r - geom_bar 基于值使用 geom_point 颜色对数据进行分组

Question

我想将显示 sect 值的 geom_point 添加到我的分组 geom_bar 中，显示基于条件数据的点颜色的 perc 值
我的数据是这样的:

```structure(list(year = c(2019, 2019, 2019, 2018, 2018, 2018, 2017, 
2017, 2017, 2020, 2020, 2020), ques = c("q1", "q2", "q3", "q1", 
"q2", "q3", "q1", "q2", "q3", "q1", "q2", "q3"), sect = c(94.25, 
99, 86.33, 94.19, 92.21, 90.42, 98.88, 89.31, 82.76, 82.06, 75.46, 
59.39), perc = c(88.79, 94.71, 89.46, 89.69, 81.29, 84.1, 90.18, 
89.1, 73.38, 70.66, 97, 75.99), diff = c(-5.46, -4.29, 3.13, 
-4.5, -10.92, -6.32, -8.7, -0.21, -9.38, -11.4, 21.54, 16.6), 
    ci = c(12.76572759, 12.76572759, 12.76572759, 12.76572759, 
    12.76572759, 12.76572759, 12.76572759, 12.76572759, 12.76572759, 
    12.76572759, 12.76572759, 12.76572759)), class = c("spec_tbl_df", 
"tbl_df", "tbl", "data.frame"), row.names = c(NA, -12L), spec = structure(list(
    cols = list(year = structure(list(), class = c("collector_double", 
    "collector")), ques = structure(list(), class = c("collector_character", 
    "collector")), sect = structure(list(), class = c("collector_double", 
    "collector")), perc = structure(list(), class = c("collector_double", 
    "collector")), diff = structure(list(), class = c("collector_double", 
    "collector")), ci = structure(list(), class = c("collector_double", 
    "collector"))), default = structure(list(), class = c("collector_guess", 
    "collector")), skip = 1), class = "col_spec"))

表是这样的:

```    year ques   sect  perc   diff    ci
   <dbl> <chr> <dbl> <dbl>  <dbl> <dbl>
 1  2019 q1     94.2  88.8  -5.46  12.8
 2  2019 q2     99    94.7  -4.29  12.8
 3  2019 q3     86.3  89.5   3.13  12.8
 4  2018 q1     94.2  89.7  -4.5   12.8
 5  2018 q2     92.2  81.3 -10.9   12.8
 6  2018 q3     90.4  84.1  -6.32  12.8
 7  2017 q1     98.9  90.2  -8.7   12.8
 8  2017 q2     89.3  89.1  -0.21  12.8
 9  2017 q3     82.8  73.4  -9.38  12.8
10  2020 q1     82.1  70.7 -11.4   12.8
11  2020 q2     75.5  97    21.5   12.8
12  2020 q3     59.4  76.0  16.6   12.8

简单的代码:

```df %>% 
  ggplot(aes(fill=ques, y = perc, x = year)) +
  geom_bar(position="dodge", stat="identity")+
  geom_point()

我想要的颜色条件是:

```df <- df %>%
  mutate(
    color = case_when(
      diff >= ci ~ "green",
      diff <= -ci ~ "red",
      TRUE ~ "grey"
    )
  )

作为第一步，我无法让点出现在相关条上: this shows points vertically but I would like them horizontal over relevant years因此，我将非常感谢您帮助显示相关年份的点数，并结合颜色条件以在 diff >= ci 时显示绿色，红色 <= - ci 和灰色均不显示。希望这是有道理的，谢谢

Answer 1

您可以使用 position_dodge在 geom_point调用以将点与条形匹配。要获得正确的颜色，您可以映射新列 color到色标并添加对 scale_color_identity 的调用.
如果我正确理解你的逻辑，你的数据框中的任何点都不会变成红色，因为 diff 的值都没有。小于 -12.8

df %>%   
  mutate(color = case_when(diff >= ci ~ "green",
                           diff <= -ci ~ "red",
                           TRUE ~ "gray20")) %>%
  ggplot(aes(fill=ques, y = perc, x = year)) +
  geom_bar(position="dodge", stat="identity")+
  geom_point(aes(color = color), 
             position = position_dodge(width = 0.9), size = 3) +
  scale_color_identity()