ggplot2绘图（R_03）

#1.基础包 
plot(iris[,1],iris[,3],col = iris[,5]) #iris为数据框，以iris第一列为横坐标，第三列为纵坐标，第五列有多少个不同的取值则有多少种颜色
text(6.5,4, labels = 'hello')#在(6.5,4)坐标处添加“hello”

dev.off() #关闭画板

#2.ggplot2 中坚力量，语法有个性
library(ggplot2)
ggplot(data = iris)+
  geom_point(mapping = aes(x = Sepal.Length,
                           y = Petal.Length,
                           color = Species))#以iris数据框作点图，x=和y=分别表示行名和列名,Sepal.Length为数据框中的列名

ggplot(data=iris)+
geom_point(mapping=aes(x=Sepal.Length,y=Sepal.Length),size=2,alpha=0.5,shape=21)

ggplot(data=iris)+
geom_point(mapping=aes(x=Sepal.Length,y=Sepal.Length,color=Species))

ggplot(data=iris)+
geom_point(mapping=aes(x=Sepal.Length,y=Sepal.Length),color="red")

ggplot(data=iris)+
geom_point(mapping=aes(x=Sepal.Length,y=Sepal.Length,color=Species))+
scale_color_manual(values=c("blue","red","yellow"))

ggplot(data=iris)+
geom_point(mapping=aes(x=Sepal.Length,y=Sepal.Length,color=Species))+
facet_wrap(~Species)

dat = iris
dat$Group = sample(letters[1:5],150,replace = T)#sample表示取样，从abcde中取150个样（可重复取样）
ggplot(data = dat) + 
  geom_point(mapping = aes(x = Sepal.Length, y = Petal.Length)) + 
  facet_grid(Group ~ Species)

ggplot(data = iris,mapping = aes(x = Sepal.Length, y = Petal.Length))+
  geom_smooth()+
  geom_violin(aes(fill=species))+#小提琴图有颜色填充
  geom_jitter(aes(shape=1))#点的形状

ggplot(data = diamonds) + 
  geom_bar(mapping = aes(x = cut))#自动统计x出现的次数作为纵坐标
ggplot(data = diamonds) + 
  stat_count(mapping = aes(x = cut))#两种代码所作的图相同

ggplot(data = diamonds) + 
  geom_bar(mapping = aes(x = cut, y = ..prop.., group = 1))#group=1表示cut中的所有组作为一个整体，百分比相加等于1

library(ggplot2)
p = ggplot(pdat,aes(gene,count))+
  geom_boxplot(aes(fill = group))+
  theme_bw()
p
p + facet_wrap(~gene,scales = "free")