ntegration from zero to w.</p>
<p>We use Chebychev quadrature for the numerical integration.</p>
<p><em>Parameters</em></p>
<dl class="simple">
<dt>vn<span class="classifier">ndarray [npts,kspec]</span></dt><dd><p>DPSS to calculate eigenvalues</p>
</dd>
<dt>w<span class="classifier">float</span></dt><dd><p>the bandwidth (= time-bandwidth product/ndata)</p>
</dd>
<dt>atol<span class="classifier">float, optional</span></dt><dd><p>absolute error tolerance for the integration. this should
be set to 10**-n, wher