title: SAS does not recognize continuous variables
body: <p>I have imported a dataset from excel and I want to run a logistic regression, but SAS does not recognized continuous variables.
  That is the code I used:</p>
  
  <pre><code>Proc logistic data=work.heart class famhist /param=ref ref=first
  model chd = tobacco ldl typea age famhist;
  run;
  </code></pre>
  
  <p>I get the following message in Log:  </p>
  
  <pre><code>"Variable tobacco should be either numeric or specified in the CLASS statement"
  </code></pre>
  
  <p>while tobacco is a continuous variable.
  What should I do?</p>