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<div class="section" id="wavelets">
<span id="ref-wavelets"></span><h1>Wavelets<a class="headerlink" href="#wavelets" title="Permalink to this headline">¶</a></h1>
<div class="section" id="wavelet-families">
<h2>Wavelet <code class="docutils literal"><span class="pre">families()</span></code><a class="headerlink" href="#wavelet-families" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pywt.families">
<code class="descclassname">pywt.</code><code class="descname">families</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#pywt.families" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns a list of available built-in wavelet families. Currently the built-in
families are:</p>
<ul class="simple">
<li>Haar (<code class="docutils literal"><span class="pre">haar</span></code>)</li>
<li>Daubechies (<code class="docutils literal"><span class="pre">db</span></code>)</li>
<li>Symlets (<code class="docutils literal"><span class="pre">sym</span></code>)</li>
<li>Coiflets (<code class="docutils literal"><span class="pre">coif</span></code>)</li>
<li>Biorthogonal (<code class="docutils literal"><span class="pre">bior</span></code>)</li>
<li>Reverse biorthogonal (<code class="docutils literal"><span class="pre">rbio</span></code>)</li>
<li><cite>“Discrete”</cite> FIR approximation of Meyer wavelet (<code class="docutils literal"><span class="pre">dmey</span></code>)</li>
</ul>
<p><strong>Example:</strong></p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span>
<span class="gp">>>> </span><span class="k">print</span> <span class="n">pywt</span><span class="o">.</span><span class="n">families</span><span class="p">()</span>
<span class="go">['haar', 'db', 'sym', 'coif', 'bior', 'rbio', 'dmey']</span>
</pre></div>
</div>
</dd></dl>
</div>
<div class="section" id="built-in-wavelets-wavelist">
<h2>Built-in wavelets - <code class="docutils literal"><span class="pre">wavelist()</span></code><a class="headerlink" href="#built-in-wavelets-wavelist" title="Permalink to this headline">¶</a></h2>
<dl class="function">
<dt id="pywt.wavelist">
<code class="descclassname">pywt.</code><code class="descname">wavelist</code><span class="sig-paren">(</span><span class="optional">[</span><em>family</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#pywt.wavelist" title="Permalink to this definition">¶</a></dt>
<dd><p>The <a class="reference internal" href="#pywt.wavelist" title="pywt.wavelist"><code class="xref py py-func docutils literal"><span class="pre">wavelist()</span></code></a> function returns a list of names of the built-in
wavelets.</p>
<p>If the <em>family</em> name is <code class="docutils literal"><span class="pre">None</span></code> then names of all the built-in wavelets
are returned. Otherwise the function returns names of wavelets that belong
to the given family.</p>
<p><strong>Example:</strong></p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span>
<span class="gp">>>> </span><span class="k">print</span> <span class="n">pywt</span><span class="o">.</span><span class="n">wavelist</span><span class="p">(</span><span class="s">'coif'</span><span class="p">)</span>
<span class="go">['coif1', 'coif2', 'coif3', 'coif4', 'coif5']</span>
</pre></div>
</div>
<p>Custom user wavelets are also supported through the <a class="reference internal" href="#pywt.Wavelet" title="pywt.Wavelet"><code class="xref py py-class docutils literal"><span class="pre">Wavelet</span></code></a> object
constructor as described below.</p>
</dd></dl>
</div>
<div class="section" id="wavelet-object">
<h2><code class="docutils literal"><span class="pre">Wavelet</span></code> object<a class="headerlink" href="#wavelet-object" title="Permalink to this headline">¶</a></h2>
<dl class="class">
<dt id="pywt.Wavelet">
<em class="property">class </em><code class="descclassname">pywt.</code><code class="descname">Wavelet</code><span class="sig-paren">(</span><em>name</em><span class="optional">[</span>, <em>filter_bank=None</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#pywt.Wavelet" title="Permalink to this definition">¶</a></dt>
<dd><p>Describes properties of a wavelet identified by the specified wavelet <em>name</em>.
