How to add a random effect to a linear mixed effects model?
<p>I'm analyzing the effect of Sex, Cap.Year, Cap.Location and Spawning.Season on the number of spawning sites lake trout visit (Sites.Visited). I'm trying to add a random effect variable ("Transmitter", i.e. individual fish ID) to a linear mixed effects model. See below for sample of my data.</p>

<pre><code>    &gt; head(Conc, 10)
      Transmitter Sex Sites.Visited Cap.Year Cap.Location Season.Length Spawning.Season
1  A69-1601-26770   M             2     2013   Grand Isle             P            2013
2  A69-1601-26771   F             1     2013   Grand Isle             P            2013
3  A69-1601-26773   F             2     2013   Grand Isle             P            2013
4  A69-1601-26774   M             2     2013   Grand Isle             P            2013
5  A69-1601-26776   F             4     2013   Grand Isle             P            2013
6  A69-1601-26778   M             2     2013   Grand Isle             P            2013
7  A69-1601-26784   M             1     2013   Grand Isle             P            2013
8  A69-1601-26785   F             2     2013   Grand Isle             P            2013
9  A69-1601-26786   F             2     2013   Grand Isle             P            2013
10 A69-1601-26787   M             2     2013   Grand Isle             P            2013
</code></pre>

<p>Here is my model (without the random effects variable):</p>

<pre><code>modelDDF&lt;-glm2(Sites.Visited~ factor(Sex)+factor(Cap.Year)+factor(Spawning.Season)+factor(Cap.Location), 
               family = gaussian, Conc, weights=NULL, subset=NULL, na.action=NULL, start = NULL, 
               offset=NULL, model = TRUE, method = "glm.fit2", x = FALSE, y = TRUE, contrasts = NULL,)
</code></pre>

<p>The random effect variable I'd like to add is "Transmitter". According to everything I've read, this should work:</p>

<pre><code>modelDDF&lt;-glm2(Sites.Visited~ factor(Sex)+factor(Cap.Year)+factor(Spawning.Season)+factor(Cap.Location)+(1|Transmitter), 
               family = gaussian, Conc, weights=NULL, subset=NULL, na.action=NULL, start = NULL, 
               offset=NULL, model = TRUE, method = "glm.fit2", x = FALSE, y = TRUE, contrasts = NULL,)
</code></pre>

<p>But instead, I get this error:</p>

<pre><code>Error in 1 | Transmitter : 
  operations are possible only for numeric, logical or complex types
&gt; 
</code></pre>