pure function hann_eval(this, bin) result(rst)  
</h3>
  <p>Evaluates the window function.</p>

  <h4>Arguments</h4>
      <table class="table table-striped varlist">
    <thead>
      <tr>
        <th>Type</th>
<th>Intent</th><th>Optional</th>        <th>Attributes</th>
        <th></th>
        <th>Name</th>
        <th></th>
    </thead>
    <tbody>
        <tr>
            <td>
              <span class="anchor" ></span>
              class(<a href='../type/hann_window.html'>hann_window</a>),
          