Add numeric ID corresponding with a string ID in R

Question

I need to create a new column with numeric ID's which is corresponding to a column with string ID. I want it to look like this:

Numeric ID    String ID
1           2RRRRkbihdUTz/X
1           2RRRRkbihdUTz/X
1           2RRRRkbihdUTz/X
2           A09mqMKPnBgUf
2           A09mqMKPnBgUf
2           A09mqMKPnBgUf
2           A09mqMKPnBgUf
3           AaULuZXJWriMXM
3           AaULuZXJWriMXM
3           AaULuZXJWriMXM

What function can I use to generate the Numeric ID, which is the same for rows with the same string ID?

Try with `match` i.e. `with(dfn, match(StringID, unique(StringID)))` — akrun, Feb 20 '18 at 09:35

score 1 · Accepted Answer · answered Feb 20 '18 at 09:36

1

We can use match to create the 'NumericID'

with(dfn, match(StringID, unique(StringID)))

Or another option is to convert to factor with levels specified as the unique values and then coerce it to integer

with(dfn, as.integer(factor(StringID, levels = unique(StringID))))

answered Feb 20 '18 at 09:36

akrun

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Thank you, the first function worked perfectly! – Martin Brummerstedt Feb 20 '18 at 09:45

Add numeric ID corresponding with a string ID in R

1 Answers1