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<center><a href="ex7.c">Actual source code: ex7.c</a></center><br>
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<pre width="80"><a name="line1"> 1: </a><font color="#B22222">/*$Id: ex7.c,v 1.20 2001/09/11 16:33:24 bsmith Exp $*/</font>
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<a name="line3"> 3: </a>static char help[] = <font color="#666666">"Reads a PETSc matrix and vector from a file and solves a linear system.\n\</font>
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<a name="line4"> 4: </a><font color="#666666"> Tests inplace factorization for SeqBAIJ. Input parameters include\n\</font>
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<a name="line5"> 5: </a><font color="#666666"> -f0 <input_file> : first file to load (small system)\n\n"</font>;
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<a name="line7"> 7: </a><font color="#B22222">/*T</font>
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<a name="line8"> 8: </a><font color="#B22222"> Concepts: <A href="../../../../docs/manualpages/KSP/KSP.html#KSP">KSP</A>^solving a linear system</font>
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<a name="line9"> 9: </a><font color="#B22222"> Concepts: PetscLog^profiling multiple stages of code;</font>
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<a name="line10"> 10: </a><font color="#B22222"> Processors: n</font>
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<a name="line11"> 11: </a><font color="#B22222">T*/</font>
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<a name="line13"> 13: </a><font color="#B22222">/* </font>
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<a name="line14"> 14: </a><font color="#B22222"> Include "petscksp.h" so that we can use <A href="../../../../docs/manualpages/KSP/KSP.html#KSP">KSP</A> solvers. Note that this file</font>
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<a name="line15"> 15: </a><font color="#B22222"> automatically includes:</font>
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<a name="line16"> 16: </a><font color="#B22222"> petsc.h - base PETSc routines petscvec.h - vectors</font>
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<a name="line17"> 17: </a><font color="#B22222"> petscsys.h - system routines petscmat.h - matrices</font>
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<a name="line18"> 18: </a><font color="#B22222"> petscis.h - index sets petscksp.h - Krylov subspace methods</font>
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<a name="line19"> 19: </a><font color="#B22222"> petscviewer.h - viewers petscpc.h - preconditioners</font>
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<a name="line20"> 20: </a><font color="#B22222">*/</font>
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<a name="line21"> 21: </a> #include <A href="../../../../include/petscksp.h.html">petscksp.h</A>
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<a name="line25"> 25: </a><strong><font color="#4169E1"><a name="main"></a>int main(int argc,char **args)</font></strong>
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<a name="line26"> 26: </a>{
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<a name="line27"> 27: </a> <A href="../../../../docs/manualpages/KSP/KSP.html#KSP">KSP</A> ksp; <font color="#B22222">/* linear solver context */</font>
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<a name="line28"> 28: </a> <A href="../../../../docs/manualpages/Mat/Mat.html#Mat">Mat</A> A,B; <font color="#B22222">/* matrix */</font>
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<a name="line29"> 29: </a> <A href="../../../../docs/manualpages/Vec/Vec.html#Vec">Vec</A> x,b,u; <font color="#B22222">/* approx solution, RHS, exact solution */</font>
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<a name="line30"> 30: </a> <A href="../../../../docs/manualpages/Viewer/PetscViewer.html#PetscViewer">PetscViewer</A> fd; <font color="#B22222">/* viewer */</font>
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<a name="line31"> 31: </a> char file[2][128]; <font color="#B22222">/* input file name */</font>
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<a name="line32"> 32: </a> int ierr,its;
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<a name="line33"> 33: </a> <A href="../../../../docs/manualpages/Sys/PetscTruth.html#PetscTruth">PetscTruth</A> flg;
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<a name="line34"> 34: </a> <A href="../../../../docs/manualpages/Sys/PetscReal.html#PetscReal">PetscReal</A> norm;
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<a name="line35"> 35: </a> <A href="../../../../docs/manualpages/Sys/PetscScalar.html#PetscScalar">PetscScalar</A> zero = 0.0,none = -1.0;
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<a name="line37"> 37: </a> <A href="../../../../docs/manualpages/Sys/PetscInitialize.html#PetscInitialize">PetscInitialize</A>(&argc,&args,(char *)0,help);
