<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html > <head><title>Auxiliary Methods</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. 900--><div class="crosslinks"><p class="noindent"><span class="cmr-12">[</span><a href="userhtmlsu15.html" ><span class="cmr-12">prev</span></a><span class="cmr-12">] [</span><a href="userhtmlsu15.html#tailuserhtmlsu15.html" ><span class="cmr-12">prev-tail</span></a><span class="cmr-12">] [</span><a href="#tailuserhtmlsu16.html"><span class="cmr-12">tail</span></a><span class="cmr-12">] [</span><a href="userhtmlse5.html#userhtmlsu16.html" ><span class="cmr-12">up</span></a><span class="cmr-12">] </span></p></div> <h4 class="subsectionHead"><span class="titlemark"><span class="cmr-12">5.9 </span></span> <a id="x26-250005.9"></a><span class="cmr-12">Auxiliary Methods</span></h4> <!--l. 901--><p class="noindent" ><span class="cmr-12">Various functionalities are implemented as additional methods of the preconditioner</span> <span class="cmr-12">object.</span> <!--l. 904--><p class="noindent" > <h5 class="subsubsectionHead"><span class="titlemark"><span class="cmr-12">5.9.1 </span></span> <a id="x26-260005.9.1"></a><span class="cmr-12">Method: dump</span></h5> <div class="center" > <!--l. 906--><p class="noindent" > <!--l. 907--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">call</span><span class="cmtt-12"> </span><span class="cmtt-12">p</span><span class="cmtt-12">%</span><span class="cmtt-12">dump</span><span class="cmtt-12">(</span><span class="cmtt-12">info</span><span class="cmtt-12">[,</span><span class="cmtt-12">istart</span><span class="cmtt-12">,</span><span class="cmtt-12">iend</span><span class="cmtt-12">,</span><span class="cmtt-12">prefix</span><span class="cmtt-12">,</span><span class="cmtt-12">head</span><span class="cmtt-12">,</span><span class="cmtt-12">ac</span><span class="cmtt-12">,</span><span class="cmtt-12">rp</span><span class="cmtt-12">,</span><span class="cmtt-12">smoother</span><span class="cmtt-12">,</span><span class="cmtt-12">solver</span><span class="cmtt-12">,</span><span class="cmtt-12">global_num</span><span class="cmtt-12">])</span><br /> </div> <!--l. 910--><p class="noindent" ><span class="cmr-12">Dump on file.</span> <!--l. 913--><p class="noindent" ><span class="cmbx-12">Arguments</span> <div class="tabular"> <table id="TBL-17" class="tabular" cellspacing="0" cellpadding="0" ><colgroup id="TBL-17-1g"><col id="TBL-17-1"><col id="TBL-17-2"></colgroup><tr style="vertical-align:baseline;" id="TBL-17-1-"><td style="white-space:normal; text-align:left;" id="TBL-17-1-1" class="td11"><!--l. 916--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">info</span> </td><td style="white-space:normal; text-align:left;" id="TBL-17-1-2" class="td11"><!--l. 916--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">integer</span><span class="cmtt-12">,</span><span class="cmtt-12"> </span><span class="cmtt-12">intent</span><span class="cmtt-12">(</span><span class="cmtt-12">out</span><span class="cmtt-12">)</span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-17-2-"><td style="white-space:normal; text-align:left;" id="TBL-17-2-1" class="td11"><!--l. 917--><p class="noindent" > </td><td style="white-space:normal; text-align:left;" id="TBL-17-2-2" class="td11"><!--l. 917--><p class="noindent" ><span class="cmr-12">Error code. If no error, 0 is returned. See Section</span><span class="cmr-12"> </span><a href="userhtmlse7.html#x28-320007"><span class="cmr-12">7</span><!--tex4ht:ref: sec:errors --></a> <span class="cmr-12">for details.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-17-3-"><td style="white-space:normal; text-align:left;" id="TBL-17-3-1" class="td11"><!--l. 918--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">amold</span> </td><td style="white-space:normal; text-align:left;" id="TBL-17-3-2" class="td11"><!--l. 918--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">class</span><span class="cmtt-12">(</span><span class="cmtt-12">psb_</span><span class="cmti-12">x</span><span class="lstinline"></span><span class="cmtt-12">_base_sparse_mat</span><span class="cmtt-12">),</span><span class="cmtt-12"> </span><span class="cmtt-12">intent</span><span class="cmtt-12">(</span><span class="cmtt-12">in</span><span class="cmtt-12">),</span><span class="cmtt-12"> </span><span class="cmtt-12">optional</span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-17-4-"><td style="white-space:normal; text-align:left;" id="TBL-17-4-1" class="td11"><!--l. 919--><p class="noindent" > </td><td style="white-space:normal; text-align:left;" id="TBL-17-4-2" class="td11"><!