依次層疊酒吧GGPLOT2 - 土壤剖面

Question

的documentation爲條形圖中ggplot2說（見例3）：當多個棒放置在同一位置

條形圖自動堆疊。填充順序的設計與圖例相匹配。

由於某種原因，第二句對我不起作用。下面是一個例子的數據集，其代表土層上述（落葉層等）和地下（實際土）：

df <- structure(list(horizon = structure(c(5L, 3L, 4L, 2L, 1L, 5L, 
3L, 4L, 2L, 1L, 5L, 3L, 4L, 2L, 1L, 5L, 3L, 4L, 2L, 1L, 5L, 3L, 
4L, 2L, 1L, 5L, 3L, 4L, 2L, 1L), .Label = c("A", "B", "F", "H", 
"L"), class = "factor"), site = structure(c(1L, 1L, 1L, 1L, 1L, 
2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L, 4L, 5L, 
5L, 5L, 5L, 5L, 6L, 6L, 6L, 6L, 6L), .Label = c("A", "B", "C", 
"D", "E", "F"), class = "factor"), value = c(2.75, 0.5, 0.25, 
-4.125, -3.375, 3.78125, 1.375, 0.625, -10.6875, -6.34375, 4.28, 
2.065, 0.68, -12.1, -10.75, 8.583333333, 4.541666667, 2.166666667, 
-10.70833333, -4.25, 7.35, 4, 1.8, -13.95, -5.175, 1.933333333, 
1.245833333, 0.641666667, -11.16666667, -2.291666667)), .Names = c("horizon", 
"site", "value"), class = "data.frame", row.names = c(NA, -30L 
)) 

現在我嘗試通過首先指定土壤層級別的順序繪製數據（即視野，自上而下地）：

require(ggplot2); require(dplyr) 
df %>% 
    mutate(horizon = factor(horizon, levels = c("L","F","H","A","B"))) %>% 
    ggplot(aes(site, value)) + geom_col(aes(fill = horizon)) + labs(y = "Soil depth (cm)") 

它爲L，F，H而不是A，B（以下GR即負值）。其原因可能不起作用的原因是，堆疊酒吧的排序從最大到最小爲site（分別爲正值和負值），然後以上下方式堆疊。它是否正確？如果是這樣的話，那麼對於我的積極價值來說，這只是巧合，這個傳說與我相信的堆疊酒吧相匹配。

我想要實現的是在圖例中疊加條形圖的順序（從頂部到底部），因此在橫截面視圖中查看土壤剖面時，我不確定如何來解決這個問題。

我曾嘗試改變總體排序行爲，但它產生同樣的情節如上：

df %>% 
    mutate(horizon = factor(horizon, levels = c("L","F","H","A","B"))) %>% 
    arrange(desc(value)) %>% 
    ggplot(aes(site, value)) + geom_col(aes(fill=horizon)) + labs(y = "Soil depth (cm)") 

df %>% 
    mutate(horizon = factor(horizon, levels = c("L","F","H","A","B"))) %>% 
    arrange(value) %>% 
    ggplot(aes(site, value)) + geom_col(aes(fill=horizon)) + labs(y = "Soil depth (cm)") 

我可能得正值和負值分別進行排序，即分別下降和上升，？

Answer 1

根據相應因子的等級對堆積條形圖進行排序。潛在的問題出現在反向堆疊的負值（從負向頂部朝向0）。爲了闡明問題讓讓所有的值負：

df %>% 
    mutate(horizon = factor(horizon, levels = c("L","F","H","B","A"))) %>% 
    ggplot(aes(site, value - 20)) + geom_col(aes(fill = horizon)) + labs(y = "Soil depth (cm)") 

一種解決方法是指定一個不同的順序水平，這將導致以期望填充次序的（在這種情況下：levels = c("L","F","H","B","A")）和手動調整使用scale_fill_discrete傳說：

df %>% 
    mutate(horizon = factor(horizon, levels = c("L","F","H","B","A"))) %>% 
    ggplot(aes(site, value)) + geom_col(aes(fill = horizon)) + labs(y = "Soil depth (cm)")+ 
    scale_fill_discrete(breaks = c("L","F","H","A","B"))