[R] glm.nb

[Ronaldo Reis Jr.]

Hi,

I make some simulations with rnbinom and try to test with glm.nb.

But in some data set the glm.nb fail.

Look:

pop <- rnbinom(n=1000,size=1,mu=0.05)
> glm.nb(pop~1,maxit=1000)
Error in while ((it <- it + 1) < limit && abs(del) > eps) { : 
 missing value where TRUE/FALSE needed

look some pop charactetistics:
> summary(pop)
   Min. 1st Qu.  Median    Mean 3rd Qu.    Max. 
  0.000   0.000   0.000   0.052   0.000   2.000

> hist(pop,plot=F)
$breaks
 [1] 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

$counts
 [1] 949   0   0   0  50   0   0   0   0   1

$intensities
 [1] 4.744999 0.000000 0.000000 0.000000 0.250000 0.000000 0.000000 0.000000
 [9] 0.000000 0.005000

$density
 [1] 4.744999 0.000000 0.000000 0.000000 0.250000 0.000000 0.000000 0.000000
 [9] 0.000000 0.005000

$mids
 [1] 0.1 0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9

My question is:

Why this error occour and how to solve this problem without increase the mu 
parameter in rnbinom?


Thanks fo all

Ronaldo

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