<?xml version="1.0" encoding="utf-8" standalone="no"?>
<!DOCTYPE document PUBLIC "-//CNX//DTD CNXML 0.5 plus MathML//EN" "http://cnx.rice.edu/cnxml/0.5/DTD/cnxml_mathml.dtd">
<document xmlns="http://cnx.rice.edu/cnxml" xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="new2">
  <name xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Values of g[n] and h[n] for the Haar System</name>
  <metadata xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">
  <md:version xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">2.1</md:version>
  <md:created xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">2003/01/17</md:created>
  <md:revised xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">2005/06/10 11:00:28 GMT-5</md:revised>
  <md:authorlist xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">
      <md:author xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="schniter">
      <md:firstname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Phil</md:firstname>
      
      <md:surname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Schniter</md:surname>
      <md:email xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">schniter@ee.eng.ohio-state.edu</md:email>
    </md:author>
  </md:authorlist>

  <md:maintainerlist xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">
    <md:maintainer xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="charlet">
      <md:firstname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Charlet</md:firstname>
      
      <md:surname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Reedstrom</md:surname>
      <md:email xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">charlet@rice.edu</md:email>
    </md:maintainer>
    <md:maintainer xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="schniter">
      <md:firstname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Phil</md:firstname>
      
      <md:surname xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Schniter</md:surname>
      <md:email xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">schniter@ee.eng.ohio-state.edu</md:email>
    </md:maintainer>
  </md:maintainerlist>
  
  <md:keywordlist xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">
    <md:keyword xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">Haar</md:keyword>
    <md:keyword xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">scaling equation</md:keyword>
  </md:keywordlist>

  <md:abstract xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/"/>
</metadata>


  <content xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/">
      <para xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="p11">
	The coefficients
	<m:math>
	  <m:set>
	    <m:apply>
	      <m:ci type="fn" class="discrete">h</m:ci>
	      <m:ci>n</m:ci>
	    </m:apply>
	  </m:set>
	</m:math> were originally introduced at describe
	<m:math>
	  <m:apply>
	    <m:ci type="fn"><m:msub>
		<m:mi>φ</m:mi>
		<m:mrow>
		  <m:mn>1</m:mn>
		  <m:mo>,</m:mo>
		  <m:mn>0</m:mn>
		</m:mrow>
	      </m:msub></m:ci>
	    <m:ci>t</m:ci>
	  </m:apply>
	</m:math> in terms of the basis for
	<m:math>
	  <m:ci><m:msub>
	      <m:mi>V</m:mi>
	      <m:mn>0</m:mn>
	    </m:msub></m:ci>
	</m:math>:

	<m:math display="block">
	  <m:apply>
	    <m:eq/>
	    <m:apply>
	      <m:ci type="fn"><m:msub>
		  <m:mi>φ</m:mi>
		  <m:mrow>
		    <m:mn>1</m:mn>
		    <m:mo>,</m:mo>
		    <m:mn>0</m:mn>
		  </m:mrow>
		</m:msub></m:ci>
	      <m:ci>t</m:ci>
	    </m:apply>
	    <m:apply>
	      <m:sum/>
	      <m:domainofapplication>
		<m:ci>n</m:ci>
	      </m:domainofapplication>
	      <m:apply>
		<m:times/>
		<m:apply>
		  <m:ci type="fn" class="discrete">h</m:ci>
		  <m:ci>n</m:ci>
		</m:apply>
		<m:apply>
		  <m:ci type="fn"><m:msub>
		      <m:mi>φ</m:mi>
		      <m:mrow>
			<m:mn>0</m:mn>
			<m:mo>,</m:mo>
			<m:mi>n</m:mi>
		      </m:mrow>
		    </m:msub></m:ci>
		  <m:ci>t</m:ci>
		</m:apply>
	      </m:apply>
	    </m:apply>
	  </m:apply>
	  <m:mtext>.</m:mtext>
	</m:math>
	From the previous equation we find that

	<equation xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="eqn18">
	  <m:math>
	    <m:apply>
	      <m:eq/>
	      <m:apply>
		<m:scalarproduct/>
		<m:apply>
		  <m:ci type="fn"><m:msub>
		      <m:mi>φ</m:mi>
		      <m:mrow>
			<m:mn>0</m:mn>
			<m:mo>,</m:mo>
			<m:mi>m</m:mi>
		      </m:mrow>
		    </m:msub></m:ci>
		  <m:ci>t</m:ci>
		</m:apply>
		<m:apply>
		  <m:ci type="fn"><m:msub>
		      <m:mi>φ</m:mi>
		      <m:mrow>
			<m:mn>1</m:mn>
			<m:mo>,</m:mo>
			<m:mn>0</m:mn>
		      </m:mrow>
		    </m:msub></m:ci>
		  <m:ci>t</m:ci>
		</m:apply>
	      </m:apply>

