用ggplot填充R中兩條黃土平滑線之間的區域

Question

我想知道如何填充 ggplot 中黃土平滑線之間的區域。

以下數據框用於圖片：

    x         y      ymin     ymax grp     ydiff
1   1  3.285614  3.285614 10.14177 min 6.8561586
2   1 10.141773  3.285614 10.14177 max 6.8561586
3   2  5.061879  5.061879 11.24462 min 6.1827368
4   2 11.244615  5.061879 11.24462 max 6.1827368
5   3  8.614408  8.614408 13.45030 min 4.8358931
6   3 13.450301  8.614408 13.45030 max 4.8358931
7   4  6.838143  6.838143 12.34746 min 5.5093150
8   4 12.347458  6.838143 12.34746 max 5.5093150
9   5 10.390673 10.390673 14.55314 min 4.1624713
10  5 14.553144 10.390673 14.55314 max 4.1624713
11  6 12.166937 12.166937 15.65599 min 3.4890495
12  6 15.655987 12.166937 15.65599 max 3.4890495
13  7 13.943202 13.943202 16.75883 min 2.8156277
14  7 16.758830 13.943202 16.75883 max 2.8156277
15  8  5.950011  5.950011 11.79604 min 5.8460259
16  8 11.796037  5.950011 11.79604 max 5.8460259
17  9 17.495731 17.495731 18.96452 min 1.4687841
18  9 18.964515 17.495731 18.96452 max 1.4687841
19 10 15.719466 15.719466 17.86167 min 2.1422059
20 10 17.861672 15.719466 17.86167 max 2.1422059
21 11 19.271996 19.271996 20.06736 min 0.7953623
22 11 20.067358 19.271996 20.06736 max 0.7953623

以下來源產生一個帶有法線（未平滑）的圖形：

ggplot(intdf) + 
    geom_point(aes(x=x, y=y, colour=grp)) +
    geom_ribbon(aes(x=x, ymin=ymin, ymax=ymax), fill="grey", alpha=.4) +
    geom_line(aes(x=x, y=y, colour=grp))

其中 x 和 y 是連續數值。 ymin 和 ymax 每個都包含來自位置 x 處的綠線和紅線的 y 值。

現在我想平滑線條。 我只是使用以下代碼執行此操作：

ggplot(intdf) + 
    stat_smooth(aes(x=x, y=ymin, colour="min"), method="loess", se=FALSE) +
    stat_smooth(aes(x=x, y=ymax, colour="max"), method="loess", se=FALSE)

這給出了以下情節：

但是我沒有設法填充這兩條線之間的區域。 我嘗試擬合黃土模型並使用預測值，但我想我完全使用了錯誤的預測變量。

誰能告訴我如何填充平滑線之間的區域？

預先感謝丹尼爾

Answer 1

從繪圖對象中獲取黃土平滑數據並用於geom_ribbon可能解決方案：

# create plot object with loess regression lines
g1 <- ggplot(df) + 
  stat_smooth(aes(x = x, y = ymin, colour = "min"), method = "loess", se = FALSE) +
  stat_smooth(aes(x = x, y = ymax, colour = "max"), method = "loess", se = FALSE)
g1

# build plot object for rendering 
gg1 <- ggplot_build(g1)

# extract data for the loess lines from the 'data' slot
df2 <- data.frame(x = gg1$data[[1]]$x,
                  ymin = gg1$data[[1]]$y,
                  ymax = gg1$data[[2]]$y) 

# use the loess data to add the 'ribbon' to plot 
g1 +
  geom_ribbon(data = df2, aes(x = x, ymin = ymin, ymax = ymax),
              fill = "grey", alpha = 0.4)

Answer 2

本身不是答案，而是如果您想從 Henrik 運行答案，可以先借用和運行一些代碼。

library(tidyverse)

df <- tribble(
~row, ~x, ~y,    ~ymin,   ~ymax,  ~grp, ~ydiff,
1,   1,  3.285614,  3.285614, 10.14177, min, 6.8561586,
2,   1, 10.141773,  3.285614, 10.14177, max, 6.8561586,
3,   2,  5.061879,  5.061879, 11.24462, min, 6.1827368,
4,   2, 11.244615,  5.061879, 11.24462, max, 6.1827368,
5,   3,  8.614408,  8.614408, 13.45030, min, 4.8358931,
6,   3, 13.450301,  8.614408, 13.45030, max, 4.8358931,
7,   4,  6.838143,  6.838143, 12.34746, min, 5.5093150,
8,   4, 12.347458,  6.838143, 12.34746, max, 5.5093150,
9,   5, 10.390673, 10.390673, 14.55314, min, 4.1624713,
10,  5, 14.553144, 10.390673, 14.55314, max, 4.1624713,
11,  6, 12.166937, 12.166937, 15.65599, min, 3.4890495,
12,  6, 15.655987, 12.166937, 15.65599, max, 3.4890495,
13,  7, 13.943202, 13.943202, 16.75883, min, 2.8156277,
14,  7, 16.758830, 13.943202, 16.75883, max, 2.8156277,
15,  8,  5.950011,  5.950011, 11.79604, min, 5.8460259,
16,  8, 11.796037,  5.950011, 11.79604, max, 5.8460259,
17,  9, 17.495731, 17.495731, 18.96452, min, 1.4687841,
18,  9, 18.964515, 17.495731, 18.96452, max, 1.4687841,
19, 10, 15.719466, 15.719466, 17.86167, min, 2.1422059,
20, 10, 17.861672, 15.719466, 17.86167, max, 2.1422059,
21, 11, 19.271996, 19.271996, 20.06736, min, 0.7953623,
22, 11, 20.067358, 19.271996, 20.06736, max, 0.7953623
)