[R] Strange R behavior for product of two sum of integers

[David Winsemius]

On Oct 20, 2011, at 1:45 AM, Lei Jiang wrote:

> When using power operator ^, both the base and index are coerced to  
> type
> "real". The range of "real" is larger than "integer".
>
> However, an ordinary multiplication operator * offers it to two  
> integers (as
> always).
>
> So, to avoid the warning, just add "as.real(...)" to one or both  
> multipliers
> (once one multiplier is "real", the other must be coerced to "real"  
> in the
> operation):
>
>> sum(1000:1205)*as.real(sum(1000:1205))
> [1] 51581223225

That does seem to be an infelicity that ought to be fixed. Using the  
infix addition operator does that same sort of coercions, so why would  
one expect the infix multiplication operator to refuse to do it?

 > (sum(1000:1205))*(sum(1000:1204) +1205)
[1] 51581223225

 >  (sum(1000:1205))*(sum(1000:1204) +0)
[1] 51307549650

-- 
David.
>
> HTH,
> Lei
>
>
> On Wed, Oct 19, 2011 at 7:44 PM, Lafaye de Micheaux Pierre <
> lafaye at dms.umontreal.ca> wrote:
>
>> Dear gentlemen,
>>
>> Can you explain me why the following happens (any OS I think, and  
>> even on
>> 64 bits)?
>>
>>> sum(1000:1205)^2
>> [1] 51581223225
>>> sum(1000:1205)*sum(1000:1205)
>> [1] NA
>> Warning message:
>> In sum(1000:1205) * sum(1000:1205) : NAs produced by integer overflow
>>
>> Best,
>>
>> Pierre
>>
>> --
>> Pierre Lafaye de Micheaux
>> Adresse courrier:
>> Département de Mathématiques et Statistique
>> Université de Montréal
>> CP 6128, succ. Centre-ville
>> Montréal, Québec H3C 3J7
>> CANADA
>>
>> Adresse physique:
>> Département de Mathématiques et Statistique
>> Bureau 4249, Pavillon André-Aisenstadt
>> 2920, chemin de la Tour
>> Montréal, Québec H3T 1J4
>> CANADA
>>
>> Tél.: (00-1) 514-343-6607 / Fax: (00-1) 514-343-5700
>> lafaye at dms.umontreal.ca
>> http://www.biostatisticien.eu
>>
>> ______________________________**________________
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>> >
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>>
>
>
>
> -- 
> Lei Jiang
>
> Center for Computation and Technology/
> Department of Computer Science
> Louisiana State University
>
> E-mail: ljiang at cct.lsu.edu
>
> 	[[alternative HTML version deleted]]
>
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David Winsemius, MD
West Hartford, CT