	      <m:apply>
		<m:scalarproduct/>
		<m:apply>
		  <m:ci type="fn"><m:msub>
		      <m:mi>φ</m:mi>
		      <m:mrow>
			<m:mn>0</m:mn>
			<m:mo>,</m:mo>
			<m:mi>m</m:mi>
		      </m:mrow>
		    </m:msub></m:ci>
		  <m:ci>t</m:ci>
		</m:apply>
		<m:apply>
		  <m:sum/>
		  <m:domainofapplication>
		    <m:ci>n</m:ci>
		  </m:domainofapplication>
		  <m:apply>
		    <m:times/>
		    <m:apply>
		      <m:ci type="fn" class="discrete">h</m:ci>
		      <m:ci>n</m:ci>
		    </m:apply>
		    <m:apply>
		      <m:ci type="fn"><m:msub>
			  <m:mi>φ</m:mi>
			  <m:mrow>
			    <m:mn>0</m:mn>
			    <m:mo>,</m:mo>
			    <m:mi>n</m:mi>
			  </m:mrow>
			</m:msub></m:ci>
		      <m:ci>t</m:ci>
		    </m:apply>
		  </m:apply>
		</m:apply>
	      </m:apply>

	      <m:apply>
		<m:sum/>
		<m:domainofapplication>
		  <m:ci>n</m:ci>
		</m:domainofapplication>
		<m:apply>
		  <m:times/>
		  <m:apply>
		    <m:ci type="fn" class="discrete">h</m:ci>
		    <m:ci>n</m:ci>
		  </m:apply>
		  <m:apply>
		    <m:scalarproduct/>
		    <m:apply>
		      <m:ci type="fn"><m:msub>
			  <m:mi>φ</m:mi>
			  <m:mrow>
			    <m:mn>0</m:mn>
			    <m:mo>,</m:mo>
			    <m:mi>m</m:mi>
			  </m:mrow>
			</m:msub></m:ci>
		      <m:ci>t</m:ci>
		    </m:apply>
		    <m:apply>
		      <m:ci type="fn"><m:msub>
			  <m:mi>φ</m:mi>
			  <m:mrow>
			    <m:mn>0</m:mn>
			    <m:mo>,</m:mo>
			    <m:mi>n</m:mi>
			  </m:mrow>
			</m:msub></m:ci>
		      <m:ci>t</m:ci>
		    </m:apply>
		  </m:apply>
		</m:apply>
	      </m:apply>
	      <m:apply>
		<m:ci type="fn" class="discrete">h</m:ci>
		<m:ci>m</m:ci>
	      </m:apply>
	    </m:apply>
	  </m:math>
	</equation>
	where 
	<m:math>
	  <m:apply>
	    <m:eq/>
	    <m:apply>
	      <m:ci type="fn" class="discrete">δ</m:ci>
	      <m:apply>
		<m:minus/>
		<m:ci>n</m:ci>
		<m:ci>m</m:ci>
	      </m:apply>
	    </m:apply>
	    <m:apply>
	      <m:scalarproduct/>
	      <m:apply>
		<m:ci type="fn"><m:msub>
		    <m:mi>φ</m:mi>
		    <m:mrow>
		      <m:mn>0</m:mn>
		      <m:mo>,</m:mo>
		      <m:mi>m</m:mi>
		    </m:mrow>
		  </m:msub></m:ci>
		<m:ci>t</m:ci>
	      </m:apply>
	      <m:apply>
		<m:ci type="fn"><m:msub>
		    <m:mi>φ</m:mi>
		    <m:mrow>
		      <m:mn>0</m:mn>
		      <m:mo>,</m:mo>
		      <m:mi>n</m:mi>
		    </m:mrow>
		  </m:msub></m:ci>
		<m:ci>t</m:ci>
	      </m:apply>
	    </m:apply>
	  </m:apply>
	</m:math>, which gives a way to calculate the coefficients
	<m:math>
	  <m:set>
	    <m:apply>
	      <m:ci type="fn" class="discrete">h</m:ci>
	      <m:ci>m</m:ci>
	    </m:apply>
	  </m:set>
	</m:math> when we know 
	<m:math>
	  <m:apply>
	    <m:ci type="fn"><m:msub>
		<m:mi>φ</m:mi>
		<m:mrow>
		  <m:mi>k</m:mi>
		  <m:mo>,</m:mo>
		  <m:mi>n</m:mi>
		</m:mrow>
	      </m:msub></m:ci>
	    <m:ci>t</m:ci>
	  </m:apply>
	</m:math>.
      </para>

