Finding non-numeric data in an R data frame or vector

Question

I have read in some lengthy data with read.csv(), and to my surprise the data is coming out as factors rather than numbers, so I\'m guessing there must be at least one non-n

Answer 1

An alternative could be to check which entries in the vector contain any characters other than a number:

df <- data.frame(c(1,2,3,4,"five",6,7,8,"nine",10))
which(!grepl('^[0-9]',df[[1]]))
## 5 9