R语言ggplot2画图3

程序员文章站 2022-07-14 20:56:33

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geom_label()和ggplot_Text()的使用详解

主要是用于在图中标注文本

??geom_label()可以查看其帮助文档
##Examples
p <- ggplot(mtcars, aes(wt, mpg, label = rownames(mtcars)))###建立一个新的画板，标记mtcars的行名
p + geom_text()##展示待标记的文本内容，待标记的文本坐标是(wt,mpg)  见图1


# Labels with background
p +  geom_label(aes(fill = factor(cyl)), colour = "white",family = "Times New Roman", fontface = "bold",check_overlab=TRUE)  ###带背景标注,背景填充白色，新罗马黑体字体，重叠去除，见图2

# Set aesthetics to fixed value
p + geom_point(color="green",aes(size = wt),pch=8) + ##点的颜色为绿色，点的大小按照wt进行分配
  geom_text(hjust = 0, nudge_x = 0.05,##标注的水平方向调整为0，x向右移0.05
            vjust = 0, nudge_y = 0.5,aes(colour = factor(cyl)),##标注的垂直方向调整为0，y向上移0.05
            angle=45,family = "Times New Roman",check_overlap = TRUE,fontface ="bold")+  ##标记的倾角为45°，标记的字体(family)选择新罗马字体(fontface)黑体，有重叠的标记去掉
  scale_colour_discrete(l = 40)  见图3
  
# Scale height of text, rather than sqrt(height)
p + geom_text(aes(size = wt)) +scale_radius(range = c(3,6))

####标注不同的符号及公式
p + geom_point()+geom_text(aes(label = paste(wt, "^(", cyl, ")", sep = ""),hjust = 0, nudge_x = 0.05,###其中的paste 函数的使用
                               vjust = 0, nudge_y = 0.5,colour = factor(cyl),size=wt,check_overlap = TRUE),parse = TRUE)+annotate("text", label = "plot mpg vs. wt", x = 2, y = 15, size = 8, colour = "red")###添加文本注释 ，标签为plot mpg vs. wt，x和y分别是添加的标签的中心位置 ，大小为8 ，颜色为红色  见图4

# Aligning labels and bars --------------------------------------------------
df <- data.frame(
  x = factor(c(1, 1, 2, 2)),
  y = c(1, 3, 2, 1),
  grp = c("a", "b", "a", "b")
)

# ggplot2 doesn't know you want to give the labels the same virtual width
# as the bars:
ggplot(data = df, aes(x, y, group = grp)) +
  geom_col(aes(fill = grp), position = "dodge") +
  geom_text(aes(label = y, y = y + 0.05), position = position_dodge(0.9),vjust=-1)##标签按照y 添加，添加的位置在dodge的0.9(中间或者1)，vjust调整垂直方向(1，向图形内部移，负值向图形外部移动)  见图5

###position_dodge表示按照grp因子分开作图，position_stack()表示按照因子堆积作图
ggplot(data = df, aes(x, y, group = grp)) +
  geom_col(aes(fill = grp)) +
  geom_text(aes(label = y), position = position_stack(vjust = 0.5))见图6

# Justification -------------------------------------------------------------
df <- data.frame(
  x = c(1, 1, 2, 2, 1.5),
  y = c(1, 2, 1, 2, 1.5),
  text = c("bottom-left", "bottom-right", "top-left", "top-right", "center")  ##标记一组标签
)

ggplot(df, aes(x, y)) +
  geom_text(aes(label = text), vjust = "inward", hjust = "inward",colour="blue")##调整标签在途中的位置，向内部调整  见图7

图1
R语言ggplot2画图3