R语言绘制拟合散点图时如何标注坐标轴上红色点对应的数值

实现方法 #

你可以直接使用R基础绘图系统的text()函数为该红色标记点添加数值标注，只需要在你绘制红色点的代码后追加标注代码即可，调整pos参数可以控制标注相对于点的位置（1为下方、2为左侧、3为上方、4为右侧），避免标注和坐标轴、红点重叠。

完整可运行代码 #

library(dplyr)
library(lubridate)
library(tidyverse)

df1 <- structure(
  list(date1 = c("2021-06-28","2021-06-28","2021-06-28","2021-06-28","2021-06-28",
                 "2021-06-28","2021-06-28","2021-06-28"),
       date2 = c("2021-04-02","2021-04-03","2021-04-08","2021-04-09","2021-04-10","2021-07-01","2021-07-02","2021-07-03"),
       Week= c("Friday","Saturday","Thursday","Friday","Saturday","Thursday","Friday","Monday"),
       DR01 = c(14,11,14,13,13,14,13,16), DR02= c(14,12,16,17,13,12,17,14),DR03= c(19,15,14,13,13,12,11,15),
       DR04 = c(15,14,13,13,16,12,11,19),DR05 = c(15,14,15,13,16,12,11,19),
       DR06 = c(21,14,13,13,15,16,17,18),DR07 = c(12,15,14,14,19,14,17,18)),
  class = "data.frame", row.names = c(NA, -8L))

#Generate graph

dmda<-"2021-07-01"

datas<-df1 %>%
  filter(date2 == ymd(dmda)) %>%
  summarize(across(starts_with("DR"), sum)) %>%
  pivot_longer(everything(), names_pattern = "DR(.+)", values_to = "val") %>%
  mutate(name = as.numeric(name))
colnames(datas)<-c("Days","Numbers")

plot(Numbers ~ Days, xlim=c(0,8), ylim=c(0,20), data = datas,xaxs='i')
model <- nls(Numbers ~ b1*Days^2+b2,start = list(b1 = 47,b2 = 0), data = datas)
new.data <- data.frame(Days = with(datas, seq(min(Days),max(Days),len = 45)))
new.data <- rbind(0, new.data)
lines(new.data$Days, predict(model, newdata=new.data))
points(0, coef(model)[2], col="red", pch=19, cex=1.2, xpd=TRUE)
# 新增标注代码：在红点右侧显示数值，保留2位小数
text(x = 0, y = coef(model)[2], labels = round(coef(model)[2],2), pos = 4, col = "red", cex = 0.9)

如果需要调整标注的样式，可以修改cex（字号）、font（字体粗细）等参数即可。

内容的提问来源于stack exchange，提问作者user16774617