In order to use a built-in wavelet the <em>name</em> parameter must be a valid
wavelet name from the <a class="reference internal" href="#pywt.wavelist" title="pywt.wavelist"><code class="xref py py-func docutils literal"><span class="pre">pywt.wavelist()</span></code></a> list.</p>
<p>Custom Wavelet objects can be created by passing a user-defined filters set
with the <em>filter_bank</em> parameter.</p>
<table class="docutils field-list" frame="void" rules="none">
<col class="field-name" />
<col class="field-body" />
<tbody valign="top">
<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first last simple">
<li><strong>name</strong> – Wavelet name</li>
<li><strong>filter_bank</strong> – Use a user supplied filter bank instead of a built-in <a class="reference internal" href="#pywt.Wavelet" title="pywt.Wavelet"><code class="xref py py-class docutils literal"><span class="pre">Wavelet</span></code></a>.</li>
</ul>
</td>
</tr>
</tbody>
</table>
<p>The filter bank object can be a list of four filters coefficients or an object
with <a class="reference internal" href="#pywt.Wavelet.filter_bank" title="pywt.Wavelet.filter_bank"><code class="xref py py-attr docutils literal"><span class="pre">filter_bank</span></code></a> attribute, which returns a list of such
filters in the following order:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="p">[</span><span class="n">dec_lo</span><span class="p">,</span> <span class="n">dec_hi</span><span class="p">,</span> <span class="n">rec_lo</span><span class="p">,</span> <span class="n">rec_hi</span><span class="p">]</span>
</pre></div>
</div>
<p>Wavelet objects can also be used as a base filter banks. See section on
<a class="reference internal" href="#custom-wavelets"><span>using custom wavelets</span></a> for more information.</p>
<p><strong>Example:</strong></p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span>
<span class="gp">>>> </span><span class="n">wavelet</span> <span class="o">=</span> <span class="n">pywt</span><span class="o">.</span><span class="n">Wavelet</span><span class="p">(</span><span class="s">'db1'</span><span class="p">)</span>
</pre></div>
</div>
<dl class="attribute">
<dt id="pywt.Wavelet.name">
<code class="descname">name</code><a class="headerlink" href="#pywt.Wavelet.name" title="Permalink to this definition">¶</a></dt>
<dd><p>Wavelet name.</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.short_name">
<code class="descname">short_name</code><a class="headerlink" href="#pywt.Wavelet.short_name" title="Permalink to this definition">¶</a></dt>
<dd><p>Short wavelet name.</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.dec_lo">
<code class="descname">dec_lo</code><a class="headerlink" href="#pywt.Wavelet.dec_lo" title="Permalink to this definition">¶</a></dt>
<dd><p>Decomposition filter values.</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.dec_hi">
<code class="descname">dec_hi</code><a class="headerlink" href="#pywt.Wavelet.dec_hi" title="Permalink to this definition">¶</a></dt>
<dd><p>Decomposition filter values.</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.rec_lo">
<code class="descname">rec_lo</code><a class="headerlink" href="#pywt.Wavelet.rec_lo" title="Permalink to this definition">¶</a></dt>
<dd><p>Reconstruction filter values.</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.rec_hi">
<code class="descname">rec_hi</code><a class="headerlink" href="#pywt.Wavelet.rec_hi" title="Permalink to this definition">¶</a></dt>
<dd><p>Reconstruction filter values.</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.dec_len">
<code class="descname">dec_len</code><a class="headerlink" href="#pywt.Wavelet.dec_len" title="Permalink to this definition">¶</a></dt>
<dd><p>Decomposition filter length.</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.rec_len">
<code class="descname">rec_len</code><a class="headerlink" href="#pywt.Wavelet.rec_len" title="Permalink to this definition">¶</a></dt>
<dd><p>Reconstruction filter length.</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.filter_bank">
<code class="descname">filter_bank</code><a class="headerlink" href="#pywt.Wavelet.filter_bank" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns filters list for the current wavelet in the following order:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="p">[</span><span class="n">dec_lo</span><span class="p">,</span> <span class="n">dec_hi</span><span class="p">,</span> <span class="n">rec_lo</span><span class="p">,</span> <span class="n">rec_hi</span><span class="p">]</span>
