title: Argument "No" is missing, with no default
body: <p>I need to assign values in the variable "TRTCD1" in two different classes as 1 and 2, based on the condition as stated in the R programming code below.</p>
  
  <pre><code>z$Treatment1.class&lt;-with(z, ifelse(TRTCD1 == 0 &amp; TRTCD1 == 40, 1,
      ifelse(TRTCD1 &gt;= 10 &amp; TRTCD1 &lt;= 30 &amp; TRTCD1 == 50, 2)))
  </code></pre>
  
  <p>On running these code, I am getting the error:</p>
  
  <blockquote>
    <p>Argument "No" is missing, with no default</p>
  </blockquote>
  
  <p>Here, <code>Treatment1.class</code> is a new variable in table <code>z</code> which holds the output of the class.</p>
  
  <p>How to fix this issue?</p>