Question

我正在尝试使用ggalluvial来跟踪学生在学期内的学术路径，并了解学生如何随着时间的推移改变课程。

这是我的数据集示例：

structure(list(id = c("1", "2", "6", "8", "9", "10", "11", "12", 
"14", "15", "1", "2", "6", "8", "9", "10", "11", "12", "14", 
"15", "1", "2", "6", "8", "9", "10", "11", "12", "14", "15", 
"1", "2", "6", "8", "9", "10", "11", "12", "14", "15", "1", "2", 
"6", "8", "9", "10", "11", "12", "14", "15", "1", "2", "6", "8", 
"9", "10", "11", "12", "14", "15", "1", "2", "6", "8", "9", "10", 
"11", "12", "14", "15", "1", "2", "6", "8", "9", "10", "11", 
"12", "14", "15"), 
curr = c("CURR1", "CURR1", "CURR1", "CURR1", 
    "CURR1", "CURR1", "CURR1", "CURR1", "CURR1", "CURR1", "CURR3", 
    "CURR3", "CURR3", "CURR3", "CURR3", "CURR3", "CURR3", "CURR3", 
    "CURR3", "CURR3", "CURR5", "CURR5", "CURR5", "CURR5", "CURR5", 
    "CURR5", "CURR5", "CURR5", "CURR5", "CURR5", "CURR7", "CURR7", 
    "CURR7", "CURR7", "CURR7", "CURR7", "CURR7", "CURR7", "CURR7", 
    "CURR7", "CURR9", "CURR9", "CURR9", "CURR9", "CURR9", "CURR9", 
    "CURR9", "CURR9", "CURR9", "CURR9", "CURR11", "CURR11", "CURR11", 
    "CURR11", "CURR11", "CURR11", "CURR11", "CURR11", "CURR11", "CURR11", 
    "CURR13", "CURR13", "CURR13", "CURR13", "CURR13", "CURR13", "CURR13", 
    "CURR13", "CURR13", "CURR13", "CURR15", "CURR15", "CURR15", "CURR15", 
    "CURR15", "CURR15", "CURR15", "CURR15", "CURR15", "CURR15"), 
        value = c("ISDS", "ISDS", "GBUS", "ISDS", "GBUS", "ISDS", 
        "ACCT", "GBUS", "ITF", "MGT", "ISDS", "ISDS", "GBUS", "ISDS", 
        "MKT", "ISDS", "ACCT", "GBUS", "ITF", "MGT", "ISDS", "ISDS", 
        "ISDS", "ISDS", "MKT", "ISDS", "ACCT", "GBUS", "ISDS", "MGT", 
        "ISDS", "ISDS", "ISDS", "ISDS", "ISDS", "ISDS", "ACCT", "GBUS", 
        "ISDS", "ISDS", "ISDS", "ISDS", "ISDS", NA, "ISDS", "ISDS", 
        "ACCT", "ISDS", "ISDS", "ISDS", "ISDS", "ISDS", "ISDS", "ISDS", 
        "ISDS", "ISDS", "ISDS", "ISDS", "ISDS", "ISDS", "ISDS", NA, 
        "ISDS", "ISDS", "ISDS", NA, "ISDS", "ISDS", "ISDS", "ISDS", 
        "ISDS", NA, "ISDS", "ISDS", "ISDS", NA, "ISDS", "ISDS", "ISDS", 
        NA)), class = "data.frame", row.names = c(NA, -80L), .Names = c("id", 
    "curr", "value"))

id =学生ID
CURR = semester id
value =课程编号

我想映射：

CURR（时间变量），到x轴
value到y轴的不同高度
每个value的{{1}}到流量宽度的计数

图表应该显示他们随着时间推移“流动”哪个课程。

这就是我到目前为止所做的事情，这很不错

CURR

x轴看起来不错，但ggplot(as.data.frame(ff2), aes(x=curr, axis1=value, group=id)) + geom_alluvium(aes(fill = value))并不能反映课程的不同重量，也不能跟随学生的“流动”。

Answer 1

抱歉延误。我刚刚合并了一个实验分支，包括一个单独的geom，用于绘制轴之间的“流量”，而不是跨越整个图表的完整“alluvia”，以及一堆新参数。这假设在OP中为ff2分配structure()调用，使用以下代码可以描述您所描述的情节。

# keep the values of 'curr' in their proper order
ff2$curr <- factor(ff2$curr, levels = unique(ff2$curr))
ggplot(ff2, aes(
  # position aesthetics:
  # 'x' as in 'geom_bar()'
  # 'stratum' and 'alluvium' specific to ggalluvial
  x = curr, stratum = value, alluvium = id,
  # apply 'fill' colors to both flows and strata
  fill = value
)) +
  # flow parameters:
  # 'lode.guidance' says how to arrange splines in each stratum
  # 'aes.flow' says which axis determines flow aesthetics
  geom_flow(lode.guidance = "rightleft", aes.flow = "forward") +
  geom_stratum() +
  # include text labels at each stratum
  geom_text(stat = "stratum")

感谢您指出这种需求，特别是以一致的方式处理NA！

Answer 2

尝试以下方法。它不华丽，但它的工作原理。您可以使用基本图形来清理它。

安装以下软件包（如果尚未安装），然后加载它们：

library(alluvial) 
library(tidyr)

编辑您的数据：

ff2$value[is.na(ff2$value)] <- "None" # Replace NAs with a category so they're not lost
ff2$curr <- as.numeric(substr(ff2$curr, 5, nchar(ff2$curr))) # Change your term labels to numeric for easy & correct ordering
ff3 <- spread(ff2, curr, value, fill = "None") #spread your df from long to wide format

按学生为您的图表着色，以便更轻松地跟踪：

cl <- colors(distinct = TRUE)
color_palette <- sample(cl, length(ff3$id))

简介：

alluvial(ff3[,2:9], 
         freq = 8,
         col = color_palette,
         blocks = T,
         xw = 0.2,# makes the ribbons a bit wavier
         axis_labels = c("Term1","Term2", "Term3","Term4","Term5","Term6", "Term7","Term8"))

如何将单个路径映射到冲积图？

2 个答案: