CODEWITHSUNDEEP
rdataframeformatdata.table
user8491385
user8491385

Reputation: 443

Keep Column Names the same after applying Data.table function

I have the following line of code which extracts certain columns from the data frame "Diff". When applying the data.table function the columns names get renamed V1,V2,V3 etc. How can I keep the columns names the same as before (as they appear in the Diff dataframe)?

data.table(Diff$FactSet.Fund.Code, Diff$FactsetDate.x, , Diff$DeskName.x)

Upvotes: 2

Views: 1781

Answers (1)

vestland
vestland

Reputation: 61074

Assuming that your problems arise when you go from a data.frame to a data.table, you can first turn your data.frame to a data.table in its entirety by using diff <- data.table(diff). Then you can easily subset your data.table using subset() and a list with the names of columns you want to keep. This way you'll keep your original names. Here goes:

# Libraries
library(data.frame)

# Here's dataframe with some random data
# that fits your description:
diff = data.frame(FactSet.Fund.Code=rep(c("a","b"),c(2,3)),FactsetDate.x=1:5,FactsetSomethingelse=5:1)
#class(diff)

diff = data.table(diff)
#class(diff)

# The names fo the columns you'd like to keep:
selection = c('FactSet.Fund.Code','FactsetDate.x')

# Your desired subset:
diff <- subset(diff,,selection)

# And now it should look like this:

   FactSet.Fund.Code FactsetDate.x
1:                 a             1
2:                 a             2
3:                 b             3
4:                 b             4
5:                 b             5

Upvotes: 1

Related Questions