title: Chi square test error "Chi-squared approximation may be incorrect"
body: <p>I ran a chi-squared test in R and the results are:</p>
  
  <pre><code>crianza = matrix(c(1,1,0,12,12,7,2,1,0,0,1,0,0,0,5,
        0,0,0,1,1,2,0,0,3,0,0,0,13,35,29,0,0,1,10,
        0,0,1,0,0,0,0,0),ncol=3,byrow=TRUE)
  colnames (crianza) = c("Neonate","Juevenile","Adult")
  rownames (crianza) = c("C.acronotus","C.limbatus","C.obscurus","C.perezi",
   "C.porosus","C.falciformis","G.cuvier","G.cirratum","M.canis",
   "R.porosus","R.lalandii","S.lewini","S.mokarran","S.tiburo")    
  crianza = as.table(crianza)
  
  Pearson's Chi-squared test
  
  data:  crianza
  X-squared = NaN, df = 26, p-value = NA
  
  Warning message:
  In chisq.test(crianza) : Chi-squared approximation may be incorrect
  </code></pre>
  
  <p>Does anyone know why it gave a warning? Is it because I am using a wrong method?</p>