R语言绘图小细节

改文字字体、大小、斜体

• 字体family
  • serif：Times New Roman
  • sans：Arial
  • mono：Couries New
  • KT： 楷体
  • ST：宋体
• 字体粗斜face
  • "plain"：不加粗
  • "italic"：斜体
  • "bold"：粗体
  • "bold.italic"：粗斜体

ggplot(mpg, aes(y = class)) +
  geom_bar(aes(fill = drv), 
           position = position_stack(reverse = TRUE)) +
  theme_classic()+
  theme( 
    legend.position = c(0.89,0.2),  ## 图例位置
    legend.direction = "horizontal",   ## 图例方向
    axis.text.y=element_text(size=15,   ## 字号大小
                             family = "mono", ## 字体  
                             face="bold.italic"),    ## 粗体，斜体
    axis.text.x=element_text(size=15))

加文字注释

使用annotate函数

xrng=range(mpg$displ)
yrng=range(mpg$cty)

caption_df=data.frame(lab=c("The first line annotation",
                            "The second line annotation",
                            "The third line annotation"))
caption <- paste(caption_df$lab, 
                 collapse = "\n") 

ggplot(mpg, aes(displ, cty)) + 
  geom_point() + 
  theme_classic()+
  annotate(geom = "text", 
           x = xrng[2]*0.92, 
           y = yrng[2]*0.95, 
           label = caption)

(对喔，这个地方怎么让文字靠左对齐呢？？还没有完善)

隐藏图例分组标题

使用guides(colour=guide_legend(title = NULL))

p1<-ggplot(mtcars, aes(wt, mpg)) + 
  geom_point(aes(colour = factor(cyl),
                 shape = factor(cyl)))+
  theme_bw()
                                                                        
p2<-ggplot(mtcars, aes(wt, mpg)) + 
  geom_point(aes(colour = factor(cyl),
                 shape = factor(cyl)))+
  theme_bw()+
  guides(colour=guide_legend(title = NULL),
         shape=guide_legend(title = NULL))
p1|p2                

左边是不隐藏图例标题的,右边是隐藏了图例标题(这个例子举的不太好，看不出来4，6，8是什么，如果能明确看出来是什么分组的话，就可以不用分组group的标题了)