title: Non-numeric argument to mathematical function
body: <p>I want to get pvalues from a data set. I have not had any problems to use pnorm, but I have now.</p>
  
  <pre><code>data(iris)
  
  iris[,-5]&lt;- scale(as.matrix(iris[,-5]))
  
  # K-Means Cluster Analysis
  fit &lt;- kmeans(iris[,-5], 5) # 5 cluster solution
  # get cluster means 
  aggregate(iris[,-5],by=list(fit$cluster),FUN=mean)
  # append cluster assignment
  mydata &lt;- data.frame(iris, fit$cluster)
  
  pval&lt;- pnorm(iris[,-5])
  </code></pre>
  
  <p>After this, I get message of "Error in pnorm(q, mean, sd, lower.tail, log.p) : 
    Non-numeric argument to mathematical function".</p>
  
  <p>What is the problem? I do not understand why this is happening.</p>
  
  <p>Please let me know.</p>