如何只保留行的最大值,并将其他值转换为NA?

我们可以使用 apply 环行( MARGIN = 1 )及 replace 不等于 max 具有 NA ,将转置指定回原始对象

df[] <- t(apply(df, 1, function(x) replace(x, x != max(x, na.rm = TRUE), NA)))

或者 rowMaxs

library(matrixStats)
i1 <- !!rowSums(!is.na(df))
df[i1,] <-  replace(df[i1,], df[i1,] != rowMaxs(as.matrix(df[i1,]), 
                na.rm = TRUE)[col(df[i1,])], NA)

或者使用 dplyr

library(dplyr)
library(purrr)
df %>% 
  mutate(new = reduce(., pmax, na.rm = TRUE)) %>% 
  transmute_at(vars(starts_with('col')), ~ replace(., .!= new, NA))

你可以用 purrr::pmap_df

purrr::pmap_df(df, ~{
      vec <- c(...)
      ifelse(vec != max(vec, na.rm = TRUE), NA, vec)
})

# A tibble: 6 x 3
#   cola  colb  colc
#  <dbl> <dbl> <dbl>
#1    NA     7    NA
#2    NA    NA    NA
#3    NA    NA    10
#4    NA    NA    NA
#5     1    NA    NA
#6    NA     6     6