na.strings applied to a dataframe

Question

I currently have a dataframe in which there are several rows I would like converted to \"NA\". When I first imported this dataframe from a .csv, I could use na.strings=c(\"A

Answer 1

Just assign the NA values directly.

e.g.:

x <- data.frame(a=1:5, b=letters[1:5])
# > x
#   a b
# 1 1 a
# 2 2 b
# 3 3 c
# 4 4 d
# 5 5 e

# convert the 'b' and 'd' in columb b to NA
x$b[x$b %in% c('b', 'd')] <- NA
# > x
#  a     b
# 1 1    a
# 2 2 
# 3 3    c
# 4 4 
# 5 5    e