t, optional</span></dt><dd><p>minimum frequency to calculate the DF spectrum</p>
</dd>
</dl>
<p><strong>Returns</strong></p>
<dl class="simple">
<dt>df_spec<span class="classifier">ndarray complex, 2D (nf,nf)</span></dt><dd><p>the complex dual-frequency cross-spectrum. Not normalized</p>
</dd>
<dt>df_cohe<span class="classifier">ndarray, 2D (nf,nf)</span></dt><dd><p>MSC, dual-freq coherence matrix. Normalized (0.0,1.0)</p>
</dd>
<dt>df_phase<span class="classifier">ndarray, 2D (nf,nf)</span></dt><dd><p>the 