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<table border="0" summary="Simple list" class="simplelist_nottable_last">
  <tr>
    <td>
      <a href="constructor_examples_rational.html#copy">Copy an rational object</a>
    </td>
  </tr>
  <tr>
    <td>
      <a href="constructor_examples_rational.html#xml_file">Construct an rational object by loading the object from a file</a>
    </td>
  </tr>
  <tr>
    <td>
      <a href="constructor_examples_rational.html#rational">Construct an rational object from an parfrac object</a>
    </td>
  </tr>
  <tr>
    <td>
      <a href="constructor_examples_rational.html#pzmodel">Construct an rational object from a pole/zero model</a>
    </td>
  </tr>
  <tr>
    <td>
      <a href="constructor_examples_rational.html#coeffs">Construct an rational object from numerator and denominator coefficients</a>
    </td>
  </tr>
  <tr>
    <td>
      <a href="constructor_examples_rational.html#plist">Construct an rational object from a parameter list object (PLIST)</a>
    </td>
  </tr>
</table>

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<hr>
<h2 class="title"><a name="copy"></a>Copy an rational object</h2>
<p>The following example creates a copy of an rational object (blue command).</p>
<div class="fragment"><pre class="programlisting">
>> ra1 = rational([1 2 3], [4 5 6 7], <span class="string">'my rational'</span>);
<span class="blue">>> ra2 = rational(ra1)</span>
---- rational 1 ----
model:    my rational
num:      [1 2 3]
den:      [4 5 6 7]
iunits:   []
ounits:   []
--------------------
</pre></div>
<br></br>
<p>REMARK: The following command copies only the handle of an object and doesn't create a copy of the object (as above). This means that everything that happens to the copy or original happens to the other object.</p>
<div class="fragment"><pre class="programlisting">
>> ra1 = rational()
---- rational 1 ----
model:    none
num:      []
den:      []
iunits:   []
ounits:   []
--------------------
>> ra2 = ra1;
>> ra2.setName(<span class="string">'my new name'</span>)
---- rational 1 ----
model:    <span class="string">my new name</span>
num:      [1 2 3]
den:      [4 5 6 7]
iunits:   []
ounits:   []
--------------------
</pre></div>
<br></br>
<p>If we display ra1 again then we see that the property 'name' was changed although we only have changed ra2.</p>
<div class="fragment"><pre class="programlisting">
>> ra1
---- rational 1 ----
model:    <span class="string">my new name</span>
num:      [1 2 3]
den:      [4 5 6 7]
iunits:   []
ounits:   []
--------------------
</pre></div>


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<hr>
<h2 class="title"><a name="xml_file"></a>Construct an rational object by loading the object from a file</h2>
<p>The following example creates a new rational object by loading the object from disk.</p>
<div class="fragment"><pre class="programlisting">
ra = rational(<span class="string">'rational_object.mat'</span>)
ra = rational(<span class="string">'rational_object.xml'</span>)
</pre></div>
<p>or in a <tt>PLIST</tt></p>
<div class="fragment"><pre class="programlisting">
pl = plist(<span class="string">'filename'</span>, <span class="string">'rational_object.xml'</span>);
ra = rational(pl)
</pre></div>


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<hr>
<h2 class="title"><a name="rational"></a>Construct an rational object from an parfrac object</h2>
<p>The following example creates a new rational object from an parfrac object.</p>
<div class="fragment"><pre class="programlisting">
>> pf = parfrac([1 2+1i 2-1i], [6 1+3i 1-3i], 3, <span class="string">'my parfrac'</span>)
---- parfrac 1 ----
model:    my parfrac
res:      [1;2+i*1;2-i*1]
poles:    [6;1+i*3;1-i*3]
dir:      3
pmul:     [1;1;1]
iunits:   []
ounits:   []
-------------------
>> ra = rational(pf)
---- rational 1 ----
model:    rational(my parfrac)
num:      [3 -19 30 -110]
den:      [1 -8 22 -60]
iunits:   []
ounits:   []
--------------------
</pre></div>
<p>or in a plist</p>
<div class="fragment"><pre class="programlisting">
>> pf = parfrac([1 2+1i 2-1i], [6 1+3i 1-3i], 3, <span class="string">'my parfrac'</span>);
>> pl = plist(<span class="string">'rational'</span>, rat)
>> ra = rational(pl)
</pre></div>


