Beware: 2 is not always 2 in R

May 14, 2013
By

(This article was first published on Are you cereal? » R, and kindly contributed to R-bloggers)

This post is minimalistic.
Consider this:

x <- 2.0000001

Now let's have look at what's inside x:

x
> [1] 2

But is it really true?

x==2
> [1] FALSE

Here you go.
A colleague of mine was once ruined by this for an entire day before we realized what was going on.
So, how to find out what REALLY is the value of x?
Try:

as.character(x)
> [1] "2.0000001"

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