[R] comparison operator, decimals, and signif()

Thomas Lumley tlumley at u.washington.edu
Mon May 23 15:51:32 CEST 2005


On Sat, 21 May 2005, Nick Drew wrote:
>
> What does signif() do to my object called "testMean"
> so that the comparison now evaluates to TRUE?
>
>> signif(testMean, 3) == 82.9
> [1] TRUE
>

It rounds to 3 significant digits.

  An even more reliable approach is
    round(testMean*10) == 829
since 829 is an integer and exactly representable.

 	-thomas




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