[ADMB Users] Correct model for counting data

Marcelo Luiz de Laia marcelolaia at gmail.com
Wed Oct 12 12:17:51 PDT 2011


I'm trying to analyze a data set from counting. By google, I found
glmmADMB package.

However, I found little information that could help me on R
environment.

My dataset are as follows:

Esp       Mat    Time  Rep  Germ  Inf
Sucupira  M02     1    1    0     0
Sucupira  M02     2    1    1     0
Sucupira  M02     3    1    1     8
Sucupira  M02     4    1    1     8
Sucupira  M02     5    1    1     9
Sucupira  M02     6    1    1     10
Sucupira  M02     7    1    1     15
Sucupira  M02     1    2    0     0
(...)
Sucupira  M02     7    3    1     10
Sucupira  M04     1    1    0     0
Sucupira  M04     2    1    0     1
(...)
Vinhatico M15CV15 7    3    5     8

Esp = Species
Mat = Stock plant (Stock plant from three different locations)
Time = Days that were analyzed
Rep = Replicate (germination boxes with 20 seeds each)
Germ = germinated seeds in each germination box (from 20)
Inf = Number of seeds with microorganisms in each germination box
(from 20)

These are a repeated measures over time, ie: on day 1 was counted how
many seeds had germinated and how many had micro-organisms. On day 2
was counted how many seeds had germinated and how many had
micro-organisms. So until the 7th.

I tried the following code:

fit = glmm.admb(Germ~Esp*Mat+Rep,random=~Rep,group="Time",
        zeroInflation=TRUE,data=ka.dat,family="poisson")

But, beyond the error:

Maximum number of iterations exceeded in dvector eigen(_CONST dmatrix&
m)
Error in glmm.admb(Germinacao ~ Especie * Matriz + Repeticao, random =
~Repeticao,  : 
  The function maximizer failed
In addition: Warning message:
running command './nbmm -maxfn 500 ' had status 1 

I'm not sure if the model proposed by me is correct. For example, the
'group' should be the Time? And the random effect would be the
Repetition (Rep)? And the family? This is a Binomial or Poison? My N
decrease over the time if germinated and/or infected seeds increase.

I also would like to see if there is any relationship between
germination and infestation for both species and for stock plants
(different places - regions).

If you have experience with this package could give some tips?

Thanks

-- 
  O___   - Marcelo
 c/  /'_ - 
(*)  \(*)- 
~~~~~~~~~- Brazil
^^^^^^^^^- Linux user number 487797



More information about the Users mailing list