在 R 中重塑一组列的多个副本 Wide > Long 和 Long > Wide

你真的应该至少提供你的数据......无论如何，这里有一个tidyverse-solution，使用tidyr和dplyr：

library(tidyverse)

df <- tribble(~patient, ~line, ~inserted, ~complications,
          1,"peripheral", "01/02/17", "none",
          1,"peripheral", "04/02/17", "blocked")

# this prefix preserves the order of your variables:
names(df)[-1] <- c("[1]line", "[2]inserted", "[3]complications")

df_wide <- 
  df %>% 
  group_by(patient) %>% 
  mutate(nr = seq_len(n())) %>% # number of observations for each patient
  gather(key = key, value = value, -patient, -nr) %>% # make Long
  arrange(nr, key) %>% # sort by nr and variable name to keep you order
  unite(key, nr, key, sep = ".") %>% # paste variable number and variable name
  mutate(key = factor(key, levels = unique(key))) %>% # tells spread to preserve order
  spread(key = key, value = value) # make wide again

# remove the prefix from above
names(df_wide) <- names(df_wide) %>% 
               gsub(pattern = "\\[\\d{1}\\]", 
               replacement = "")

df_wide

  patient   `1.line` `1.inserted` `1.complications`   `2.line` `2.inserted` `2.complications`
*   <dbl>      <chr>        <chr>             <chr>      <chr>        <chr>             <chr>
1       1 peripheral     01/02/17              none peripheral     04/02/17           blocked

反过来说：

df_long <- 
  df_wide %>%
  gather(key = key, value = value, -patient) %>% 
  separate(key, into = c("nr", "key")) %>% 
  spread(key = key, value = value) %>% 
  select(patient, line, inserted, complications)

df_long

  patient       line inserted complications
*   <dbl>      <chr>    <chr>         <chr>
1       1 peripheral 01/02/17          none
2       1 peripheral 04/02/17       blocked