</pre></div>
</div>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.inverse_filter_bank">
<code class="descname">inverse_filter_bank</code><a class="headerlink" href="#pywt.Wavelet.inverse_filter_bank" title="Permalink to this definition">¶</a></dt>
<dd><p>Returns list of reverse wavelet filters coefficients. The mapping from the
<cite>filter_coeffs</cite> list is as follows:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="p">[</span><span class="n">rec_lo</span><span class="p">[::</span><span class="o">-</span><span class="mi">1</span><span class="p">],</span> <span class="n">rec_hi</span><span class="p">[::</span><span class="o">-</span><span class="mi">1</span><span class="p">],</span> <span class="n">dec_lo</span><span class="p">[::</span><span class="o">-</span><span class="mi">1</span><span class="p">],</span> <span class="n">dec_hi</span><span class="p">[::</span><span class="o">-</span><span class="mi">1</span><span class="p">]]</span>
</pre></div>
</div>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.short_family_name">
<code class="descname">short_family_name</code><a class="headerlink" href="#pywt.Wavelet.short_family_name" title="Permalink to this definition">¶</a></dt>
<dd><p>Wavelet short family name</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.family_name">
<code class="descname">family_name</code><a class="headerlink" href="#pywt.Wavelet.family_name" title="Permalink to this definition">¶</a></dt>
<dd><p>Wavelet family name</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.orthogonal">
<code class="descname">orthogonal</code><a class="headerlink" href="#pywt.Wavelet.orthogonal" title="Permalink to this definition">¶</a></dt>
<dd><p>Set if wavelet is orthogonal</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.biorthogonal">
<code class="descname">biorthogonal</code><a class="headerlink" href="#pywt.Wavelet.biorthogonal" title="Permalink to this definition">¶</a></dt>
<dd><p>Set if wavelet is biorthogonal</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.symmetry">
<code class="descname">symmetry</code><a class="headerlink" href="#pywt.Wavelet.symmetry" title="Permalink to this definition">¶</a></dt>
<dd><p><code class="docutils literal"><span class="pre">asymmetric</span></code>, <code class="docutils literal"><span class="pre">near</span> <span class="pre">symmetric</span></code>, <code class="docutils literal"><span class="pre">symmetric</span></code></p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.vanishing_moments_psi">
<code class="descname">vanishing_moments_psi</code><a class="headerlink" href="#pywt.Wavelet.vanishing_moments_psi" title="Permalink to this definition">¶</a></dt>
<dd><p>Number of vanishing moments for the wavelet function</p>
</dd></dl>
<dl class="attribute">
<dt id="pywt.Wavelet.vanishing_moments_phi">
<code class="descname">vanishing_moments_phi</code><a class="headerlink" href="#pywt.Wavelet.vanishing_moments_phi" title="Permalink to this definition">¶</a></dt>
<dd><p>Number of vanishing moments for the scaling function</p>
</dd></dl>
<p><strong>Example:</strong></p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="k">def</span> <span class="nf">format_array</span><span class="p">(</span><span class="n">arr</span><span class="p">):</span>
<span class="gp">... </span> <span class="k">return</span> <span class="s">"[</span><span class="si">%s</span><span class="s">]"</span> <span class="o">%</span> <span class="s">", "</span><span class="o">.</span><span class="n">join</span><span class="p">([</span><span class="s">"</span><span class="si">%.14f</span><span class="s">"</span> <span class="o">%</span> <span class="n">x</span> <span class="k">for</span> <span class="n">x</span> <span class="ow">in</span> <span class="n">arr</span><span class="p">])</span>
<span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span>
<span class="gp">>>> </span><span class="n">wavelet</span> <span class="o">=</span> <span class="n">pywt</span><span class="o">.</span><span class="n">Wavelet</span><span class="p">(</span><span class="s">'db1'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="k">print</span> <span class="n">wavelet</span>
<span class="go">Wavelet db1</span>
<span class="go"> Family name: Daubechies</span>
