[R] round() and negative digits

[(Ted Harding)]

On 09-Oct-11 00:46:58, Carl Witthoft wrote:
> 
> On 10/8/11 6:11 PM, (Ted Harding) wrote:
> 
>> Carl Witthoft's serendipitous discovery is a nice example
>> of how secrets can be guessed by wondering "what if ... ?".
>> So probably you don;t need to tell the secrets.
>>
>> Taking the "negative digits" to their logical extreme:
>>
>>    round(654.321,2)
>>    # [1] 654.32
>>    round(654.321,1)
>>    # [1] 654.3
>>    round(654.321,0)
>>    # [1] 654
>>    round(654.321,-1)
>>    # [1] 650
>>    round(654.321,-2)
>>    # [1] 700
>>    round(654.321,-3)
>>    # [1] 1000
>>    round(654.321,-4)
>>    # [1] 0
>>
>> which is what you'd logically expect (but is it what you
>> would intuitively expect?).
>>
> Oh, oh, somebody's going all metaphysical on us.

Nor should one forget the rounding rules (not OS-dependent
in this case, I think ... ?):

  round(5000,-4)
  # [1] 0
  round(15000,-4)
  # [1] 20000

Ted.

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Date: 09-Oct-11                                       Time: 08:59:58
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