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<hr>
<h2 class="title"><a name="pzmodel"></a>Construct an rational object from a pole/zero model</h2>
<p>The following example creates a new rational object from a pole/zero model.</p>
<div class="fragment"><pre class="programlisting">
>> pzm = pzmodel(1, {1 2 3}, {4 5}, <span class="string">'my pzmodel'</span>)
---- pzmodel 1 ----
    name: my pzmodel
    gain: 1
   delay: 0
  iunits: []
  ounits: []
pole 001: (f=1 Hz,Q=NaN)
pole 002: (f=2 Hz,Q=NaN)
pole 003: (f=3 Hz,Q=NaN)
zero 001: (f=4 Hz,Q=NaN)
zero 002: (f=5 Hz,Q=NaN)
-------------------
>> ra = rational(pzm)
---- rational 1 ----
model:    rational(None)
num:      [0.0012  0.0716  1]
den:      [0.0001  0.0036  0.0401  0.2122  1]
iunits:   []
ounits:   []
--------------------
</pre></div>
<p>or in a plist</p>
<div class="fragment"><pre class="programlisting">
>> pzm = pzmodel(1, {1 2 3}, {4 5}, <span class="string">'my pzmodel'</span>)
>> pl  = plist(<span class="string">'pzmodel'</span>, pzm)
>> ra  = rational(pl)
</pre></div>


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<hr>
<h2 class="title"><a name="coeffs"></a>Construct an rational object from numerator and denominator coefficients</h2>
<p>The following example creates a new rational direct from the numerator and denominator coefficients.</p>
<div class="fragment"><pre class="programlisting">
>> num    = [1 2 3];
>> den    = [4 5 6];
>> name   = <span class="string">'my rational'</span>;
>> iunits = <span class="string">'Hz'</span>;
>> ounits = <span class="string">'V'</span>;

>> ra = rational(num, den)
>> ra = rational(num, den, name)
>> ra = rational(num, den, name, iunits, ounits)
---- rational 1 ----
model:    my rational
num:      [1 2 3]
den:      [4 5 6]
iunits:   [Hz]
ounits:   [V]
--------------------
</pre></div>


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<hr>
<h2 class="title"><a name="plist"></a>Construct an rational object from a parameter list  (<tt>plist</tt>)</h2>
<p>Constructs an rational object from the description given in the parameter list.</p>

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<table border="0" summary="Simple list" class="simplelist_nottable_last">
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    <td>
      <a href="constructor_examples_rational.html#hostname">Use the key word 'hostname'</a>
    </td>
  </tr>
  <tr>
    <td>
      <a href="constructor_examples_rational.html#pl_coeffs">Use the key word 'num' or 'den'</a>
    </td>
  </tr>
</table>
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<hr>
<h3 class="title"><a name="hostname"></a>Use the key word 'hostname'</h3>
<p>Construct an rational object by retrieving it from a LTPDA repository.</p>
<p>The relevant parameters are:</p>
<p>
  <table cellspacing="0" border="0" cellpadding="2" class="simplelist_nottable_last" width="80%">
    <colgroup>
      <col width="25%"/>
      <col width="75%"/>
    </colgroup>
    <thead>
      <tr valign="top">
        <th class="subcategorylist">Key</th>
        <th class="subcategorylist">Description</th>
      </tr>
    </thead>
    <tbody>
      <tr valign="top">
        <td>
          <p>'hostname'</p>
        </td>
        <td>
          <p>the repository hostname. [default: 'localhost']</p>
        </td>
      </tr>
      <tr valign="top">
        <td>
          <p>'database'</p>
        </td>
        <td>
          <p>The database name [default: 'ltpda']</p>
        </td>
      </tr>
      <tr valign="top">
        <td>
          <p>'id'</p>
        </td>
        <td>
          <p>A vector of object IDs. [default: []]</p>
        </td>
      </tr>
      <tr valign="top">
        <td>
          <p>'cid'</p>
        </td>
        <td>
          <p>Retrieve all rational objects from a particular collection</p>
        </td>
      </tr>
      <tr valign="top">
        <td>
          <p>'binary'</p>
        </td>
        <td>
          <p>Set to 'yes' to retrieve from stored binary representation (not always available). [default: yes]</p>
        </td>
      </tr>
    </tbody>
  </table>
</p>
<div class="fragment"><pre class="programlisting">
pl = plist(<span class="string">'hostname'</span>, <span class="string">'130.75.117.67'</span>, <span class="string">'database'</span>, <span class="string">'ltpda_test'</span>, <span class="string">'id'</span>, 1)
a1 = rational(pl)
</pre></div>


