluepoint = ifelse(perchsd > 70 & percbelowpoverty < 20, 1, 0))
ggplot(midwest2,
aes(x = percbelowpoverty,
y = perchsd)) +
geom_point(aes(col = as.factor(state)), size = 2) +
geom_smooth(col = "red", se = FALSE)
```
```{r}
class_agg <- data.frame(table(mpg$class))
colnames(class_agg) <- c("a", "b")
ggplot(class_agg, aes(x = a, y = b)) + geom_bar(stat = "identity", aes(fill = a )) +
scale_fill_brewer(type = "qual", palette = 4, direction = -1)
```