      <para xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="p12">
	In the Haar case
	<equation xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="eqn19">
	  <m:math>
	    <m:apply>
	      <m:eq/>
	      <m:apply>
		<m:ci type="fn" class="discrete">h</m:ci>
		<m:ci>m</m:ci>
	      </m:apply>
	      <m:apply>
		<m:int/>
		<m:bvar><m:ci>t</m:ci></m:bvar>
		<m:lowlimit>
		  <m:apply>
		    <m:minus/>
		    <m:infinity/>
		  </m:apply>
		</m:lowlimit>
		<m:uplimit>
		  <m:infinity/>
		</m:uplimit>
		<m:apply>
		  <m:times/>
		  <m:apply>
		    <m:ci type="fn"><m:msub>
			<m:mi>φ</m:mi>
			<m:mrow>
			  <m:mn>0</m:mn>
			  <m:mo>,</m:mo>
			  <m:mi>m</m:mi>
			</m:mrow>
		      </m:msub></m:ci>
		    <m:ci>t</m:ci>
		  </m:apply>
		  <m:apply>
		    <m:ci type="fn"><m:msub>
			<m:mi>φ</m:mi>
			<m:mrow>
			  <m:mn>1</m:mn>
			  <m:mo>,</m:mo>
			  <m:mn>0</m:mn>
			</m:mrow>
		      </m:msub></m:ci>
		    <m:ci>t</m:ci>
		  </m:apply>
		</m:apply>
	      </m:apply>

	      <m:apply>
		<m:int/>
		<m:bvar><m:ci>t</m:ci></m:bvar>
		<m:lowlimit><m:ci>m</m:ci></m:lowlimit>
		<m:uplimit>
		  <m:apply>
		    <m:plus/>
		    <m:ci>m</m:ci>
		    <m:cn>1</m:cn>
		  </m:apply>
		</m:uplimit>
		<m:apply>
		  <m:ci type="fn"><m:msub>
		      <m:mi>φ</m:mi>
		      <m:mrow>
			<m:mn>1</m:mn>
			<m:mo>,</m:mo>
			<m:mn>0</m:mn>
		      </m:mrow>
		    </m:msub></m:ci>
		  <m:ci>t</m:ci>
		</m:apply>
	      </m:apply>

	      <m:piecewise>
		<m:piece>
		  <m:apply>
		    <m:divide/>
		    <m:cn>1</m:cn>
		    <m:apply>
		      <m:root/>
		      <m:cn>2</m:cn>
		    </m:apply>
		  </m:apply>
		  <m:apply>
		    <m:in/>
		    <m:ci>m</m:ci>
		    <m:set>
		      <m:cn>0</m:cn>
		      <m:cn>1</m:cn>
		    </m:set>
		  </m:apply>
		</m:piece>
		<m:otherwise>
		  <m:cn>0</m:cn>
		</m:otherwise>
	      </m:piecewise>
	    </m:apply>
	  </m:math>
	</equation>
	since 
	<m:math>
	  <m:apply>
	    <m:eq/>
	    <m:apply>
	      <m:ci type="fn"><m:msub>
		  <m:mi>φ</m:mi>
		  <m:mrow>
		    <m:mn>1</m:mn>
		    <m:mo>,</m:mo>
		    <m:mn>0</m:mn>
		  </m:mrow>
		</m:msub></m:ci>
	      <m:ci>t</m:ci>
	    </m:apply>
	    <m:apply>
	      <m:divide/>
	      <m:cn>1</m:cn>
	      <m:apply>
		<m:root/>
		<m:cn>2</m:cn>
	      </m:apply>
	    </m:apply>
	  </m:apply>
	</m:math> in the interval
	<m:math>
	  <m:interval closure="closed-open">
	    <m:cn>0</m:cn>
	    <m:cn>2</m:cn>
	  </m:interval>
	</m:math> and zero otherwise.  Then choosing 
	<m:math>
	  <m:apply>
	    <m:eq/>
	    <m:ci>P</m:ci>
	    <m:cn>1</m:cn>
	  </m:apply>
	</m:math> in 
	<m:math>
	  <m:apply>
	    <m:eq/>
	    <m:apply>
	      <m:ci type="fn" class="discrete">g</m:ci>
	      <m:ci>n</m:ci>
	    </m:apply>
	    <m:apply>
	      <m:times/>
	      <m:apply>
		<m:power/>
		<m:cn>-1</m:cn>
		<m:ci>n</m:ci>
	      </m:apply>
	      <m:apply>
		<m:ci type="fn">h</m:ci>
		<m:apply>
		  <m:minus/>
		  <m:ci>P</m:ci>
		  <m:ci>n</m:ci>
		</m:apply>
	      </m:apply>
	    </m:apply>
	  </m:apply>
	</m:math>, we find that
	
