<?xml version="1.0" encoding="ISO-8859-1"?><refentry xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:svg="http://www.w3.org/2000/svg" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:db="http://docbook.org/ns/docbook" version="5.0-subset Scilab" xml:lang="en" xml:id="pl_lft_direct_d"><info><pubdate>04-Apr-2006</pubdate></info><refnamediv><refname>pl_lft_direct_d</refname><refpurpose>[For comparison only] Legendre-Fenchel conjugate, direct computation on {1,...,n}</refpurpose></refnamediv>
  
   
  
   
  
   
  
   
  
   

  
   <refsynopsisdiv><title>Calling Sequence</title><synopsis>Conj = pl_lft_direct_d(Y)</synopsis></refsynopsisdiv>

  
   <refsection><title>Parameters</title>
  
      <variablelist>

    
         <varlistentry>
    
            <term>Y</term>
    
            <listitem>
       
               <para>column vector. The value of the function on the grid {1,...,n}: usually Y(i)=f(i) for some function f, with 1 &lt;= i &lt;= n and n=length(Y).
       </para>
    
            </listitem>
    
         </varlistentry>

    
         <varlistentry>
    
            <term>Conj</term>
    
            <listitem>
       
               <para>column vector. Contains the value of the conjugate f* of the function f evaluated at the points j. In other words: Conj(j) = Max(j * i - Y(i) | over all indexes i).
       </para>
    
            </listitem>
    
         </varlistentry>
  
      </variablelist>
  
   </refsection>
 
  
   <refsection><title>Description</title>
     
         <para>
         Warning: This function is provided only for comparison purposes and unit testing, use the more efficient <link linkend="pl_lft_llt_d">pl_lft_llt_d</link> for faster computation.
       </para>
     
         <para>
	     Wrap over for easier computation of distance transforms. The function calls pl_lft_direct(X,Y,S) with n=length(Y), X=(1:1:n)' and S=X. See <link linkend="pl_lft_direct">pl_lft_direct</link> for more information.
     </para>
  
   </refsection>

  
   <refsection><title>Examples</title><programlisting role="example"><![CDATA[
        row = [1 2.5 5 8.5 13]';
        conj_part = -1.*pl_lft_direct_d(row);
        b = isequal(conj_part, [0 -1.5 -4 -7.5 -12]');
  ]]></programlisting></refsection>

  
   <refsection><title>See Also</title><simplelist type="inline">
    
      <member> 
         <link linkend="pl_lft_direct">pl_lft_direct</link> 
      </member>
    
      <member> 
         <link linkend="pl_lft_llt_d">pl_lft_llt_d</link> 
      </member>    
  
   </simplelist></refsection>

  
   <refsection><title>Authors</title><para>
	  
      <literal>Yves Lucet</literal>, University of British Columbia, BC, Canada
  </para></refsection>
  
   <refsection><title>Used Functions</title>
	  
      <para>
		  
         <link linkend="pl_lft_direct">pl_lft_direct</link>
	  
      </para>
  
   </refsection>   

</refentry>