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<a name="line39"> 39: </a> <font color="#B22222">/* </font>
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<a name="line40"> 40: </a><font color="#B22222"> Determine files from which we read the two linear systems</font>
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<a name="line41"> 41: </a><font color="#B22222"> (matrix and right-hand-side vector).</font>
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<a name="line42"> 42: </a><font color="#B22222"> */</font>
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<a name="line43"> 43: </a> <A href="../../../../docs/manualpages/Sys/PetscOptionsGetString.html#PetscOptionsGetString">PetscOptionsGetString</A>(<A href="../../../../docs/manualpages/Sys/PETSC_NULL.html#PETSC_NULL">PETSC_NULL</A>,<font color="#666666">"-f0"</font>,file[0],127,&flg);
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<a name="line44"> 44: </a> <font color="#4169E1">if</font> (!flg) <A href="../../../../docs/manualpages/Sys/SETERRQ.html#SETERRQ">SETERRQ</A>(1,<font color="#666666">"Must indicate binary file with the -f0 option"</font>);
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<a name="line47"> 47: </a> <font color="#B22222">/* </font>
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<a name="line48"> 48: </a><font color="#B22222"> Open binary file. Note that we use PETSC_FILE_RDONLY to indicate</font>
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<a name="line49"> 49: </a><font color="#B22222"> reading from this file.</font>
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<a name="line50"> 50: </a><font color="#B22222"> */</font>
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<a name="line51"> 51: </a> <A href="../../../../docs/manualpages/Viewer/PetscViewerBinaryOpen.html#PetscViewerBinaryOpen">PetscViewerBinaryOpen</A>(<A href="../../../../docs/manualpages/Sys/PETSC_COMM_WORLD.html#PETSC_COMM_WORLD">PETSC_COMM_WORLD</A>,file[0],PETSC_FILE_RDONLY,&fd);
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<a name="line53"> 53: </a> <font color="#B22222">/*</font>
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<a name="line54"> 54: </a><font color="#B22222"> Load the matrix and vector; then destroy the viewer.</font>
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<a name="line55"> 55: </a><font color="#B22222"> */</font>
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<a name="line56"> 56: </a> <A href="../../../../docs/manualpages/Mat/MatLoad.html#MatLoad">MatLoad</A>(fd,<A href="../../../../docs/manualpages/Mat/MATSEQBAIJ.html#MATSEQBAIJ">MATSEQBAIJ</A>,&A);
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<a name="line57"> 57: </a> <A href="../../../../docs/manualpages/Mat/MatConvert.html#MatConvert">MatConvert</A>(A,MATSAME,&B);
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<a name="line58"> 58: </a> <A href="../../../../docs/manualpages/Vec/VecLoad.html#VecLoad">VecLoad</A>(fd,<A href="../../../../docs/manualpages/Sys/PETSC_NULL.html#PETSC_NULL">PETSC_NULL</A>,&b);
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<a name="line59"> 59: </a> <A href="../../../../docs/manualpages/Viewer/PetscViewerDestroy.html#PetscViewerDestroy">PetscViewerDestroy</A>(fd);
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<a name="line61"> 61: </a> <font color="#B22222">/* </font>
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<a name="line62"> 62: </a><font color="#B22222"> If the loaded matrix is larger than the vector (due to being padded </font>
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<a name="line63"> 63: </a><font color="#B22222"> to match the block <A href="../../../../docs/manualpages/Sys/size.html#size">size</A> of the system), then create a new padded vector.</font>
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<a name="line64"> 64: </a><font color="#B22222"> */</font>
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<a name="line65"> 65: </a> {
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<a name="line66"> 66: </a> int m,n,j,mvec,start,end,idx;
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<a name="line67"> 67: </a> <A href="../../../../docs/manualpages/Vec/Vec.html#Vec">Vec</A> tmp;
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<a name="line68"> 68: </a> <A href="../../../../docs/manualpages/Sys/PetscScalar.html#PetscScalar">PetscScalar</A> *bold;
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<a name="line70"> 70: </a> <font color="#B22222">/* Create a new vector b by padding the old one */</font>
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<a name="line71"> 71: </a> <A href="../../../../docs/manualpages/Mat/MatGetLocalSize.html#MatGetLocalSize">MatGetLocalSize</A>(A,&m,&n);
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<a name="line72"> 72: </a> <A href="../../../../docs/manualpages/Vec/VecCreate.html#VecCreate">VecCreate</A>(<A href="../../../../docs/manualpages/Sys/PETSC_COMM_WORLD.html#PETSC_COMM_WORLD">PETSC_COMM_WORLD</A>,&tmp);
