```r
x <- 1:4 + 0.1
(x <- x - 0.1) # looks like integer, doesn't it?
```

```
## [1] 1 2 3 4
```

```r
## here's the suggestion from the help to test if x contains integers
is.wholenumber <-
  function(x, tol = .Machine$double.eps^0.5)  abs(x - round(x)) < tol

## so are they whole numbers?
is.wholenumber(x)
```

```
## [1] TRUE TRUE TRUE TRUE
```

```r
## apparently YES!

## but not the whole numbers they appear to be?
as.integer(x)
```

```
## [1] 1 2 3 3
```

```r
trunc(x)
```

```
## [1] 1 2 3 3
```

```r
floor(x)
```

```
## [1] 1 2 3 3
```

```r
LETTERS[x]
```

```
## [1] "A" "B" "C" "C"
```

```r
## I have a better idea!
is.integery <-
  function(x, tol = .Machine$double.eps^0.5)  all(abs(x - trunc(x)) < tol)

is.integery(x)
```

```
## [1] FALSE
```