如何在 ggplot 上的确切位置放置插图并设置 geom_segment 的颜色？

编程问答 2022-05-14

问题描述

我正在创建一个关于 loess 工作原理的插图。我的两个疑问在这个问题的末尾。一、设置：

library(tidyverse)
data(melanoma,package = "lattice")
mela <- as_tibble(melanoma)
tric = function(x) if_else(abs(x) < 1,(1 - abs(x)^3)^3,0)
scl = function(x) (x - min(x))/(max(x) - min(x))
mela1 <- mela %>%
  slice(1:9) %>%
  mutate(dist = abs(year - year[5]),scaled = scl(dist),weight = tric(scaled)
  )
mod1 <- lm(incidence ~ year,data = mela1,weights = weight) %>%
  augment(.,mela1)
mela2 <- mela %>%
  slice(10:18) %>%
  mutate(dist = abs(year - year[5]),weight = tric(scaled)
  )
mod2 <- lm(incidence ~ year,data = mela2,mela2)
mela3 <- mela %>%
  slice(19:27) %>%
  mutate(dist = abs(year - year[5]),weight = tric(scaled)
  )
mod3 <- lm(incidence ~ year,data = mela3,mela3)
mela4 <- mela %>%
  slice(28:37) %>%
  mutate(dist = abs(year - year[5]),weight = tric(scaled)
  )
mod4 <- lm(incidence ~ year,data = mela4,mela4)

主要情节：

col <- rainbow_hcl(start = 12,4,l = 20)
colB <- rainbow_hcl(start = 12,l = 100)
main <- ggplot(data = mela,aes(x = year,y = incidence)) +
# segment 1
  geom_segment(
    aes(x = 1936,xend = 1944,y = 2.115717,yend = 2.115717)) +
# segment 2
  geom_segment(
    aes(x = 1945,xend = 1953,y = 3.473217,yend = 3.473217)) +
# segment 3
  geom_segment(
    aes(x = 1954,xend = 1962,y = 1.170247,yend = 1.170247)) +
# segment 4
  geom_segment(
    aes(x = 1963,xend = 1972,y = 2.7,yend = 2.7)) +
  geom_point(data = mod1,color = col[1],shape = 1) +
  geom_point(data = mod2,color = col[2],shape = 0) +
  geom_point(data = mod3,color = col[4],shape = 5) +
  geom_point(data = mod4,color = col[3],shape = 2) +
  geom_line(data = mod1,y = .fitted),color = col[1]) +
  geom_line(data = mod2,color = col[2]) +
  geom_line(data = mod3,color = col[4]) +
  geom_line(data = mod4,color = col[3]) +
  scale_x_continuous(breaks = c(1940,1949,1958,1967))

插入

inset1 <- ggplot(data = mod1,y = weight)) +
  geom_line(color = col[1]) +
  geom_area(fill = colB[1]) +
  theme_void()
inset2 <- ggplot(data = mod2,y = weight)) +
  geom_line(color = col[12) +
  geom_area(fill = colB[2]) +
  theme_void()
inset3 <- ggplot(data = mod3,y = weight)) +
  geom_line(color = col[3]) +
  geom_area(fill = colB[3]) +
  theme_void()
inset4 <- ggplot(data = mod4,y = weight)) +
  geom_line(color = col[4]) +
  geom_area(fill = colB[4]) +
  theme_void()

问题 1： 如何放置四个 inset，使权重函数的 y = 0 位于相应 geom_segment 的高度？我希望主图坐标中的插图高度 = 2。

问题 2： 如何将每个段的颜色设置为相应插图的颜色？

解决方法

不确定我是否做对了一切。但我已经尽力了。 (; 你可以大大简化你的代码

  1. ...通过将您的模型数据绑定到一个数据框以及段的数据中。
  2. ...通过一些命名向量和scale_xxx_manual
    3. 映射美学并设置颜色和形状

对于您的插图，无需制作单独的图并尝试将它们放入主图。您可以通过额外的 geom_line 和 geom_ribbon 简单地添加它们。要获取线段的高度，将线段数据加入模型数据，以便您可以根据线段的 geom_ribbon 值设置 y 的起始值

library(tidyverse)
library(broom)
library(colorspace)

col <- setNames(col,c("mod1","mod2","mod4","mod3"))
colB <- setNames(colB,"mod3"))
shapes <- setNames(c(1,5,2),"mod3","mod4"))

mods <- list(mod1 = mod1,mod2 = mod2,mod3 = mod3,mod4 = mod4) %>% 
  bind_rows(.id = "mod")

# segments data
dseg <- tribble(
  ~mod,~x,~xend,~y,"mod1",1936,1944,2.115717,1945,1953,3.473217,1954,1962,1.170247,1963,1972,2.7,)

main <- ggplot(data = mela,aes(x = year,y = incidence)) +
  geom_segment(data = dseg,aes(x = x,xend = xend,y = y,yend = y,color = mod)) +
  geom_point(data = mods,aes(color = mod,shape = mod)) +
  geom_line(data = mods,y = .fitted,color = mod)) +
  scale_color_manual(values = col) +
  scale_shape_manual(values = shapes) +
  scale_x_continuous(breaks = c(1940,1949,1958,1967)) +
  guides(color = FALSE,shape = FALSE,fill = FALSE)

mods1 <- left_join(mods,select(dseg,mod,y),by = "mod")

# Add insets
main +
  geom_line(data = mods1,y = weight + y,color = mod,group = mod)) +
  geom_ribbon(data = mods1,ymin = y,ymax = weight + y,fill = mod,group = mod)) +
  scale_fill_manual(values = colB)

colorscolorsgeom-segmentggplot2insetsrr