Replace strings in R column

Question

I have a dataframe which includes the factor column "Year".

The observations in "Year" looks like this:

etc

I want to eventually convert "Year" into class integer. First, however, I need to drop the "y" from each observations, so that the data takes the form:

etc

The years are all in the interval y1995-y2007.

How would I do this?

I'm struggling if to close this a dupe of this http://stackoverflow.com/questions/13594223/number-values-include-comma-how-do-i-make-these-numeric — David Arenburg, Apr 07 '15 at 11:17

akrun · Answer 1 · 2015-04-07T11:12:18.273

3

You can try sub to remove the first non-numeric element.

df1$Year <- as.numeric(sub('y', '', df1$Year, fixed=TRUE))

data

df1 <- data.frame(Year=paste0('y', c(1995, 1995, 1997, 1997, 1999, 2007,
           1995)))

edited Apr 07 '15 at 11:12

answered Apr 07 '15 at 11:08

akrun

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@DavidArenburg Based on the example showed, `y` is the `prefix` – akrun Apr 07 '15 at 11:12

codingEnthusiast · Accepted Answer · 2015-04-07T11:18:06.850

2

This has a simple solution:

temp <- sub("y", "", df$Year)

and if you'd like to replace the old vector:

df$Year <- sub("y", "", df$Year)

and afterwards if you'd like to convert that column into numeric (it will still hold string, although you won't be able to see it right away):

df$Year <- sub("y", "", df$Year)
df$Year <- as.numeric(df$Year)

edited Apr 07 '15 at 11:18

answered Apr 07 '15 at 11:10

codingEnthusiast

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score 0 · Answer 3 · edited Apr 07 '15 at 11:55

0

You can try to use function str_replace in package stringr.

Year <- str_replace(Year, "y", "")

edited Apr 07 '15 at 11:55

dimitris_ps

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answered Apr 07 '15 at 11:44

Xinting WANG

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Replace strings in R column

3 Answers3

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