[R] Numbers that look equal, should be equal, but if() doesn

(Ted Harding) Ted.Harding at nessie.mcc.ac.uk
Thu May 29 01:03:19 CEST 2003


On 28-May-03 Barry Rowlingson wrote:
>   Oh, why not just go one step further, and redefine the == operator!
> 
>   "==" <- function(x,y){equal.enough(x,y)}
> 
> before:
>  > (.1+.2)==.3
> [1] FALSE
> 
> after:
>  > (.1+.2)==.3
> [1] TRUE
> 
>   This requires a slight modification to equal.enough, which I will not
> list here, so that people dont _actually_ do this. It just ensures that
> equal.enough doesn't go all infinitely recursive on us.
> 
>   Next time on useless R tips: 1 + 1 = 3

At which point I am unable to resist quoting:

  "2 plus 2 is never equal to 5 -- even for large values of 2".

Ted.


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Date: 29-May-03                                       Time: 00:03:19
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