R语言中按行堆叠两个数据集，重复展示相同subject_id

需要合并两个数据集df1和df2，使每个subject_id对应的两条记录（分别来自df1的m类型和df2的c类型）上下排列。尝试用full_join(df1, df2, by = "subject_id")得到的是列合并结果，不符合需求。

数据集结构 #

df1 #

df1 <- structure (list(
  subject_id = c("191-5467", "191-6784", "191-3457", "191-0987", "191-1245", "191-1945"), 
  m_or_c = c("m","m","m","m","m","m"),
  edta_code = c("EDTA45", "EDTA79", "EDTA20", "EDTA66", "EDTA12", "EDTA74"), 
  ipv = c("0", "3", "2", "2", "1", "2")), 
  class = "data.frame", row.names = c(NA, -6L))

df2 #

df2 <- structure (list(
  subject_id = c("191-5467", "191-6784", "191-3457", "191-0987", "191-1245", "191-1945"), 
m_or_c = c("c","c","c","c","c","c"),
  edta_code = c("EDTA49", "EDTA95", "EDTA20", "EDTA68", "EDTA89", "EDTA30"), 
  ipv = c("1", "4", "6", "4", "1", "3")), 
  class = "data.frame", row.names = c(NA, -6L))

尝试的代码 #

df3 <- full_join(df1, df2, by = "subject_id")

当前问题 #

上述代码会将两个数据集按subject_id列合并，生成包含edta_code.x、edta_code.y等后缀的列，不是需要的行堆叠形式。

期望输出 #

每行对应一条记录，相同subject_id重复出现，结构如下：

你需要的是行堆叠合并，而非列连接。可以用以下两种方法实现：

方法1：使用dplyr::bind_rows() #

bind_rows()可以直接将结构相同的数据集按行合并，之后按subject_id排序即可：

library(dplyr)

df3 <- bind_rows(df1, df2) %>% 
  arrange(subject_id)

方法2：使用基础R的rbind() #

如果两个数据集列名完全一致，基础R的rbind()也能实现相同效果，再手动排序：

df3 <- rbind(df1, df2)
df3 <- df3[order(df3$subject_id), ]

结果验证 #

执行上述代码后，df3的结构与你期望的输出一致：每个subject_id对应两条记录（m和c类型），按行排列。

内容的提问来源于stack exchange，提问作者Thandi