Error in hist.default(xa) : 'x' must be numeric

问题

I'm a complete R beginner, and am trying to do something pretty basic - make histograms of two vectors I imported from Excel.

The vectors are xa and xb. I tried hist(xa), and get the following error:

Error in hist.default(xa) : 'x' must be numeric

So I did some searching, and tried to remedy this using as.numeric(xa), and got:

Error: (list) object cannot be coerced to type 'double'

So I tried the as.list function, but it turned my vector into a matrix. Not really sure what's going on. The numbers in the vectors are all 4 digits between about -2 and +10. Any help would be greatly appreciated!

回答1:

Here's something you can try... no guarantees, since you have not given a working example:

newXa <- sapply(xa, as.numeric)
hist(newXa)

What should be done is to look at the structure of 'x'

str(x)

Then if 'xa' is how you are referring to x[['a']] you would do this:

hist( x[['a']] )

And if str(x) showed that the "a" column were a factor, one might have more success with this:

 hist( as.numeric(as.character(x[['a']]))  )

来源：https://stackoverflow.com/questions/12633586/error-in-hist-defaultxa-x-must-be-numeric