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<hr>
<h3 class="title"><a name="direct_terms"></a>Use the key word 'num' or 'den'</h3>
<p>Construct an rational object direct from the coefficients.<br></br>
The relevant parameters are:</p>
<p>
  <table cellspacing="0" border="0" cellpadding="2" class="simplelist_nottable_last" width="80%">
    <colgroup>
      <col width="25%"/>
      <col width="75%"/>
    </colgroup>
    <thead>
      <tr valign="top">
        <th class="subcategorylist">Key</th>
        <th class="subcategorylist">Description</th>
      </tr>
    </thead>
    <tbody>
      <tr valign="top">
        <td>
          <p>'num'</p>
        </td>
        <td>
          <p>numerator coefficients [default: []]</p>
        </td>
      </tr>
      <tr valign="top">
        <td>
          <p>'den'</p>
        </td>
        <td>
          <p>denominator coefficients [default: []]</p>
        </td>
      </tr>
    </tbody>
  </table>
</p>
<p>You can also specify optional parameters:</p>
<p>
  <table cellspacing="0" border="0" cellpadding="2" class="simplelist_nottable_last" width="80%">
    <colgroup>
      <col width="25%"/>
      <col width="75%"/>
    </colgroup>
    <thead>
      <tr valign="top">
        <th class="subcategorylist">Key</th>
        <th class="subcategorylist">Description</th>
      </tr>
    </thead>
    <tbody>
      <tr valign="top">
        <td>
          <p>'name'</p>
        </td>
        <td>
          <p>name of the rational object [default: 'none']</p>
        </td>
      </tr>
      <tr valign="top">
        <td>
          <p>'xunits'</p>
        </td>
        <td>
          <p>unit of the x-axis</p>
        </td>
      </tr>
      <tr valign="top">
        <td>
          <p>'yunits'</p>
        </td>
        <td>
          <p>unit of the y-axis</p>
        </td>
      </tr>
    </tbody>
  </table>
</p>
<div class="fragment"><pre class="programlisting">
num    = [1 2 3];
den    = [4 5 6];
name   = <span class="string">'my rational'</span>;
iunits = <span class="string">'Hz'</span>;
ounits = <span class="string">'V'</span>;

pl = plist(<span class="string">'num'</span>, num, <span class="string">'den'</span>, den);
ra = rational(pl)
---- rational 1 ----
model:    None
num:      [1 2 3]
den:      [4 5 6]
iunits:   []
ounits:   []
--------------------

pl = plist(<span class="string">'num'</span>, num, <span class="string">'den'</span>, den, <span class="string">'name'</span>, name, <span class="string">'iunits'</span>, iunits, <span class="string">'ounits'</span>, ounits);
pf = rational(pl)
---- rational 1 ----
model:    my rational
num:      [1 2 3]
den:      [4 5 6]
iunits:   [Hz]
ounits:   [V]
--------------------
</pre></div>