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<a name="line73"> 73: </a> <A href="../../../../docs/manualpages/Vec/VecSetSizes.html#VecSetSizes">VecSetSizes</A>(tmp,m,<A href="../../../../docs/manualpages/Sys/PETSC_DECIDE.html#PETSC_DECIDE">PETSC_DECIDE</A>);
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<a name="line74"> 74: </a> <A href="../../../../docs/manualpages/Vec/VecSetFromOptions.html#VecSetFromOptions">VecSetFromOptions</A>(tmp);
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<a name="line75"> 75: </a> <A href="../../../../docs/manualpages/Vec/VecGetOwnershipRange.html#VecGetOwnershipRange">VecGetOwnershipRange</A>(b,&start,&end);
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<a name="line76"> 76: </a> <A href="../../../../docs/manualpages/Vec/VecGetLocalSize.html#VecGetLocalSize">VecGetLocalSize</A>(b,&mvec);
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<a name="line77"> 77: </a> <A href="../../../../docs/manualpages/Vec/VecGetArray.html#VecGetArray">VecGetArray</A>(b,&bold);
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<a name="line78"> 78: </a> <font color="#4169E1">for</font> (j=0; j<mvec; j++) {
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<a name="line79"> 79: </a> idx = start+j;
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<a name="line80"> 80: </a> <A href="../../../../docs/manualpages/Vec/VecSetValues.html#VecSetValues">VecSetValues</A>(tmp,1,&idx,bold+j,INSERT_VALUES);
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<a name="line81"> 81: </a> }
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<a name="line82"> 82: </a> <A href="../../../../docs/manualpages/Vec/VecRestoreArray.html#VecRestoreArray">VecRestoreArray</A>(b,&bold);
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<a name="line83"> 83: </a> <A href="../../../../docs/manualpages/Vec/VecDestroy.html#VecDestroy">VecDestroy</A>(b);
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<a name="line84"> 84: </a> <A href="../../../../docs/manualpages/Vec/VecAssemblyBegin.html#VecAssemblyBegin">VecAssemblyBegin</A>(tmp);
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<a name="line85"> 85: </a> <A href="../../../../docs/manualpages/Vec/VecAssemblyEnd.html#VecAssemblyEnd">VecAssemblyEnd</A>(tmp);
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<a name="line86"> 86: </a> b = tmp;
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<a name="line87"> 87: </a> }
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<a name="line88"> 88: </a> <A href="../../../../docs/manualpages/Vec/VecDuplicate.html#VecDuplicate">VecDuplicate</A>(b,&x);
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<a name="line89"> 89: </a> <A href="../../../../docs/manualpages/Vec/VecDuplicate.html#VecDuplicate">VecDuplicate</A>(b,&u);
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<a name="line90"> 90: </a> <A href="../../../../docs/manualpages/Vec/VecSet.html#VecSet">VecSet</A>(&zero,x);
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<a name="line92"> 92: </a> <font color="#B22222">/*</font>
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<a name="line93"> 93: </a><font color="#B22222"> Create linear solver; set operators; set runtime options.</font>
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<a name="line94"> 94: </a><font color="#B22222"> */</font>
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<a name="line95"> 95: </a> <A href="../../../../docs/manualpages/KSP/KSPCreate.html#KSPCreate">KSPCreate</A>(<A href="../../../../docs/manualpages/Sys/PETSC_COMM_WORLD.html#PETSC_COMM_WORLD">PETSC_COMM_WORLD</A>,&ksp);
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<a name="line96"> 96: </a> <A href="../../../../docs/manualpages/KSP/KSPSetOperators.html#KSPSetOperators">KSPSetOperators</A>(ksp,A,B,DIFFERENT_NONZERO_PATTERN);
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<a name="line97"> 97: </a> <A href="../../../../docs/manualpages/KSP/KSPSetFromOptions.html#KSPSetFromOptions">KSPSetFromOptions</A>(ksp);
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<a name="line99"> 99: </a> <font color="#B22222">/* </font>
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<a name="line100">100: </a><font color="#B22222"> Here we explicitly call <A href="../../../../docs/manualpages/KSP/KSPSetUp.html#KSPSetUp">KSPSetUp</A>() and <A href="../../../../docs/manualpages/KSP/KSPSetUpOnBlocks.html#KSPSetUpOnBlocks">KSPSetUpOnBlocks</A>() to</font>
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<a name="line101">101: </a><font color="#B22222"> enable more precise profiling of setting up the preconditioner.</font>
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<a name="line102">102: </a><font color="#B22222"> These calls are optional, since both will be called within</font>
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<a name="line103">103: </a><font color="#B22222"> <A href="../../../../docs/manualpages/KSP/KSPSolve.html#KSPSolve">KSPSolve</A>() if they haven't been called already.</font>
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<a name="line104">104: </a><font color="#B22222"> */</font>
