问题
I am reading in some files created by another program. The program populates entries with missing values with the number -99.9.
I am speeding up some code from using base read.table() to fread() from the data.table package to read in these data files. I am able to use na.strings=c(-99.9) in read.table, but fread does not seem to accept numeric arguments for na.strings. The string counterpart, na.strings=c("-99.9"), does not work, and gives me the error: 'na.strings' is type '.
Can I make fread read in the number -99.9 as NA?
回答1:
If you read it in as dt change those values to NA afterwards.
dt[dt == -99.9] <- NA
problem solved?
来源：https://stackoverflow.com/questions/22331552/read-in-certain-numbers-as-na-in-r-with-data-tablefread