Replace all particular values in a data frame

Like this:

> df[df==""]<-NA> df     A    B1 <NA>   122  xyz <NA>3  jkl  100

Since PikkuKatja and glallen asked for a more general solution and I cannot comment yet, I'll write an answer. You can combine statements as in:

> df[df=="" | df==12] <- NA> df     A    B1  <NA> <NA>2  xyz  <NA>3  jkl  100

For factors, zxzak's code already yields factors:

> df <- data.frame(list(A=c("","xyz","jkl"), B=c(12,"",100)))> str(df)'data.frame':   3 obs. of  2 variables: $ A: Factor w/ 3 levels "","jkl","xyz": 1 3 2 $ B: Factor w/ 3 levels "","100","12": 3 1 2

If in trouble, I'd suggest to temporarily drop the factors.

df[] <- lapply(df, as.character)

Here are a couple dplyr options:

library(dplyr)# all columns:df %>%   mutate_all(~na_if(., ''))# specific column types:df %>%   mutate_if(is.factor, ~na_if(., ''))# specific columns:  df %>%   mutate_at(vars(A, B), ~na_if(., ''))# or:df %>%   mutate(A = replace(A, A == '', NA))# replace can be used if you want something other than NA:df %>%   mutate(A = as.character(A)) %>%   mutate(A = replace(A, A == '', 'used to be empty'))