<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html><head><meta http-equiv="Content-Type" content="text/html;charset=UTF-8"> <title>SuperLU: SRC/dgssv.c File Reference</title> <link href="doxygen.css" rel="stylesheet" type="text/css"> <link href="tabs.css" rel="stylesheet" type="text/css"> </head><body> <!-- Generated by Doxygen 1.5.5 --> <div class="navigation" id="top"> <div class="tabs"> <ul> <li><a href="index.html"><span>Main Page</span></a></li> <li><a href="annotated.html"><span>Data Structures</span></a></li> <li class="current"><a href="files.html"><span>Files</span></a></li> </ul> </div> </div> <div class="contents"> <h1>SRC/dgssv.c File Reference</h1>Solves the system of linear equations A*X=B. <a href="#_details">More...</a> <p> <code>#include "<a class="el" href="slu__ddefs_8h-source.html">slu_ddefs.h</a>"</code><br> <table border="0" cellpadding="0" cellspacing="0"> <tr><td></td></tr> <tr><td colspan="2"><br><h2>Functions</h2></td></tr> <tr><td class="memItemLeft" nowrap align="right" valign="top">void </td><td class="memItemRight" valign="bottom"><a class="el" href="dgssv_8c.html#d804a93a6806ee4d4694df5b753d91af">dgssv</a> (<a class="el" href="structsuperlu__options__t.html">superlu_options_t</a> *options, <a class="el" href="structSuperMatrix.html">SuperMatrix</a> *<a class="el" href="ilu__zdrop__row_8c.html#c900805a486cbb8489e3c176ed6e0d8e">A</a>, int *perm_c, int *perm_r, <a class="el" href="structSuperMatrix.html">SuperMatrix</a> *L, <a class="el" href="structSuperMatrix.html">SuperMatrix</a> *U, <a class="el" href="structSuperMatrix.html">SuperMatrix</a> *B, <a class="el" href="structSuperLUStat__t.html">SuperLUStat_t</a> *stat, int *info)</td></tr> <tr><td class="mdescLeft"> </td><td class="mdescRight">Driver routines. <a href="#d804a93a6806ee4d4694df5b753d91af"></a><br></td></tr> </table> <hr><a name="_details"></a><h2>Detailed Description</h2> <pre> -- SuperLU routine (version 3.0) -- Univ. of California Berkeley, Xerox Palo Alto Research Center, and Lawrence Berkeley National Lab. October 15, 2003 </pre> <hr><h2>Function Documentation</h2> <a class="anchor" name="d804a93a6806ee4d4694df5b753d91af"></a><!-- doxytag: member="dgssv.c::dgssv" ref="d804a93a6806ee4d4694df5b753d91af" args="(superlu_options_t *options, SuperMatrix *A, int *perm_c, int *perm_r, SuperMatrix *L, SuperMatrix *U, SuperMatrix *B, SuperLUStat_t *stat, int *info)" --> <div class="memitem"> <div class="memproto"> <table class="memname"> <tr> <td class="memname">void dgssv </td> <td>(</td> <td class="paramtype"><a class="el" href="structsuperlu__options__t.html">superlu_options_t</a> * </td> <td class="paramname"> <em>options</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype"><a class="el" href="structSuperMatrix.html">SuperMatrix</a> * </td> <td class="paramname"> <em>A</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype">int * </td> <td class="paramname"> <em>perm_c</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype">int * </td> <td class="paramname"> <em>perm_r</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype"><a class="el" href="structSuperMatrix.html">SuperMatrix</a> * </td> <td class="paramname"> <em>L</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype"><a class="el" href="structSuperMatrix.html">SuperMatrix</a> * </td> <td class="paramname"> <em>U</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype"><a class="el" href="structSuperMatrix.html">SuperMatrix</a> * </td> <td class="paramname"> <em>B</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype"><a class="el" href="structSuperLUStat__t.html">SuperLUStat_t</a> * </td> <td class="paramname"> <em>stat</em>, </td> </tr> <tr> <td class="paramkey"></td> <td></td> <td class="paramtype">int * </td> <td class="paramname"> <em>info</em></td><td> </td> </tr> <tr> <td></td> <td>)</td> <td></td><td></td><td width="100%"></td> </tr> </table> </div> <div class="memdoc"> <p> <pre> Purpose =======</pre><p> <pre> DGSSV solves the system of linear equations A*X=B, using the LU factorization from DGSTRF. It performs the following steps:</pre><p> <pre> 1. If A is stored column-wise (A->Stype = SLU_NC):</pre><p> <pre> 1.1. Permute the columns of A, forming A*Pc, where Pc is a permutation matrix. For more details of this step, see <a class="el" href="sp__preorder_8c.html" title="Permute and performs functions on columns of orginal matrix.">sp_preorder.c</a>.