title: tukeys HSD tets for two way ANOVA in R
body: <p>I have been analyzing my data in R using two way ANOVA followed by Tukey HSD test. I am looking for effect of temperature and sex on development time. I was able to do two way ANOVA but having problem with post hoc test.
  I used following code: </p>
  
  <pre><code>a &lt;- aov(larval.time~temp*sex, mydata=R.data) #for two way anova
  TukeyHSD(a) #for post hoc test
  </code></pre>
  
  <p>I got following error message for post hoc code:</p>
  
  <pre><code>Error in rep.int(n, length(means)) : unimplemented type 'NULL' in 'rep3' 
  </code></pre>
  
  <p>In addition:</p>
  
  <pre><code>    Warning messages: 
   1: In replications(paste("~", xx), data = mf) : non-factors ignored: Temp 
   2: In replications(paste("~", xx), data = mf) : non-factors  ignored: Temp, sex
  </code></pre>
  
  <p>Can somebody please help me with this?</p>