R绘图——ggplot2

ggplot2基本要素

代码语言：javascript复制

ggplot(data = iris) 
  geom_point(mapping = aes(x = Sepal.Length,
                           y = Petal.Length))

ggplot2默认没有引号，第一行为全局设置，以下分别为分图层。全局设置后一定要由 ，每个分图层可以单独设置映射aes

ggplot2 点图

代码语言：javascript复制

ggplot(data = iris)   
  geom_point(mapping = aes(x = Sepal.Length,
                           y = Petal.Length), 
             color = "blue") #分图层设置点的颜色
ggplot(data = iris)   
  geom_point(mapping = aes(x = Sepal.Length, y = Petal.Length), 
             size = 5,     # 点的大小5mm
             alpha = 0.5,  # 透明度 50%
             shape = 8)  # 点的形状


#通过分组设置不同颜色，同时自定义颜色
ggplot(data = iris) 
  geom_point(mapping = aes(x = Sepal.Length,
                           y = Petal.Length,
                           color = Species)) 
  scale_color_manual(values = c("blue","grey","red"))  #通过分组设置不同颜色，同时自定义颜色
  



#区别 fill和color
ggplot(data = iris) 
  geom_point(mapping = aes(x = Sepal.Length,
                           y = Petal.Length,
                           color = Species),
             shape = 17) #17号为实心，只需要color
              
ggplot(data = iris) 
  geom_point(mapping = aes(x = Sepal.Length,
                           y = Petal.Length,
                           color = Species),
             shape = 2) #2号为空心，color会给边框上色
             
             
ggplot(data = iris) 
  geom_point(mapping = aes(x = Sepal.Length,
                           y = Petal.Length,
                           color = Species),
             shape = 24,
             fill = "black") #fill会给点图内部填充颜色，填充黑色。
         

         
#分面函数facet_wrap                           
ggplot(data = iris)   
  geom_point(mapping = aes(x = Sepal.Length, y = Petal.Length))   
  facet_wrap(~ Species) #单分面，只分一次
  
  
dat = iris
dat$Group = sample(letters[1:5],150,replace = T)
ggplot(data = dat)   
  geom_point(mapping = aes(x = Sepal.Length, y = Petal.Length))   
  facet_grid(Group ~ Species)  #横竖两个分面，需要有纵向分组信息，即重复的若干组数字
  

全局设置，局部设置（图层）

代码语言：javascript复制

ggplot(data = iris)   
  geom_smooth(mapping = aes(x = Sepal.Length, 
                          y = Petal.Length)) 
  geom_point(mapping = aes(x = Sepal.Length, 
                           y = Petal.Length))
#以上等同于
ggplot(data = iris,mapping = aes(x = Sepal.Length, y = Petal.Length)) 
  geom_smooth() 
  geom_point()

直方图

代码语言：javascript复制

ggplot(data = diamonds)   
  geom_bar(mapping = aes(x = cut))

ggplot(data = diamonds)   
  stat_count(mapping = aes(x = cut)) #只有一个参数x，直方图统计的是频数

点图

代码语言：javascript复制

ggplot(data = iris,mapping = aes(x = Species, 
                                 y = Sepal.Width,
                                 fill = Species))   
  geom_boxplot() 
  geom_point() #箱图 点图
  


ggplot(data = iris,mapping = aes(x = Species, 
                                 y = Sepal.Width,
                                 fill = Species))   
  geom_boxplot() 
  geom_jitter() #箱图 抖点图
 

散点图

代码语言：javascript复制

ggsactter(iris,x="Sepal.Length",y="Petal")
    my_comparison=list(c("a","b"),c("c","d"))

来自生信技能树笔记

知识图谱

0 人点赞