r – Cant draw Histogram, x must be numeric

Because of the thousand separator, the data will have been read as non-numeric. So you need to convert it:

 we <- gsub(,, , we)   # remove comma
 we <- as.numeric(we)      # turn into numbers

and now you can do

 hist(we)

and other numeric operations.

Note that you could as well plot directly from ce (after the comma removing) using the column name :

hist(ce$Weight)

(As opposed to using hist(ce[1]), which would lead to the same must be numeric error.)

This also works for a database query result.

Use the dec argument to set , as the decimal point by adding:

 ce <- read.table(file.txt, header = TRUE, dec = ,)