similar to: rpois formula

Full_Name: Kjetil Kjernsmo Version: Version 1.0.0 OS: osf1 Submission from: (NULL) (129.240.28.227) Dear all, I have come across another really strange bug in rpois. If I do > rpois(1, 1000000 * rpois(1, 10000)) sometimes it hangs, and hangs... On my XP1000 alphaev6 workstation, it seems to happen more frequently than on other machines. I started a session on an older computer, and from

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)). ????? For my particular Monte Carlo, I have replaced my call to rpois with a call to the following: ?rpois. <- function(n,

Dear all, I think I must be going crazy.... If I do > mean(rpois(1000000, 14)) I get: [1] 13.50420 and again: > mean(rpois(1000000, 14)) [1] 13.49896 > mean(rpois(1000000, 14)) [1] 13.50161 > mean(rpois(1000000, 15)) [1] 14.49250 > mean(rpois(1000000, 15)) [1] 14.49897 > mean(rpois(1000000, 14.5)) [1] 13.99689 > mean(rpois(1000000, 14.5)) [1] 13.9963 This was on a platform

The R poisson random generator rpois appears to have a bug for theta 10 or larger. The sample mean of the pseudo variates is too small: sample mean approx theta - 0.5. I use Version 1.1.1 (August 15, 2000) Of R on a Dell OptiPlex computer with the Windows XP Professional operating system. Has this bug been fixed in later versions? (I found another reported rpois bug, but it appears to be

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? >>

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

On 1/20/20 12:33 PM, Martin Maechler wrote: > > It's really something that should be discussed (possibly not > here, .. but then I've started it here ...). > > The NEWS for R 3.0.0 contain (in NEW FEATURES) : > > * Functions rbinom(), rgeom(), rhyper(), rpois(), rnbinom(), > rsignrank() and rwilcox() now return integer (not double) > vectors.

On 1/20/20 4:26 AM, Martin Maechler wrote: > Coming late here -- after enjoying a proper weekend ;-) -- > I have been agreeing (with Spencer, IIUC) on this for a long > time (~ 3 yrs, or more?), namely that I've come to see it as a > "design bug" that rpois() {and similar} must return return typeof() "integer". > > More strongly, I'm actually pretty

????? This issue arose for me in simulations to estimate confidence, prediction, and tolerance intervals from glm(., family=poisson) fits embedded in a BMA::bic.glm fit using a simulate.bic.glm function I added to the development version of Ecfun, available at "https://github.com/sbgraves237/Ecfun".? This is part of a vignette I'm developing, available at

There is a problem with `rpois'. It does seem to take care about the order of the arguments. This is an example: > rpois(n=1,lambda=2) [1] 3 > rpois(lambda=2,n=1) [1] 2 0 It obviously uses the first argument as the number of samples to be drawn, which is wrong. I used Version 0.49 Beta (April 23, 1997). Fredrik

There is a problem with `rpois'. It does seem to take care about the order of the arguments. This is an example: > rpois(n=1,lambda=2) [1] 3 > rpois(lambda=2,n=1) [1] 2 0 It obviously uses the first argument as the number of samples to be drawn, which is wrong. I used Version 0.49 Beta (April 23, 1997). Fredrik

Kjetil Kjernsmo <kjetil.kjernsmo@astro.uio.no> writes: > On 8 Nov 2000, Peter Dalgaard BSA wrote: > > >I'm not at all happy with this: > > > >Solaris : > >> range(sapply(1:2000, function(n) mean(rpois(10000, 15.0)))) > >[1] 15.0524 15.3403 > > Hm, OK, so it isn't just me.... I guess it is time to file a bug report, > should I do it,

Hi there, I need some helpo with one simulation. I have a matrix of 4x21 I want ro generate 100 random Chi2 distribution but inly from the first row of my matrix. This is what I try: Option (a): >lambda=1:100 >f=function(x)chisq(4,0,x) >lapply(lambda,f) It doesn't work! option(b): >m=mean(matrix[1,]) >x<-rpois(100,lambda=m) Works, but only generates a row of 25 values.

On 2020-01-19 13:01, Avraham Adler wrote: > Crazy thought, but being that a sum of Poissons is Poisson in the sum, > can you break your ?big? simulation into the sum of a few smaller > ones? Or is the order of magnitude difference just too great? ????? I don't perceive that as feasible.? Once I found what was generating NAs, it was easy to code a function to return pseudo-random

Thanks to Luke and Avi for their comments.? I wrapped "round" around the call to "rnorm" inside my "rpois.".? For "lambda" really big, that "round" won't do anything.? However, it appears to give integers in floating point representation that are larger than .Machine$integer.max.? That sounds very much like what someone would want.?

On my Mac: str(.Machine) ... $ integer.max????????? : int 2147483647 ?$ sizeof.long????????? : int 8 ?$ sizeof.longlong????? : int 8 ?$ sizeof.longdouble??? : int 16 ?$ sizeof.pointer?????? : int 8 ????? On a Windows 10 machine I have, $ sizeof.long : int 4; otherwise the same as on my Mac. ????? Am I correct that $ sizeof.long = 4 means 4 bytes = 32 bits? log2(.Machine$integer.max)

Ugh, sounds like competing priorities. * maintain type consistency * minimize storage (= current version, since 3.0.0) * maximize utility for large lambda (= proposed change) * keep user interface, and code, simple (e.g., it would be easy enough to add a switch that provided user control of int vs double return value) * backward compatibility On 2020-01-20 12:33 p.m., Martin Maechler

On 8 Nov 2000, Peter Dalgaard BSA wrote: >Done... Great! >(This kind of behaviour has been observed on various platforms and >various compilers, sometimes getting stuck around 15.15 and sometimes >around 14.5. Others report no problems. Very strange. I've seen one >case where it apparently shifted from one regime to the other.) Yes, it does that here too.... The following is

>>>>> Martin Maechler >>>>> on Tue, 21 Jan 2020 09:25:19 +0100 writes: >>>>> Ben Bolker >>>>> on Mon, 20 Jan 2020 12:54:52 -0500 writes: >> Ugh, sounds like competing priorities. > indeed. >> * maintain type consistency >> * minimize storage (= current version, since 3.0.0) >> *

Full_Name: Kjetil Kjernsmo Version: 0.65.1 OS: Digital UNIX 4.0 Submission from: (NULL) (129.240.28.172) I'm experiencing problems with rpois. Occasionally, it draws a very high number. Yeah, I know, this is statistics, things like that does happen, but this really strange because a poisson distribution with a parameter of 3 shouldn't see the number 1932 very often, but the same,