问题
Possible Duplicate:
R seems to multiply my data by -1
I have a simple csv file. Looks like this
x y 1 2 1 3 2 1 2 3
I created it in MS Excel, saved as csv etc.
I read it using this command
ttest<--read.csv("ttest.csv", header = TRUE)
The resulting data looks like this
x y -1 -2 -1 -3 -2 -1 -2 -3
I've opened the original csv file in a text editor and it looks like it should
回答1:
The reason is that your command:
ttest<--read.csv("ttest.csv", header = TRUE)
... has an extra dash after the <- and R is interpreting this as a negative sign, and thus negating any numbers that it reads before it loads the data into ttest.
In addition, there may be some confusion between read.csv(), which is for reading comma-separated value files and read.table(), which will read files like:
x y
1 2
1 3
2 1
2 3
... which is rather more what I think your file might have looked like originally.
来源：https://stackoverflow.com/questions/14407600/read-csv-makes-everything-negative