title: Filter by conditions for multiple columns in R
body: <p>I need to filter by conditions when <code>Plan_Year</code> is <code>1 less than</code> <code>YEAR</code> and all rows of <code>NA</code> in CAT column.</p>
  
  <p>I have the following code:</p>
  
  <pre><code>Table &lt;- Table %&gt;% filter(YEAR == Plan_Year+1)
  </code></pre>
  
  <p>How can I include/modify the code above to obtain all rows with NA in CAT column?</p>
  
  <p>Thanks in advance. </p>
  
  <p>Table: </p>
  
  <pre><code>YEAR     CAT      Plan_Year
  1998     NA       NA
  1998     125-1    1997    
  1998     171-2    1997
  1998     NA       NA  
  .
  .
  2017     114-1    202
  </code></pre>