将数据帧及其组合名称的所有成对组合复制到新的数据帧中

您可以将其放在长格式中:

library(tidyr)
library(dplyr)
 
 df %>%
  # add as column row names
  mutate(col1 = rownames(.)) %>%
  # from wide to long format
  pivot_longer( -col1, values_to = "Value", names_to = "col2") %>%
  # create the combination in the format you need
  mutate(step = paste0(col1,col2)) %>%
  # select useful columns
  select(step, Value) %>%
  # sort by step
  arrange(step)

# A tibble: 25 x 2
   step  Value
   <chr> <dbl>
 1 a1a1      4
 2 a1a2     56
 3 a1a3      4
 4 a1a4      6
 5 a1a5     54
 6 a2a1      2
 7 a2a2      1
 8 a2a3      6
 9 a2a4     15
10 a2a5     94
# ... with 15 more rows

您可以将数据转换为 table 回到a data.frame .

df2 <- as.data.frame(as.table(as.matrix(df)))
df2[order(df2$Var1), ]

#    Var1 Var2 Freq
# 1    a1   a1    4
# 6    a1   a2   56
# 11   a1   a3    4
# 16   a1   a4    6
# 21   a1   a5   54
# 2    a2   a1    2
# 7    a2   a2    1
# 12   a2   a3    6
# 17   a2   a4   15
# 22   a2   a5   94
# ...