ormat data.frame with new factor variable(s) describing the original columns</p>
    
    <h2 class="hasAnchor" id="see-also"><a class="anchor" href="#see-also"></a>See also</h2>

    <p>Other helping_functions: <code><a href='internal_field.html'>internal_field</a></code>,
  <code><a href='invert_stack.html'>invert_stack</a></code>, <code><a href='lfief.html'>lfief</a></code>,
  <code><a href='modify_levels.html'>modify_levels</a></code></p>
    

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