Operation on new data.table affects old data.table

Asked Feb 20 '16 at 07:33

Active Feb 20 '16 at 07:33

Viewed 61 times

I'm having trouble with the data.table package in R (v1.9.6). I'm not sure what I'm doing wrong. Any help is much appreciated.

I create a data.table and then assign this to a new variable. So now I have two data.tables. I then perform an operation on the second data.table. However this operation is also performed on the original data.table as well. Is this a bug or a feature of the package? or am I doing something horribly wrong?

a<-data.table(x=1:100,y=1:100)

b<-a

b[,x:=2]

head(a)

head(b)

asked Feb 20 '16 at 07:33

mat

3

You may need `b <- copy(a)` and it should work as expected. – akrun Feb 20 '16 at 07:44
Thanks for the quick response guys. copy(a) does work :) – mat Feb 20 '16 at 07:46

Operation on new data.table affects old data.table

0 Answers0