R语言可视化学习笔记之ggrepel包

taoyan：伪码农，R语言爱好者，爱开源。

个人博客: https://ytlogos.github.io/

library(ggplot2)

#使用数据集mtcars演示

ggplot(mtcars)+ geom_point(aes(wt, mpg), color="red")+geom_text(aes(wt, mpg, label=rownames(mtcars)))+theme_classic(base_size = 16)

可以看到可视化效果不是很好。接下来看看包ggrepel的效果。

geom_text_repel()是基于geom_text()

library(ggrepel)

set.seed(42)

ggplot(mtcars)+ geom_point(aes(wt, mpg), color="red")+

geom_text_repel(aes(wt, mpg, label=rownames(mtcars)))+

theme_classic(base_size = 16)

geom_label_repel()

geom_label_repel()是基于geom_label(),它将标签置于一个小方框中

set.seed(42)

ggplot(mtcars)+ geom_point(aes(wt, mpg), color="grey", size=5)+

geom_label_repel(aes(wt, mpg, fill=factor(cyl),

label=rownames(mtcars)), fontface="bold", color="white",

box.padding=unit(0.35, "lines"), point.padding=unit(0.5, "lines"),

segment.colour = "grey50")+ theme_classic(base_size = 16)

参数

大部分geom_text()的参数都适用于geom_text_repel(),除了以下几个：

hjust
vjust
position
check_overlap

ggrepel包为geom_text_repel()与geom_label_repel()提供了特有的参数设置：

segment.color:连接点与标签的线段的颜色
segment.size:线段的粗细
segment.alpha:线段的透明度
box.padding:文本框周边填充
point.padding:点周围填充
arrow:grid:arrow提供的箭头
force:强制性将重叠文本散开
max.oter:最大迭代次数
nudge_x/y:标签开始位置在坐标轴的移动距离
direction:允许标签的方向，x、y or both

下面举个栗子来详细了解这些参数的图形效果

set.seed(42)

ggplot(mtcars)+ geom_point(aes(wt, mpg, color=factor(cyl)), size=3)+

geom_text_repel(aes(wt, mpg, color=factor(cyl),

label=rownames(mtcars), angle=ifelse(mtcars$cyl==4, 90, 0)),

size=4, family="Times", fontface="bold",

box.padding=unit(0.5, "lines"), point.padding=unit(1.6, "lines"),

segment.color = "#cccccc", segment.size = 0.5,

arrow = arrow(length=unit(0.01, "npc")),force = 1, max.iter = 3e3,

nudge_x = ifelse(mtcars$cyl==6, 2, 0), nudge_y = ifelse(mtcars$cyl==6, 9, 0))+

scale_color_discrete(name="cyl")+

scale_x_continuous(expand = c(0.5, 0))+

scale_y_continuous(expand = c(0.25, 0))+

theme_classic(base_size = 16)

也可以通过设置参数point.padding=NA不对点进行repel

set.seed(42)

mtcars$label <- rownames(mtcars)

ggplot(mtcars, aes(wt, mpg, label=label))+

geom_point(color="red")+ geom_text_repel(point.padding = NA)+

theme_classic(base_size = 16)

通过赋值某些label空字符“”来隐藏。

set.seed(42)

mtcars$label <- rownames(mtcars)

mtcars$label[1:15] <- ""

ggplot(mtcars, aes(wt, mpg))+ geom_point(aes(color=factor(cyl)), size=2)+

geom_text_repel(aes(color=factor(cyl), size=hp, label=label),

point.padding = unit(0.25, "lines"), box.padding = unit(0.25, "lines"),

nudge_y = 0.1)+ theme_classic(base_size = 16)

将标签控制在特定区域

通过设置参数xlim和ylim来限制label的位置

set.seed(42)

data <- mtcars

mu <- mean(data$wt)

left <- data[data$wt <mu, ]

right <- data[data$wt>=mu, ]

ggplot()+ geom_vline(xintercept = mu)+

geom_point(aes(wt, mpg), data=data)+

geom_text_repel(data=left, aes(wt, mpg, label=rownames(left),

color="Left half"), xlim=c(NA, mu))+

geom_text_repel(data=right, aes(wt, mpg, label=rownames(right),

color="Rigth half"), xlim=c(mu, NA))+ theme_classic(base_size = 16)

通过控制参数direction来决定label是左右移动还是上下移动，默认是both

set.seed(42)

#direction="x" 左右移动

ggplot(mtcars)+

geom_point(aes(wt, mpg), color="red")+

geom_text_repel(aes(wt, mpg, label=rownames(mtcars)), direction="x")+

theme_classic(base_size = 16)+xlim(1, 6)

#direction="x" 上下移动

ggplot(mtcars)+

geom_point(aes(wt, mpg), color="red")+

geom_text_repel(aes(wt, mpg, label=rownames(mtcars)), direction="y")+

theme_classic(base_size = 16)+xlim(1, 6)

线图

set.seed(42)

ggplot(Orange, aes(age, circumference, color=Tree))+

geom_line()+

coord_cartesian(xlim=c(min(Orange$age), max(Orange$age)+90))+

geom_text_repel(data=subset(Orange, age==max(age)),

aes(label=paste("Tree", Tree)),size=6, nudge_x = 45, segment.color = NA)+

theme_classic(base_size = 16)+

theme(legend.position = "none")+

labs(title="Orange Trees", x="Age(days)", y="Circumference(mm)")