[Rd] rpois(9, 1e10)

Spencer Graves @pencer@gr@ve@ @end|ng |rom prod@y@e@com
Sun Jan 19 16:42:59 CET 2020

On 2020-01-19 09:34, Benjamin Tyner wrote:
>> ------------------------------------------------------------------------
>> Hello, All:
>>         Consider:
>> Browse[2]> set.seed(1)
>> Browse[2]> rpois(9, 1e10)
>> NAs produced[1] NA NA NA NA NA NA NA NA NA
>>         Should this happen?
>>         I think that for, say, lambda>1e6, rpois should return rnorm(.,
>> lambda, sqrt(lambda)).
> But need to implement carefully; rpois should always return a 
> non-negative integer, whereas rnorm always returns numeric...

       Thanks for the reply.

       However, I think it's not acceptable to get an NA from a number 
that cannot be expressed as an integer.  Whenever a randomly generated 
number would exceed .Machine$integer.max, the choice is between 
returning NA or a non-integer numeric.  Consider:

 > 2*.Machine$integer.max
[1] 4294967294
 > as.integer(2*.Machine$integer.max)
[1] NA
Warning message:
NAs introduced by coercion to integer range

       I'd rather have the non-integer numeric.


More information about the R-devel mailing list