--l. 919--><p class="noindent" ><span class="cmr-12">The desired dynamic type for internal matrix components; this</span> <span class="cmr-12">allows e.g. running on GPUs; it needs not be the same on all</span> <span class="cmr-12">processes. See the PSBLAS User’s Guide for details </span><span class="cite"><span class="cmr-12">[</span><a href="userhtmlli5.html#XPSBLASGUIDE"><span class="cmr-12">20</span></a><span class="cmr-12">]</span></span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-17-5-"><td style="white-space:normal; text-align:left;" id="TBL-17-5-1" class="td11"> </td> </tr></table></div> <!--l. 926--><p class="noindent" > <h5 class="subsubsectionHead"><span class="titlemark"><span class="cmr-12">5.9.2 </span></span> <a id="x26-270005.9.2"></a><span class="cmr-12">Method: clone</span></h5> <div class="center" > <!--l. 928--><p class="noindent" > <!--l. 929--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">call</span><span class="cmtt-12"> </span><span class="cmtt-12">p</span><span class="cmtt-12">%</span><span class="cmtt-12">clone</span><span class="cmtt-12">(</span><span class="cmtt-12">pout</span><span class="cmtt-12">,</span><span class="cmtt-12">info</span><span class="cmtt-12">)</span><br /> </div> <!--l. 932--><p class="noindent" ><span class="cmr-12">Create a (deep) copy of the preconditioner object.</span> <!--l. 935--><p class="noindent" ><span class="cmbx-12">Arguments</span> <div class="tabular"> <table id="TBL-18" class="tabular" cellspacing="0" cellpadding="0" ><colgroup id="TBL-18-1g"><col id="TBL-18-1"><col id="TBL-18-2"></colgroup><tr style="vertical-align:baseline;" id="TBL-18-1-"><td style="white-space:normal; text-align:left;" id="TBL-18-1-1" class="td11"><!--l. 938--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">pout</span> </td><td style="white-space:normal; text-align:left;" id="TBL-18-1-2" class="td11"><!--l. 938--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">type</span><span class="cmtt-12">(</span><span class="cmtt-12">amg_</span><span class="cmti-12">x</span><span class="lstinline"></span><span class="cmtt-12">prec_type</span><span class="cmtt-12">),</span><span class="cmtt-12"> </span><span class="cmtt-12">intent</span><span class="cmtt-12">(</span><span class="cmtt-12">out</span><span class="cmtt-12">)</span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-18-2-"><td style="white-space:normal; text-align:left;" id="TBL-18-2-1" class="td11"><!--l. 939--><p class="noindent" > </td><td style="white-space:normal; text-align:left;" id="TBL-18-2-2" class="td11"><!--l. 939--><p class="noindent" ><span class="cmr-12">The copy of the preconditioner data structure. Note that </span><span class="cmti-12">x </span><span class="cmr-12">must</span> <span class="cmr-12">be chosen according to the </span><span class="lstinline"></span><span class="cmtt-12">real</span><span class="cmr-12">/</span><span class="lstinline"></span><span class="cmtt-12">complex</span><span class="cmr-12">, single/double precision</span> <span class="cmr-12">version of AMG4PSBLAS under use.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-18-3-"><td style="white-space:normal; text-align:left;" id="TBL-18-3-1" class="td11"><!--l. 942--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">info</span> </td><td style="white-space:normal; text-align:left;" id="TBL-18-3-2" class="td11"><!--l. 942--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">integer</span><span class="cmtt-12">,</span><span class="cmtt-12"> </span><span class="cmtt-12">intent</span><span class="cmtt-12">(</span><span class="cmtt-12">out</span><span class="cmtt-12">)</span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-18-4-"><td style="white-space:normal; text-align:left;" id="TBL-18-4-1" class="td11"><!--l. 943--><p class="noindent" > </td><td style="white-space:normal; text-align:left;" id="TBL-18-4-2" class="td11"><!--l. 943--><p class="noindent" ><span class="cmr-12">Error code. If no error, 0 is returned. See Section</span><span class="cmr-12"> </span><a href="userhtmlse7.html#x28-320007"><span class="cmr-12">7</span><!--tex4ht:ref: sec:errors --></a> <span class="cmr-12">for details.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-18-5-"><td style="white-space:normal; text-align:left;" id="TBL-18-5-1" class="td11"> </td> </tr></table></div> <!--l. 948--><p class="noindent" > <h5 class="subsubsectionHead"><span class="titlemark"><span class="cmr-12">5.9.3 </span></span> <a id="x26-280005.9.3"></a><span class="cmr-12">Method: sizeof</span></h5> <div class="center" > <!--l. 950--><p class="noindent" > <!