<span class="go"> Short name: db</span>
<span class="go"> Filters length: 2</span>
<span class="go"> Orthogonal: True</span>
<span class="go"> Biorthogonal: True</span>
<span class="go"> Symmetry: asymmetric</span>
<span class="gp">>>> </span><span class="k">print</span> <span class="n">format_array</span><span class="p">(</span><span class="n">wavelet</span><span class="o">.</span><span class="n">dec_lo</span><span class="p">),</span> <span class="n">format_array</span><span class="p">(</span><span class="n">wavelet</span><span class="o">.</span><span class="n">dec_hi</span><span class="p">)</span>
<span class="go">[0.70710678118655, 0.70710678118655] [-0.70710678118655, 0.70710678118655]</span>
<span class="gp">>>> </span><span class="k">print</span> <span class="n">format_array</span><span class="p">(</span><span class="n">wavelet</span><span class="o">.</span><span class="n">rec_lo</span><span class="p">),</span> <span class="n">format_array</span><span class="p">(</span><span class="n">wavelet</span><span class="o">.</span><span class="n">rec_hi</span><span class="p">)</span>
<span class="go">[0.70710678118655, 0.70710678118655] [0.70710678118655, -0.70710678118655]</span>
</pre></div>
</div>
</dd></dl>
<div class="section" id="approximating-wavelet-and-scaling-functions-wavelet-wavefun">
<h3>Approximating wavelet and scaling functions - <code class="docutils literal"><span class="pre">Wavelet.wavefun()</span></code><a class="headerlink" href="#approximating-wavelet-and-scaling-functions-wavelet-wavefun" title="Permalink to this headline">¶</a></h3>
<dl class="method">
<dt id="pywt.Wavelet.wavefun">
<code class="descclassname">Wavelet.</code><code class="descname">wavefun</code><span class="sig-paren">(</span><em>level</em><span class="sig-paren">)</span><a class="headerlink" href="#pywt.Wavelet.wavefun" title="Permalink to this definition">¶</a></dt>
<dd><div class="versionchanged">
<p><span class="versionmodified">Changed in version 0.2: </span>The time (space) localisation of approximation function points was
added.</p>
</div>
<p>The <a class="reference internal" href="#pywt.Wavelet.wavefun" title="pywt.Wavelet.wavefun"><code class="xref py py-meth docutils literal"><span class="pre">wavefun()</span></code></a> method can be used to calculate approximations of
scaling function (<em>phi</em>) and wavelet function (<em>psi</em>) at the given level of
refinement.</p>
<p>For <a class="reference internal" href="#pywt.Wavelet.orthogonal" title="pywt.Wavelet.orthogonal"><code class="xref py py-attr docutils literal"><span class="pre">orthogonal</span></code></a> wavelets returns approximations of
scaling function and wavelet function with corresponding x-grid coordinates:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="p">[</span><span class="n">phi</span><span class="p">,</span> <span class="n">psi</span><span class="p">,</span> <span class="n">x</span><span class="p">]</span> <span class="o">=</span> <span class="n">wavelet</span><span class="o">.</span><span class="n">wavefun</span><span class="p">(</span><span class="n">level</span><span class="p">)</span>
</pre></div>
</div>
<p><strong>Example:</strong></p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span>
<span class="gp">>>> </span><span class="n">wavelet</span> <span class="o">=</span> <span class="n">pywt</span><span class="o">.</span><span class="n">Wavelet</span><span class="p">(</span><span class="s">'db2'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">phi</span><span class="p">,</span> <span class="n">psi</span><span class="p">,</span> <span class="n">x</span> <span class="o">=</span> <span class="n">wavelet</span><span class="o">.</span><span class="n">wavefun</span><span class="p">(</span><span class="n">level</span><span class="o">=</span><span class="mi">5</span><span class="p">)</span>
</pre></div>
</div>
<p>For other (<a class="reference internal" href="#pywt.Wavelet.biorthogonal" title="pywt.Wavelet.biorthogonal"><code class="xref py py-attr docutils literal"><span class="pre">biorthogonal</span></code></a> but not
<a class="reference internal" href="#pywt.Wavelet.orthogonal" title="pywt.Wavelet.orthogonal"><code class="xref py py-attr docutils literal"><span class="pre">orthogonal</span></code></a>) wavelets returns approximations of
scaling and wavelet function both for decomposition and reconstruction and
corresponding x-grid coordinates:</p>
