[R-sig-ME] [R] lme4 Error Help: “maxstephalfit…pwrssUpdate”

[ONKELINX, Thierry]

Dear Craig,

It is better to ask questions about lme4 at r-sig-mixed-models (in cc).

Are you using a recent version of lme4? Try upgrading lme4 and see if you still get the error.

Best regards,

Thierry

ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest
team Biometrie & Kwaliteitszorg / team Biometrics & Quality Assurance
Kliniekstraat 25
1070 Anderlecht
Belgium
+ 32 2 525 02 51
+ 32 54 43 61 85
Thierry.Onkelinx op inbo.be
www.inbo.be

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~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data.
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-----Oorspronkelijk bericht-----
Van: r-help-bounces op r-project.org [mailto:r-help-bounces op r-project.org] Namens Craig O'Connell
Verzonden: maandag 28 april 2014 3:20
Aan: r-help op r-project.org
Onderwerp: [R] lme4 Error Help: “maxstephalfit…pwrssUpdate”

I am using a mixed model to assess the effects of various variables (i.e. treatment, density, visibility) on bee behavior (e.g., avoidance frequency - total avoidances per total visits; feeding frequency, and mating frequency).  Bee individuals is my random factor (n=63 different bees), whereas treatment type, animal density, and air visibility are my fixed factors.
However, when I run my models, I immediately get an error that I cannot fix.  Here is a sample of my data:
Bee   Treatment    Visits    Avoid   Feeding    Mating    Density   Visibility

1   C   5   0   5   0      5        4
2   C   4   0   3   0      5        4
3   C   3   0   3   0      5        4
...
63

1   PC  2   0   1   1      5        4
2   PC  3   0   0   3      5        4
3   PC  1   0   0   0      5        4
...
63

1   M   5   0   1   3      5        4
2   M   3   2   0   0      5        4
3   M   2   0   0   2      5        4
...
63One I create my .txt file, I being my coding in R by first loading lme4.  After that, my coding starts off as follows:
barrierdat = read.table("GLMMROW.txt", header=TRUE) barrierdat barrierdat$Visibility = as.factor(barrierdat$Visibility);
barrierdat$Density    = as.factor(barrierdat$Density);

p01.glmer = glmer(Avoidance~offset(log(Visits))+(1|Bee),            family=poisson,
                  data=egghead);  # null model; p02.glmer = glmer(Avoidance~offset(log(Visits))+(1|Bee)+Treatment,  family=poisson,
                  data=egghead);
p03.glmer = glmer(Avoidance~offset(log(Visits))+(1|Bee)+Visibility, family=poisson,
                  data=egghead);
p04.glmer = glmer(Avoidance~offset(log(Visits))+(1|Bee)+Density,    family=poisson,
                  data=egghead);However, upon immediately running my models (e.g. p01.glmer), I receive the error:
Error: (maxstephalfit) PIRLS step-halvings failed to reduce deviance in pwrssUpdate

Does anybody know what the issue is?  I ran similar data several weeks ago and had no issues.  Any Suggestions on how to proceed?

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