在ggforce :: geom_parallel_sets上订购y轴

Question

使用ggforce软件包的开发版本，我可以按照以下方式创建一个Sankey图表（来自文档）

data <- reshape2::melt(Titanic)
data <- gather_set_data(data, 1:4)

ggplot(data, aes(x, id = id, split = y, value = value)) +
  geom_parallel_sets(aes(fill = Sex), alpha = 0.3, axis.width = 0.1) +
  geom_parallel_sets_axes(axis.width = 0.1) +
  geom_parallel_sets_labels(colour = 'white')

我正在努力解决的问题是，y轴变量的排序方式不是默认值，而是按字母顺序排列。例如，更改图表，使Adult出现在图表顶部附近，下方为Child。

在应用gather_set_data之前，我尝试重新调整因素，并在应用y后重新调整gather_set_data变量，但似乎都不起作用。我也尝试将它们定义为字符并按不同顺序排序，但这似乎也不起作用。

任何帮助都将不胜感激。

Answer 1

不确定您对ggforce的处理方式，因为我不使用此套餐。我认为解决方案是重新调整你提到的因素，但这似乎并不适合你。但是，这适用于ggalluvial。此外，有一个参数reverse允许您反转顺序（按字母顺序/反向字母顺序）。见下文：

默认排序

library(ggplot2)
library(ggalluvial)

df <- as.data.frame(Titanic)

ggplot(as.data.frame(df),
       aes(weight = Freq,
           axis1 = Survived, axis2 = Sex, axis3 = Class)) +
  geom_alluvium(aes(fill = Class),
                width = 0, knot.pos = 1/4, reverse = FALSE) +
  guides(fill = FALSE) +
  geom_stratum(width = 1/8, reverse = FALSE) +
  geom_text(stat = "stratum", label.strata = TRUE, reverse = FALSE) +
  scale_x_continuous(breaks = 1:3, labels = c("Survived", "Sex", "Class")) +
  ggtitle("Titanic survival by class and sex")

反向排序

ggplot(as.data.frame(df),
       aes(weight = Freq,
           axis1 = Survived, axis2 = Sex, axis3 = Class)) +
  geom_alluvium(aes(fill = Class),
                width = 0, knot.pos = 1/4, reverse = TRUE) +
  guides(fill = FALSE) +
  geom_stratum(width = 1/8, reverse = TRUE) +
  geom_text(stat = "stratum", label.strata = TRUE, reverse = TRUE) +
  scale_x_continuous(breaks = 1:3, labels = c("Survived", "Sex", "Class")) +
  ggtitle("Titanic survival by class and sex")

重新调平因子

df$Class <- factor(df$Class, levels = c("3rd", "1st", "Crew", "2nd"))

ggplot(as.data.frame(df),
       aes(weight = Freq,
           axis1 = Survived, axis2 = Sex, axis3 = Class)) +
  geom_alluvium(aes(fill = Class),
                width = 0, knot.pos = 1/4, reverse = FALSE) +
  guides(fill = FALSE) +
  geom_stratum(width = 1/8, reverse = FALSE) +
  geom_text(stat = "stratum", label.strata = TRUE, reverse = FALSE) +
  scale_x_continuous(breaks = 1:3, labels = c("Survived", "Sex", "Class")) +
  ggtitle("Titanic survival by class and sex")

Answer 2

如何将y变量转换为因子呢？

    titanic <- reshape2::melt(Titanic)
    titanic <- gather_set_data(titanic, 1:4)
    titanic$y <- factor(titanic$y, levels=c("Adult", "Child", "1st", "2nd", "3rd", "Crew", "Male", "Female", "Yes", "No"))
    ggplot(titanic, aes(x, id = id, split = y, value = value)) +
        geom_parallel_sets(aes(fill = Sex), alpha = 0.3, axis.width = 0.1) +
        geom_parallel_sets_axes(axis.width = 0.1) +
        geom_parallel_sets_labels(colour = 'white')