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−<p>
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−  The LTPDA toolbox contains a class (<tt>pzmodel</tt>) for creating and using pole/zero models. 
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−  The <it>pole/zero model helper GUI</it> allows the user to visualise the pole/zero model as it's
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−  being designed. It also allows the user to quickly see how the corresponding IIR filter 
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−  (<tt>miir</tt> object) will look for different sample rates.
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−</p>	
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−<p>
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−  To start the pole/zero model helper:
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−  <div class="fragment">
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−    <pre>
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−      >> pzmodel_helper
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−</pre>
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−  </div>
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−  or click the appropriate button on the LTPDA Launch Bay.
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−</p>
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−<p>
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−  Once the GUI is loaded, you will see the following figure:
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−</p>
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−<br>
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−<img src="images/pzmodel_helper.png" alt="pzmodel helper" border="3">
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−<br>
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−<p>
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−  You can add poles and zeros to the model by entering the frequency (and Q) in the edit boxes, then click
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−  <tt>Add pole</tt> or <tt>Add zero</tt> as appropriate. The response is then updated in the response axes.   
+
−</p>
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−<br>
+
−<img src="images/pzmodel_helper_eg1.png" alt="pzmodel helper" border="3">
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−<br>
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−