</pre><p> <pre> 1.2. Factor A as Pr*A*Pc=L*U with the permutation Pr determined by Gaussian elimination with partial pivoting. L is unit lower triangular with offdiagonal entries bounded by 1 in magnitude, and U is upper triangular.</pre><p> <pre> 1.3. Solve the system of equations A*X=B using the factored form of A.</pre><p> <pre> 2. If A is stored row-wise (A->Stype = SLU_NR), apply the above algorithm to the transpose of A:</pre><p> <pre> 2.1. Permute columns of transpose(A) (rows of A), forming transpose(A)*Pc, where Pc is a permutation matrix. For more details of this step, see <a class="el" href="sp__preorder_8c.html" title="Permute and performs functions on columns of orginal matrix.">sp_preorder.c</a>.</pre><p> <pre> 2.2. Factor A as Pr*transpose(A)*Pc=L*U with the permutation Pr determined by Gaussian elimination with partial pivoting. L is unit lower triangular with offdiagonal entries bounded by 1 in magnitude, and U is upper triangular.</pre><p> <pre> 2.3. Solve the system of equations A*X=B using the factored form of A.</pre><p> <pre> See <a class="el" href="supermatrix_8h.html" title="Defines matrix types.">supermatrix.h</a> for the definition of 'SuperMatrix' structure.</pre><p> <pre> Arguments =========</pre><p> <pre> options (input) superlu_options_t* The structure defines the input parameters to control how the LU decomposition will be performed and how the system will be solved.</pre><p> <pre> A (input) SuperMatrix* Matrix A in A*X=B, of dimension (A->nrow, A->ncol). The number of linear equations is A->nrow. Currently, the type of A can be: Stype = SLU_NC or SLU_NR; Dtype = SLU_D; Mtype = SLU_GE. In the future, more general A may be handled.</pre><p> <pre> perm_c (input/output) int* If A->Stype = SLU_NC, column permutation vector of size A->ncol which defines the permutation matrix Pc; perm_c[i] = j means column i of A is in position j in A*Pc. If A->Stype = SLU_NR, column permutation vector of size A->nrow which describes permutation of columns of transpose(A) (rows of A) as described above.</pre><p> <pre> If options->ColPerm = MY_PERMC or options->Fact = SamePattern or options->Fact = SamePattern_SameRowPerm, it is an input argument. On exit, perm_c may be overwritten by the product of the input perm_c and a permutation that postorders the elimination tree of Pc'*A'*A*Pc; perm_c is not changed if the elimination tree is already in postorder. Otherwise, it is an output argument.</pre><p> <pre> perm_r (input/output) int* If A->Stype = SLU_NC, row permutation vector of size A->nrow, which defines the permutation matrix Pr, and is determined by partial pivoting. perm_r[i] = j means row i of A is in position j in Pr*A. If A->Stype = SLU_NR, permutation vector of size A->ncol, which determines permutation of rows of transpose(A) (columns of A) as described above.</pre><p> <pre> If options->RowPerm = MY_PERMR or options->Fact = SamePattern_SameRowPerm, perm_r is an input argument. otherwise it is an output argument.</pre><p> <pre> L (output) SuperMatrix* The factor L from the factorization Pr*A*Pc=L*U (if A->Stype = SLU_NC) or Pr*transpose(A)*Pc=L*U (if A->Stype = SLU_NR). Uses compressed row subscripts storage for supernodes, i.e., L has types: Stype = SLU_SC, Dtype = SLU_D, Mtype = SLU_TRLU.</pre><p> <pre> U (output) SuperMatrix* The factor U from the factorization Pr*A*Pc=L*U (if A->Stype = SLU_NC) or Pr*transpose(A)*Pc=L*U (if A->Stype = SLU_NR). Uses column-wise storage scheme, i.e., U has types: Stype = SLU_NC, Dtype = SLU_D, Mtype = SLU_TRU.</pre><p> <pre> B (input/output) SuperMatrix* B has types: Stype = SLU_DN, Dtype = SLU_D, Mtype = SLU_GE. On entry, the right hand side matrix. On exit, the solution matrix if info = 0;</pre><p> <pre> stat (output) SuperLUStat_t* Record the statistics on runtime and floating-point operation count. See util.h for the definition of 'SuperLUStat_t'.</pre><p> <pre> info (output) int* = 0: successful exit > 0: if info = i, and i is <= A->ncol: U(i,i) is exactly zero. The factorization has been completed, but the factor U is exactly singular, so the solution could not be computed. > A->ncol: number of bytes allocated when memory allocation failure occurred, plus A->ncol. </pre> </div> </div><p> </div> <hr size="1"><address style="text-align: right;"><small>Generated on Thu Aug 25 13:43:49 2011 for SuperLU by <a href="http://www.doxygen.org/index.html"> <img src="doxygen.png" alt="doxygen" align="middle" border="0"></a> 1.5.5 </small></address> </body> </html>