<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html > <head><title>Preconditioner data structure</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <meta name="generator" content="TeX4ht (https://tug.org/tex4ht/)"> <meta name="originator" content="TeX4ht (https://tug.org/tex4ht/)"> <!-- html,3 --> <meta name="src" content="userhtml.tex"> <link rel="stylesheet" type="text/css" href="userhtml.css"> </head><body > <!--l. 1313--><div class="crosslinks"><p class="noindent">[<a href="userhtmlsu11.html" >next</a>] [<a href="userhtmlsu7.html" >prev</a>] [<a href="userhtmlsu7.html#tailuserhtmlsu7.html" >prev-tail</a>] [<a href="userhtmlsu5.html#tailuserhtmlsu8.html">tail</a>] [<a href="userhtmlsu7.html#userhtmlsu10.html" >up</a>] </p></div> <h4 class="subsectionHead"><span class="titlemark">3.4 </span> <a id="x16-530003.4"></a>Preconditioner data structure</h4> <!--l. 1315--><p class="noindent" >Our base library offers support for simple well known preconditioners like Diagonal Scaling or Block Jacobi with incomplete factorization ILU(0). <!--l. 1319--><p class="indent" > A preconditioner is held in the <a id="precdata"></a><span class="cmtt-10">psb</span><span class="cmtt-10">_prec</span><span class="cmtt-10">_type </span>data structure reported in figure <a href="#x16-53001r4">4<!--tex4ht:ref: fig:prectype --></a>. The <span class="lstinline"></span><span class="cmtt-10">psb_prec_type</span> data type may contain a simple preconditioning matrix with the associated communication descriptor.The internal preconditioner is allocated appropriately with the dynamic type corresponding to the desired preconditioner. <!--l. 1337--><p class="indent" > <a id="x16-53001r4"></a><hr class="float"><div class="float" > <div class="center" > <!--l. 1347--><p class="noindent" > <div class="minipage"><pre class="verbatim" id="verbatim-30">   type psb_Tprec_type     class(psb_T_base_prec_type), allocatable :: prec   end type psb_Tprec_type </pre> <!--l. 1355--><p class="nopar" ></div></div> <br /> <div class="caption" ><span class="id">Listing 4: </span><span class="content">The PSBLAS defined data type that contains a preconditioner.</span></div><!--tex4ht:label?: x16-53001r4 --> </div><hr class="endfloat" /> <!--l. 1389--><div class="crosslinks"><p class="noindent">[<a href="userhtmlsu11.html" >next</a>] [<a href="userhtmlsu7.html" >prev</a>] [<a href="userhtmlsu7.html#tailuserhtmlsu7.html" >prev-tail</a>] [<a href="userhtmlsu8.html" >front</a>] [<a href="userhtmlsu7.html#userhtmlsu10.html" >up</a>] </p></div> <!--l. 1389--><p class="indent" > <a id="tailuserhtmlsu8.html"></a> </body></html>