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<div style="direction: ltr;font-family: Tahoma;color: #000000;font-size: 10pt;">Dear GlmmADMB-users,<br>
<br>
I am running models with a binary respons variable (0/1) and wanted to see if there was a linear trend through time (day of the season 1-117). I am using individual identity as a random variable in all my models. I am currently using R 2.14.1
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Tahoma; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; font-size: medium;">
<span class="Apple-style-span" style="font-size: 13px; line-height: 15px; white-space: pre-wrap;">(64-bit)</span></span> and glmmadmb v.0.7.2.5<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Arial; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; font-size: medium;"><span class="Apple-style-span" style="font-family: 'Lucida Console'; font-size: 13px; line-height: 15px; white-space: pre-wrap;">.</span></span><br>
The problem is that when I run my simplest model : SYN ~ sesday + (1|RINGNR) family="binomial", I get the following warnings:<br>
<br>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Arial; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; font-size: medium;"><span class="Apple-style-span" style="font-family: 'Lucida Console'; font-size: 13px; line-height: 15px; white-space: pre-wrap;">
<pre tabindex="0" class="GJWPQFQDK4" style="font-family: 'Lucida Console'; font-size: 10pt ! important; outline-style: none; border-style: none; white-space: pre-wrap ! important; margin: 0px; line-height: 1.2;"><span class="GJWPQFQDF4">Warning messages:
</span><span class="GJWPQFQDF4">1: In glmmadmb(SYN ~ sesday + (1 | RINGNR), family = "binomial", data = helgesmr) :
Convergence failed:log-likelihood of gradient= -0.0461339
</span><span class="GJWPQFQDF4">2: In print.glmmadmb(list(n = 1548L, q = 1103L, formula = SYN ~ sesday + :
Object has a large gradient component<br><br><br><span style="font-family: Tahoma;">Summary of the model:<br><br><br></span></span><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Arial; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; font-size: medium;"><span class="Apple-style-span" style="font-family: 'Lucida Console'; font-size: 13px; line-height: 15px; white-space: pre-wrap;"><pre tabindex="0" class="GJWPQFQDK4" style="font-family: 'Lucida Console'; font-size: 10pt ! important; outline-style: none; border-style: none; white-space: pre-wrap ! important; margin: 0px; line-height: 1.2;">Call:
glmmadmb(formula = SYN ~ sesday + (1 | RINGNR), data = helgesmr,
family = "binomial")
Coefficients:
Estimate Std. Error z value Pr(>|z|)
(Intercept) -13.14000 0.99477 -13.21 < 2e-16 ***
sesday 0.04878 0.00888 5.49 3.9e-08 ***
---
Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1
Number of observations: total=1548, RINGNR=1103
Random effect variance(s):
Group=RINGNR
Variance StdDev
(Intercept) 249.3 15.79
Log-likelihood: -566.279 </pre></span></span><span class="GJWPQFQDF4"> </span></pre>
</span></span><br>
<div>Is this a "overly cautious" warning from glmmadmb or a more serious problem?<br>
I also have to say that when I add a second order term (sesday^2) everything works fine. I am just a bit curious why the "simpler" model ran into trouble.<br>
<br>
I really like all the new functionality of glmmADMB so I would like to thank the <br>
developers!<br>
<br>
Cheers,<br>
<br>
Håkon<br>
<div style="font-family: Tahoma; font-size: 13px;"><font size="2"><span style="font-size: 10pt;">---------------------------------------------------------
<br>
Håkon Holand, PhD.Student<br>
Centre for Conservation Biology<br>
Department of Biology<br>
Norwegian University of Science and Technology<br>
NO-7491 Trondheim<br>
Norway</span></font></div>
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