CODEWITHSUNDEEP
r
Little
Little

Reputation: 3477

how to convert a vector of characters to quantitative data

I have a vector with the following data:

data<-c('ab','ab','ab','cd','cd','cd','ef','ef')

how can I convert that data by using R so that it gets transformed with the following pattern:

ab=1
cd=2
ef=3

so that the vector will be converted to:

data=[1,1,1,2,2,2,3,3]

Upvotes: 1

Views: 48

Answers (2)

akrun
akrun

Reputation: 887431

Another option is match

match(data, unique(data))
#[1] 1 1 1 2 2 2 3 3

Or in place of unique(data), you can specify the vector of elements to match.

match(data, c('ab', 'cd', 'ef'))

Upvotes: 3

MrFlick
MrFlick

Reputation: 206391

That's basically what a "factor" is in R. you can do

as.numeric(factor(data, levels=c("ab","cd","ef")))

You could also use a named lookup vector

vv<-c(ab=1, cd=2, ef=3)
vv[data]
# or unname(vv[data]) if the names really bother you

Upvotes: 2

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