	<m:math display="block">
	  <m:apply>
	    <m:eq/>
	    <m:apply>
	      <m:ci type="fn" class="discrete">g</m:ci>
	      <m:ci>n</m:ci>
	    </m:apply>
	    <m:piecewise>
	      <m:piece>
		<m:apply>
		  <m:divide/>
		  <m:cn>1</m:cn>
		  <m:apply>
		    <m:root/>
		    <m:cn>2</m:cn>
		  </m:apply>
		</m:apply>
		<m:cn>0</m:cn>
	      </m:piece>

	      <m:piece>
		<m:apply>
		  <m:minus/>
		  <m:apply>
		    <m:divide/>
		    <m:cn>1</m:cn>
		    <m:apply>
		      <m:root/>
		      <m:cn>2</m:cn>
		    </m:apply>
		  </m:apply>
		</m:apply>
		<m:cn>1</m:cn>
	      </m:piece>

	      <m:otherwise>
		<m:cn>0</m:cn>
	      </m:otherwise>
	    </m:piecewise>
	  </m:apply>
	</m:math>
	for the Haar system.  From the wavelet scaling equation

	<m:math display="block">
	  <m:apply>
	    <m:eq/>
	    <m:apply>
	      <m:ci type="fn">ψ</m:ci>
	      <m:ci>t</m:ci>
	    </m:apply>
	    <m:apply>
	      <m:times/>
	      <m:apply>
		<m:root/>
		<m:cn>2</m:cn>
	      </m:apply>
	      <m:apply>
		<m:sum/>
		<m:domainofapplication>
		  <m:ci>n</m:ci>
		</m:domainofapplication>
		<m:apply>
		  <m:times/>
		  <m:apply>
		    <m:ci type="fn" class="discrete">g</m:ci>
		    <m:ci>n</m:ci>
		  </m:apply>
		  <m:apply>
		    <m:ci type="fn">φ</m:ci>
		    <m:apply>
		      <m:minus/>
		      <m:apply>
			<m:times/>
			<m:cn>2</m:cn>
			<m:ci>t</m:ci>
		      </m:apply>
		      <m:ci>n</m:ci>
		    </m:apply>
		  </m:apply>
		</m:apply>
	      </m:apply>
	    </m:apply>

		
	    <m:apply>
	      <m:minus/>
	      <m:apply>
		<m:ci type="fn">φ</m:ci>
		<m:apply>
		  <m:times/>
		  <m:cn>2</m:cn>
		  <m:ci>t</m:ci>
		</m:apply>
	      </m:apply>
	      <m:apply>
		<m:ci type="fn">φ</m:ci>
		<m:apply>
		  <m:minus/>
		  <m:apply>
		    <m:times/>
		    <m:cn>2</m:cn>
		    <m:ci>t</m:ci>
		  </m:apply>
		  <m:cn>1</m:cn>
		</m:apply>
	      </m:apply>
	    </m:apply>
	  </m:apply>
	</m:math>
	we can see that the Haar mother wavelet and scaling function
	look like in <cnxn xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" target="fig2" strength="9"/>:
      </para>

      <figure xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="fig2">
	<media xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" type="image/png" src="haar_wavelet.png"/>
      </figure>

      <para xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="p13">
	It is now easy to see, in the Haar case, how integer shifts of
	the mother wavelet describe the differences between signals in
	<m:math>
	  <m:ci><m:msub>
	      <m:mi>V</m:mi>
	      <m:mrow>
		<m:mo>−</m:mo>
		<m:mn>1</m:mn>
	      </m:mrow>
	    </m:msub></m:ci>
	</m:math> and 
	<m:math>
	  <m:ci><m:msub>
	      <m:mi>V</m:mi>
	      <m:mn>0</m:mn>
	    </m:msub></m:ci>
	</m:math> (<cnxn xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" target="fig3" strength="9"/>):
      </para>

      <figure xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="fig3">
	<media xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" type="image/png" src="haar_shifts.png"/>
      </figure>

      <para xmlns:md="http://cnx.rice.edu/mdml/0.4" xmlns:m="http://www.w3.org/1998/Math/MathML" xmlns:bib="http://bibtexml.sf.net/" id="p14">
	We expect this because
	<m:math>
	  <m:apply>
	    <m:eq/>
	    <m:ci><m:msub>
		<m:mi>V</m:mi>
		<m:mrow>
		  <m:mo>−</m:mo>
		  <m:mn>1</m:mn>
		</m:mrow>
	      </m:msub></m:ci>
	    <m:apply>
	      <m:xor/>
	      <m:ci><m:msub>
		  <m:mi>V</m:mi>
		  <m:mn>0</m:mn>
		</m:msub></m:ci>
	      <m:ci><m:msub>
		  <m:mi>W</m:mi>
		  <m:mn>0</m:mn>
		</m:msub></m:ci>
	    </m:apply>
	  </m:apply>
	</m:math>.
      </para>

  </content>
</document>
