[Rd] rpois(9, 1e10)

Avraham Adler @vr@h@m@@d|er @end|ng |rom gm@||@com
Sun Jan 19 17:28:00 CET 2020


Technically, lambda can always be numeric. It is the observations which
must be integral.

Would hitting everything larger than maxint or maxlonglong with floor or
round fundamentally change the distribution? Well, yes, but enough that it
would matter over process risk?

Avi

On Sun, Jan 19, 2020 at 11:20 AM Benjamin Tyner <btyner using gmail.com> wrote:

> So imagine rpois is changed, such that the storage mode of its return
> value is sometimes integer and sometimes numeric. Then imagine the case
> where lambda is itself a realization of a random variable. Do we really
> want the storage mode to inherit that randomness?
>
>
> On 1/19/20 10:47 AM, Avraham Adler wrote:
> > Maybe there should be code for 64 bit R to use long long or the like?
> >
> > On Sun, Jan 19, 2020 at 10:45 AM Spencer Graves
> > <spencer.graves using prodsyse.com <mailto:spencer.graves using prodsyse.com>>
> wrote:
> >
> >
> >
> >     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.
> >
> >
> >            Spencer
> >
> >     ______________________________________________
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> >
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>
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