<div class="highlight-python"><div class="highlight"><pre><span class="p">[</span><span class="n">phi_d</span><span class="p">,</span> <span class="n">psi_d</span><span class="p">,</span> <span class="n">phi_r</span><span class="p">,</span> <span class="n">psi_r</span><span class="p">,</span> <span class="n">x</span><span class="p">]</span> <span class="o">=</span> <span class="n">wavelet</span><span class="o">.</span><span class="n">wavefun</span><span class="p">(</span><span class="n">level</span><span class="p">)</span>
</pre></div>
</div>
<p><strong>Example:</strong></p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span>
<span class="gp">>>> </span><span class="n">wavelet</span> <span class="o">=</span> <span class="n">pywt</span><span class="o">.</span><span class="n">Wavelet</span><span class="p">(</span><span class="s">'bior3.5'</span><span class="p">)</span>
<span class="gp">>>> </span><span class="n">phi_d</span><span class="p">,</span> <span class="n">psi_d</span><span class="p">,</span> <span class="n">phi_r</span><span class="p">,</span> <span class="n">psi_r</span><span class="p">,</span> <span class="n">x</span> <span class="o">=</span> <span class="n">wavelet</span><span class="o">.</span><span class="n">wavefun</span><span class="p">(</span><span class="n">level</span><span class="o">=</span><span class="mi">5</span><span class="p">)</span>
</pre></div>
</div>
<div class="admonition seealso">
<p class="first admonition-title">See also</p>
<p class="last">You can find live examples of <a class="reference internal" href="#pywt.Wavelet.wavefun" title="pywt.Wavelet.wavefun"><code class="xref py py-meth docutils literal"><span class="pre">wavefun()</span></code></a> usage and
images of all the built-in wavelets on the
<a class="reference external" href="http://wavelets.pybytes.com">Wavelet Properties Browser</a> page.</p>
</div>
</dd></dl>
</div>
</div>
<div class="section" id="custom-wavelets">
<span id="using-custom-wavelets"></span><span id="id1"></span><h2>Using custom wavelets<a class="headerlink" href="#custom-wavelets" title="Permalink to this headline">¶</a></h2>
<p>PyWavelets comes with a <a class="reference internal" href="#pywt.wavelist" title="pywt.wavelist"><code class="xref py py-func docutils literal"><span class="pre">long</span> <span class="pre">list</span></code></a> of the most popular
wavelets built-in and ready to use. If you need to use a specific wavelet which
is not included in the list it is very easy to do so. Just pass a list of four
filters or an object with a <a class="reference internal" href="#pywt.Wavelet.filter_bank" title="pywt.Wavelet.filter_bank"><code class="xref py py-attr docutils literal"><span class="pre">filter_bank</span></code></a> attribute as a
<em>filter_bank</em> argument to the <a class="reference internal" href="#pywt.Wavelet" title="pywt.Wavelet"><code class="xref py py-class docutils literal"><span class="pre">Wavelet</span></code></a> constructor.</p>
<div class="compound">
<p class="compound-first">The filters list, either in a form of a simple Python list or returned via
the <a class="reference internal" href="#pywt.Wavelet.filter_bank" title="pywt.Wavelet.filter_bank"><code class="xref py py-attr docutils literal"><span class="pre">filter_bank</span></code></a> attribute, must be in the following order:</p>
<blockquote class="compound-middle">
<div><ul class="simple">
<li>lowpass decomposition filter</li>
<li>highpass decomposition filter</li>
<li>lowpass reconstruction filter</li>
<li>highpass reconstruction filter</li>
</ul>
</div></blockquote>
<p class="compound-last">just as for the <a class="reference internal" href="#pywt.Wavelet.filter_bank" title="pywt.Wavelet.filter_bank"><code class="xref py py-attr docutils literal"><span class="pre">filter_bank</span></code></a> attribute of the
<a class="reference internal" href="#pywt.Wavelet" title="pywt.Wavelet"><code class="xref py py-class docutils literal"><span class="pre">Wavelet</span></code></a> class.</p>
</div>
<p>The Wavelet object created in this way is a standard <a class="reference internal" href="#pywt.Wavelet" title="pywt.Wavelet"><code class="xref py py-class docutils literal"><span class="pre">Wavelet</span></code></a> instance.</p>
<p>The following example illustrates the way of creating custom Wavelet objects
from plain Python lists of filter coefficients and a <em>filter bank-like</em> objects.</p>
<blockquote>
<div><p><strong>Example:</strong></p>
