问题
I have the following data set D7
name sex_age eye_color height
1 J M.34 Other 61
2 A F.55 Blue 59
3 T M.76 Brown 51
4 D F.19 Other 57
I want to separate the column sex_age into sex column and age column, so I type
separate(D7,sex_age,c('sex','age'),sep='.')
But it generates
name sex age eye_color height
1 J Other 61
2 A Blue 59
3 T Brown 51
4 D Other 57
Warning message:
Too many values at 4 locations: 1, 2, 3, 4
Also, when I modify my original data set D7 into D8
name sex_age eye_color height
1 J M_34 Other 61
2 A F_55 Blue 59
3 T M_76 Brown 51
4 D F_19 Other 57
And I type D7 %>% separate(sex_age,c('sex','age'),sep="_") it gives
name sex age eye_color height
1 J M.34 <NA> Other 61
2 A F.55 <NA> Blue 59
3 T M.76 <NA> Brown 51
4 D F.19 <NA> Other 57
Warning message:
Too few values at 4 locations: 1, 2, 3, 4
Did I misuse the separate function? I am very puzzled. Thank you for any suggestions.
回答1:
since sep= argument considers regex and . is a special character, therefore we need to have \\ before such special characters such that they are read as normal characters
separate(df, sex_age, into = c("sex", "age"), sep = "\\.")
来源：https://stackoverflow.com/questions/41837430/warning-too-many-few-values-for-using-tidyr-packages-in-r