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<a name="line105">105: </a> <A href="../../../../docs/manualpages/KSP/KSPSetRhs.html#KSPSetRhs">KSPSetRhs</A>(ksp,b);
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<a name="line106">106: </a> <A href="../../../../docs/manualpages/KSP/KSPSetSolution.html#KSPSetSolution">KSPSetSolution</A>(ksp,x);
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<a name="line107">107: </a> <A href="../../../../docs/manualpages/KSP/KSPSetUp.html#KSPSetUp">KSPSetUp</A>(ksp);
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<a name="line108">108: </a> <A href="../../../../docs/manualpages/KSP/KSPSetUpOnBlocks.html#KSPSetUpOnBlocks">KSPSetUpOnBlocks</A>(ksp);
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<a name="line109">109: </a> <A href="../../../../docs/manualpages/KSP/KSPSolve.html#KSPSolve">KSPSolve</A>(ksp);
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<a name="line111">111: </a> <font color="#B22222">/*</font>
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<a name="line112">112: </a><font color="#B22222"> Check error, print output, free data structures.</font>
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<a name="line113">113: </a><font color="#B22222"> This stage is not profiled separately.</font>
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<a name="line114">114: </a><font color="#B22222"> - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */</font>
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<a name="line116">116: </a> <font color="#B22222">/* </font>
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<a name="line117">117: </a><font color="#B22222"> Check error</font>
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<a name="line118">118: </a><font color="#B22222"> */</font>
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<a name="line119">119: </a> <A href="../../../../docs/manualpages/Mat/MatMult.html#MatMult">MatMult</A>(A,x,u);
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<a name="line120">120: </a> <A href="../../../../docs/manualpages/Vec/VecAXPY.html#VecAXPY">VecAXPY</A>(&none,b,u);
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<a name="line121">121: </a> <A href="../../../../docs/manualpages/Vec/VecNorm.html#VecNorm">VecNorm</A>(u,NORM_2,&norm);
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<a name="line122">122: </a> <A href="../../../../docs/manualpages/KSP/KSPGetIterationNumber.html#KSPGetIterationNumber">KSPGetIterationNumber</A>(ksp,&its);
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<a name="line123">123: </a> <A href="../../../../docs/manualpages/Sys/PetscPrintf.html#PetscPrintf">PetscPrintf</A>(<A href="../../../../docs/manualpages/Sys/PETSC_COMM_WORLD.html#PETSC_COMM_WORLD">PETSC_COMM_WORLD</A>,<font color="#666666">"Number of iterations = %3d\n"</font>,its);
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<a name="line124">124: </a> <A href="../../../../docs/manualpages/Sys/PetscPrintf.html#PetscPrintf">PetscPrintf</A>(<A href="../../../../docs/manualpages/Sys/PETSC_COMM_WORLD.html#PETSC_COMM_WORLD">PETSC_COMM_WORLD</A>,<font color="#666666">"Residual norm = %A\n"</font>,norm);
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<a name="line126">126: </a> <font color="#B22222">/* </font>
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<a name="line127">127: </a><font color="#B22222"> Free work space. All PETSc objects should be destroyed when they</font>
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<a name="line128">128: </a><font color="#B22222"> are no longer needed.</font>
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<a name="line129">129: </a><font color="#B22222"> */</font>
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<a name="line130">130: </a> <A href="../../../../docs/manualpages/Mat/MatDestroy.html#MatDestroy">MatDestroy</A>(A);
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<a name="line131">131: </a> <A href="../../../../docs/manualpages/Mat/MatDestroy.html#MatDestroy">MatDestroy</A>(B);
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<a name="line132">132: </a> <A href="../../../../docs/manualpages/Vec/VecDestroy.html#VecDestroy">VecDestroy</A>(b);
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<a name="line133">133: </a> <A href="../../../../docs/manualpages/Vec/VecDestroy.html#VecDestroy">VecDestroy</A>(u); <A href="../../../../docs/manualpages/Vec/VecDestroy.html#VecDestroy">VecDestroy</A>(x);
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<a name="line134">134: </a> <A href="../../../../docs/manualpages/KSP/KSPDestroy.html#KSPDestroy">KSPDestroy</A>(ksp);
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<a name="line137">137: </a> <A href="../../../../docs/manualpages/Sys/PetscFinalize.html#PetscFinalize">PetscFinalize</A>();
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<a name="line138">138: </a> <font color="#4169E1">return</font> 0;
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<a name="line139">139: </a>}