<div class="highlight-python"><div class="highlight"><pre><span class="gp">>>> </span><span class="kn">import</span> <span class="nn">pywt</span><span class="o">,</span> <span class="nn">math</span>
<span class="gp">>>> </span><span class="n">c</span> <span class="o">=</span> <span class="n">math</span><span class="o">.</span><span class="n">sqrt</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span><span class="o">/</span><span class="mi">2</span>
<span class="gp">>>> </span><span class="n">dec_lo</span><span class="p">,</span> <span class="n">dec_hi</span><span class="p">,</span> <span class="n">rec_lo</span><span class="p">,</span> <span class="n">rec_hi</span> <span class="o">=</span> <span class="p">[</span><span class="n">c</span><span class="p">,</span> <span class="n">c</span><span class="p">],</span> <span class="p">[</span><span class="o">-</span><span class="n">c</span><span class="p">,</span> <span class="n">c</span><span class="p">],</span> <span class="p">[</span><span class="n">c</span><span class="p">,</span> <span class="n">c</span><span class="p">],</span> <span class="p">[</span><span class="n">c</span><span class="p">,</span> <span class="o">-</span><span class="n">c</span><span class="p">]</span>
<span class="gp">>>> </span><span class="n">filter_bank</span> <span class="o">=</span> <span class="p">[</span><span class="n">dec_lo</span><span class="p">,</span> <span class="n">dec_hi</span><span class="p">,</span> <span class="n">rec_lo</span><span class="p">,</span> <span class="n">rec_hi</span><span class="p">]</span>
<span class="gp">>>> </span><span class="n">myWavelet</span> <span class="o">=</span> <span class="n">pywt</span><span class="o">.</span><span class="n">Wavelet</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s">"myHaarWavelet"</span><span class="p">,</span> <span class="n">filter_bank</span><span class="o">=</span><span class="n">filter_bank</span><span class="p">)</span>
<span class="go">>>></span>
<span class="gp">>>> </span><span class="k">class</span> <span class="nc">HaarFilterBank</span><span class="p">(</span><span class="nb">object</span><span class="p">):</span>
<span class="gp">... </span> <span class="nd">@property</span>
<span class="gp">... </span> <span class="k">def</span> <span class="nf">filter_bank</span><span class="p">(</span><span class="bp">self</span><span class="p">):</span>
<span class="gp">... </span> <span class="n">c</span> <span class="o">=</span> <span class="n">math</span><span class="o">.</span><span class="n">sqrt</span><span class="p">(</span><span class="mi">2</span><span class="p">)</span><span class="o">/</span><span class="mi">2</span>
<span class="gp">... </span> <span class="n">dec_lo</span><span class="p">,</span> <span class="n">dec_hi</span><span class="p">,</span> <span class="n">rec_lo</span><span class="p">,</span> <span class="n">rec_hi</span> <span class="o">=</span> <span class="p">[</span><span class="n">c</span><span class="p">,</span> <span class="n">c</span><span class="p">],</span> <span class="p">[</span><span class="o">-</span><span class="n">c</span><span class="p">,</span> <span class="n">c</span><span class="p">],</span> <span class="p">[</span><span class="n">c</span><span class="p">,</span> <span class="n">c</span><span class="p">],</span> <span class="p">[</span><span class="n">c</span><span class="p">,</span> <span class="o">-</span><span class="n">c</span><span class="p">]</span>
<span class="gp">... </span> <span class="k">return</span> <span class="p">[</span><span class="n">dec_lo</span><span class="p">,</span> <span class="n">dec_hi</span><span class="p">,</span> <span class="n">rec_lo</span><span class="p">,</span> <span class="n">rec_hi</span><span class="p">]</span>
<span class="gp">>>> </span><span class="n">filter_bank</span> <span class="o">=</span> <span class="n">HaarFilterBank</span><span class="p">()</span>
<span class="gp">>>> </span><span class="n">myOtherWavelet</span> <span class="o">=</span> <span class="n">pywt</span><span class="o">.</span><span class="n">Wavelet</span><span class="p">(</span><span class="n">name</span><span class="o">=</span><span class="s">"myHaarWavelet"</span><span class="p">,</span> <span class="n">filter_bank</span><span class="o">=</span><span class="n">filter_bank</span><span class="p">)</span>
</pre></div>
</div>
</div></blockquote>
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