[R] what don't I get about numeric/double comparisons in R way?

[Peter Dalgaard]

Peter Ehlers wrote:

>> actual_mean <- mean( range)
>> actual_sd <- sd( range)
>> expected_mean <- 218.213483146067
>> expected_sd <- 159.277118043936
>>
...
> Your code is not reproducible, but it seems fairly clear
> that you haven't yet read the help pages for identical()
> and all.equal(); or, if you have, you haven't done so
> very carefully. For ?identical, you'll find this:
...

Shorter version: "Do not rely on exact equality in floating-point 
arithmetic."

Instead use something like abs(actual_mean - expected_mean) < tol.

-- 
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