Replacing all occurrences of a value in a data frame column [duplicate]

Question

How can I replace, for example, all "-sh2", in a column (V2) with -100, as in the following dataframe:

V1  V2  V3
p1  -sh2    13
p2  23  29
p3  17  25
p4  -sh2    34

Thanks

Start by reading this basic introductory text on vectors and assignment — Simon O'Hanlon
– Simon O'Hanlon, Commented Jan 9, 2014 at 14:39

Sven Hohenstein · Accepted Answer · 2014-01-09 14:42:21Z

4

dat$V2 <- replace(as.character(dat$V2), dat$V2 == "-sh2", "-100")

answered Jan 9, 2014 at 14:42

Sven Hohenstein

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Comments

rrs · Accepted Answer · 2014-01-09 15:35:01Z

2

There are many ways to do this. You can use the replace solution above. Or use ifelse. Or even:

my.df$V2[my.df$V2 == "-sh2"] <- -100

answered Jan 9, 2014 at 15:35

rrs

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Many thanks Simon, Sven and rrs for the perfect solutions.