问题
I have problems importing a .txt file into R because the number columns changes from eight to nine. Initially, my data has eight columns:
Date, Open, High, Low, Close, Volume, Open Interest, Delivery Month
Later, I add an additional column Unadjusted close. How should I import the data? Somehow the Unadjusted close column has to be ignored at the beginning. I've tried
data1 <- read.table("AD_0.TXT", sep=",", header=TRUE)
but that doesn't work.
回答1:
You need to use the fill argument in the read.table function. Suppose I have the following file
"A","B","C"
1,2,3
4,5
6,7,8
called tmp.txt. Note that row two has only two values. Then
> a = read.table("tmp.txt", sep=",", header=TRUE, fill=TRUE)
> a
A B C
1 1 2 3
2 4 5 NA
3 6 7 8
You use then standard sub-setting commands to remove (if you want to), any rows that contain NA:
> a[!is.na(a$C),]
A B C
1 1 2 3
3 6 7 8
来源：https://stackoverflow.com/questions/5402758/importing-a-txt-file-when-number-of-columns-varies