传播多个列[tidyr]

Question

我想用数据在多个列上传播数据tidyr.

  dat <- data.frame(ID = rep(1,10), 
  col1 = LETTERS[seq(1,10)], 
  col2 = c(letters[seq(1,8)],NA,NA),
  col3 = c(rep(NA,8),"5",NA),
  col4 = c(rep(NA,8),NA,"value"))

预期结果是:

Out <- data.frame(t(c(1,letters[seq(1,8)],"5","value")),row.names=NULL)
colnames(Out) <- c("ID",LETTERS[seq(1,10)])

我提出了:

a <- dat %>% gather(variable, value, -(ID:col1)) %>% 
     unite(temp, col1, variable) %>% 
     spread(temp, value)
a[,-which(is.na(a))]

这是笨拙的,也改变了列名.有更好的解决方案吗？

Answer 1

我们可以使用na.rm=TRUEin gather,删除'变量' select并使用spread

library(dplyr)
library(tidyr)
gather(dat, variable, val, -(ID:col1), na.rm=TRUE) %>% 
                      select(-variable)  %>% 
                      spread(col1, val)
#  ID A B C D E F G H I     J
#1  1 d b b c b b b a 5 value

如果我们使用tidyr,类似的选择是

dat %>%
  pivot_wider(names_from = col1, values_from = str_c("col", 2:4)) %>% 
  select_if(~ any(!is.na(.)))
# A tibble: 1 x 11
#     ID col2_A col2_B col2_C col2_D col2_E col2_F col2_G col2_H col3_I col4_J
#  <dbl> <fct>  <fct>  <fct>  <fct>  <fct>  <fct>  <fct>  <fct>  <fct>  <fct> 
#1     1 a      b      c      d      e      f      g      h      5      value