--l. 951--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">sz</span><span class="cmtt-12"> </span><span class="cmtt-12">=</span><span class="cmtt-12"> </span><span class="cmtt-12">p</span><span class="cmtt-12">%</span><span class="cmtt-12">sizeof</span><span class="cmtt-12">([</span><span class="cmtt-12">global</span><span class="cmtt-12">])</span><br /> </div> <div class="tabular"> <table id="TBL-19" class="tabular" cellspacing="0" cellpadding="0" ><colgroup id="TBL-19-1g"><col id="TBL-19-1"><col id="TBL-19-2"></colgroup><tr style="vertical-align:baseline;" id="TBL-19-1-"><td style="white-space:normal; text-align:left;" id="TBL-19-1-1" class="td11"><!--l. 955--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">global</span> </td> <td style="white-space:normal; text-align:left;" id="TBL-19-1-2" class="td11"><!--l. 955--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">logical</span><span class="cmtt-12">,</span><span class="cmtt-12"> </span><span class="cmtt-12">optional</span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-19-2-"><td style="white-space:normal; text-align:left;" id="TBL-19-2-1" class="td11"><!--l. 956--><p class="noindent" > </td><td style="white-space:normal; text-align:left;" id="TBL-19-2-2" class="td11"><!--l. 956--><p class="noindent" ><span class="cmr-12">Whether the global or local preconditioner memory occupation is</span> <span class="cmr-12">desired. Default: </span><span class="lstinline"></span><span class="cmtt-12">.</span><span class="cmtt-12">false</span><span class="cmtt-12">.</span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-19-3-"><td style="white-space:normal; text-align:left;" id="TBL-19-3-1" class="td11"> </td> </tr></table> </div> <span class="cmr-12">Return memory footprint in bytes.</span> <!--l. 963--><p class="noindent" > <h5 class="subsubsectionHead"><span class="titlemark"><span class="cmr-12">5.9.4 </span></span> <a id="x26-290005.9.4"></a><span class="cmr-12">Method: allocate</span><span class="cmr-12">_wrk</span></h5> <div class="center" > <!--l. 965--><p class="noindent" > <!--l. 966--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">call</span><span class="cmtt-12"> </span><span class="cmtt-12">p</span><span class="cmtt-12">%</span><span class="cmtt-12">allocate_wrk</span><span class="cmtt-12">(</span><span class="cmtt-12">info</span><span class="cmtt-12">[,</span><span class="cmtt-12"> </span><span class="cmtt-12">vmold</span><span class="cmtt-12">])</span><br /> </div> <!--l. 969--><p class="noindent" ><span class="cmr-12">Allocate internal work vectors. Each application of the preconditioner uses a number of</span> <span class="cmr-12">work vectors which are allocated internally as necessary; therefore allocation and</span> <span class="cmr-12">deallocation of memory occurs multiple times during the execution of a Krylov method.</span> <span class="cmr-12">In most cases this strategy is perfectly acceptable, but on some platforms, most</span> <span class="cmr-12">notably GPUs, memory allocation is a slow operation, and the default behaviour would</span> <span class="cmr-12">lead to a slowdown. This method allows to trade space for time by preallocating</span> <span class="cmr-12">the internal workspace outside of the invocation of a Krylov method. When</span> <span class="cmr-12">using GPUs or other specialized devices, the </span><span class="lstinline"></span><span class="cmtt-12">vmold</span> <span class="cmr-12">argument is also necessary</span> <span class="cmr-12">to ensure the internal work vectors are of the appropriate dynamic type to</span> <span class="cmr-12">exploit the accelerator hardware; when allocation occurs internally this is</span> <span class="cmr-12">taken care of based on the dynamic type of the </span><span class="lstinline"></span><span class="cmtt-12">x</span> <span class="cmr-12">argument to the </span><span class="lstinline"></span><span class="cmtt-12">apply</span> <span class="cmr-12">method.</span> <!--l. 985--><p class="noindent" ><span class="cmbx-12">Arguments</span> <div class="tabular"> <table id="TBL-20" class="tabular" cellspacing="0" cellpadding="0" ><colgroup id="TBL-20-1g"><col id="TBL-20-1"><col id="TBL-20-2"></colgroup><tr style="vertical-align:baseline;" id="TBL-20-1-"><td style="white-space:normal; text-align:left;" id="TBL-20-1-1" class="td11"><!--l. 988--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">info</span> </td><td style="white-space:normal; text-align:left;" id="TBL-20-1-2" class="td11"><!--l. 988--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">integer</span><span class="cmtt-12">,</span><span class="cmtt-12"> </span><span class="cmtt-12">intent</span><span class="cmtt-12">(</span><span class="cmtt-12">out</span><span class="cmtt-12">)</span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-20-2-"><td style="white-space:normal; text-align:left;" id="TBL-20-2-1" class="td11"><!