Convert factors with brackets to numeric in a data.frame

Question

I have a column in a dataframe that has geocoordinate values that get converted to a factor on import that look like this

[ [ -106.2432752 , 39.0077354]]
[ [ -106.1867662 , 38.8326113]]

I want to convert them to a list of numbers but cant figure out a way. I've tried removing the brackets with gsub but it returns strings.

Check this: http://stackoverflow.com/questions/3418128/how-to-convert-a-factor-to-an-integer-numeric-without-a-loss-of-information — Julian Wittische, Sep 10 '15 at 00:02
add a dput() on your data so it is easier to see how R is currently storing it. — jeremycg, Sep 10 '15 at 01:58

score 1 · Accepted Answer · answered Sep 10 '15 at 06:35

Try it. gregexpr locates where is the pattern. Then regmatches extracts the patterns it returns a list. Bind those lists by row and convert them with as.numeric function in a apply.

> tmp
                           V1
1 [ [ -106.2432752 , 39.0077354]]
2 [ [ -106.1867662 , 38.8326113]]

apply(do.call(rbind,regmatches(as.character(tmp[,1]),gregexpr("[-]*[0-9]*[.]{1}[0-9]+",as.character(tmp[,1])))),2,as.numeric)

         [,1]     [,2]
[1,] -106.2433 39.00774
[2,] -106.1868 38.83261

Convert factors with brackets to numeric in a data.frame

1 Answers1