We have seen many questions regarding How to save the decimal places while converting factors to numbers such as this and this. But I did not see anything that do the same with character data instead of factor data. Below is what I tried without success:
f1 <- c("402313.01399128098", "402896.30908451998", "403165.63827027398", "403169.06116369402", "402891.96329268801", "402239.74412469601", 
        "402271.54950727499", "402313.01399128098")
as.numeric(as.character(f1)) # does not work
f2 <- as.factor(f1) 
as.numeric(as.character(f2)) # my decimals are GONE
f3 <- levels(f2) 
as.numeric(f3) # my decimals are gone again
I get this
[1] 402239.7 402271.5 402313.0 402892.0 402896.3 403165.6 403169.1
Update after the answer/comments:
There was no loss of decimal places. But I do not know why it was not showing.  With options(digits = 15) I could see all the decimals.
Lesson: You may run options() before you decide to ask such questions. 
 
     
    