><span class="p">])</span>
    <span class="n">invMAab</span> <span class="o">=</span> <span class="n">np</span><span class="o">.</span><span class="n">linalg</span><span class="o">.</span><span class="n">inv</span><span class="p">(</span><span class="n">MAab</span><span class="p">)</span>    
    
    <span class="c1">#-------------------------------------------------</span>
    <span class="c1"># setup EEW reference field and default background field (Lr should be equal to Lb):</span>
    <span class="c1"