--l. 989--><p class="noindent" > </td><td style="white-space:normal; text-align:left;" id="TBL-20-2-2" class="td11"><!--l. 989--><p class="noindent" ><span class="cmr-12">Error code. If no error, 0 is returned. See Section</span><span class="cmr-12"> </span><a href="userhtmlse7.html#x28-320007"><span class="cmr-12">7</span><!--tex4ht:ref: sec:errors --></a> <span class="cmr-12">for details.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-20-3-"><td style="white-space:normal; text-align:left;" id="TBL-20-3-1" class="td11"><!--l. 990--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">vmold</span> </td><td style="white-space:normal; text-align:left;" id="TBL-20-3-2" class="td11"><!--l. 990--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">class</span><span class="cmtt-12">(</span><span class="cmtt-12">psb_</span><span class="cmti-12">x</span><span class="lstinline"></span><span class="cmtt-12">_base_vect_type</span><span class="cmtt-12">),</span><span class="cmtt-12"> </span><span class="cmtt-12">intent</span><span class="cmtt-12">(</span><span class="cmtt-12">in</span><span class="cmtt-12">),</span><span class="cmtt-12"> </span><span class="cmtt-12">optional</span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-20-4-"><td style="white-space:normal; text-align:left;" id="TBL-20-4-1" class="td11"><!--l. 991--><p class="noindent" > </td><td style="white-space:normal; text-align:left;" id="TBL-20-4-2" class="td11"><!--l. 991--><p class="noindent" ><span class="cmr-12">The desired dynamic type for internal vector components; this</span> <span class="cmr-12">allows e.g. running on GPUs.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-20-5-"><td style="white-space:normal; text-align:left;" id="TBL-20-5-1" class="td11"> </td> </tr></table></div> <!--l. 997--><p class="noindent" > <h5 class="subsubsectionHead"><span class="titlemark"><span class="cmr-12">5.9.5 </span></span> <a id="x26-300005.9.5"></a><span class="cmr-12">Method: free</span><span class="cmr-12">_wrk</span></h5> <div class="center" > <!--l. 999--><p class="noindent" > <!--l. 1000--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">call</span><span class="cmtt-12"> </span><span class="cmtt-12">p</span><span class="cmtt-12">%</span><span class="cmtt-12">free_wrk</span><span class="cmtt-12">(</span><span class="cmtt-12">info</span><span class="cmtt-12">)</span><br /> </div> <!--l. 1003--><p class="noindent" ><span class="cmr-12">Deallocate internal work vectors.</span> <!--l. 1006--><p class="noindent" ><span class="cmbx-12">Arguments</span> <div class="tabular"> <table id="TBL-21" class="tabular" cellspacing="0" cellpadding="0" ><colgroup id="TBL-21-1g"><col id="TBL-21-1"><col id="TBL-21-2"></colgroup><tr style="vertical-align:baseline;" id="TBL-21-1-"><td style="white-space:normal; text-align:left;" id="TBL-21-1-1" class="td11"><!--l. 1009--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">info</span> </td><td style="white-space:normal; text-align:left;" id="TBL-21-1-2" class="td11"><!--l. 1009--><p class="noindent" ><span class="lstinline"></span><span class="cmtt-12">integer</span><span class="cmtt-12">,</span><span class="cmtt-12"> </span><span class="cmtt-12">intent</span><span class="cmtt-12">(</span><span class="cmtt-12">out</span><span class="cmtt-12">)</span><span class="cmr-12">.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-21-2-"><td style="white-space:normal; text-align:left;" id="TBL-21-2-1" class="td11"><!--l. 1010--><p class="noindent" > </td><td style="white-space:normal; text-align:left;" id="TBL-21-2-2" class="td11"><!--l. 1010--><p class="noindent" ><span class="cmr-12">Error code. If no error, 0 is returned. See Section</span><span class="cmr-12"> </span><a href="userhtmlse7.html#x28-320007"><span class="cmr-12">7</span><!--tex4ht:ref: sec:errors --></a> <span class="cmr-12">for details.</span> </td> </tr><tr style="vertical-align:baseline;" id="TBL-21-3-"><td style="white-space:normal; text-align:left;" id="TBL-21-3-1" class="td11"> </td> </tr></table></div> <!--l. 4--><div class="crosslinks"><p class="noindent"><span class="cmr-12">[</span><a href="userhtmlsu15.html" ><span class="cmr-12">prev</span></a><span class="cmr-12">] [</span><a href="userhtmlsu15.html#tailuserhtmlsu15.html" ><span class="cmr-12">prev-tail</span></a><span class="cmr-12">] [</span><a href="userhtmlsu16.html" ><span class="cmr-12">front</span></a><span class="cmr-12">] [</span><a href="userhtmlse5.html#userhtmlsu16.html" ><span class="cmr-12">up</span></a><span class="cmr-12">] </span></p></div> <!--l. 4--><p class="indent" > <a id="tailuserhtmlsu16.html"></a> </body></html>