static char help[] = "Tests cholesky, icc factorization and solve on sequential aij, baij and sbaij matrices. \n";

#include "petscmat.h"

#undef __FUNCT__
#define __FUNCT__ "main"
int main(int argc,char **args)
{
  Vec            x,y,b;
  Mat            A;           /* linear system matrix */ 
  Mat            sA,sC;       /* symmetric part of the matrices */ 
  PetscInt       n,mbs=16,bs=1,nz=3,prob=1,i,j,col[3],block, row,Ii,J,n1,lvl;
  PetscErrorCode ierr;
  PetscMPIInt    size;
  PetscReal      norm2,tol=1.e-10,err[10];
  PetscScalar    neg_one = -1.0,four=4.0,value[3];  
  IS             perm,cperm;
  PetscRandom    rdm;
  PetscInt       reorder=0,displ=0;
  MatFactorInfo  factinfo;
  PetscTruth     equal;
  PetscTruth     TestAIJ=PETSC_FALSE,TestBAIJ=PETSC_TRUE;
  PetscInt       TestShift=0;

  PetscInitialize(&argc,&args,(char *)0,help);
  ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);
  if (size != 1) SETERRQ(1,"This is a uniprocessor example only!");
  ierr = PetscOptionsGetInt(PETSC_NULL,"-bs",&bs,PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsGetInt(PETSC_NULL,"-mbs",&mbs,PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsGetInt(PETSC_NULL,"-reorder",&reorder,PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsGetTruth(PETSC_NULL,"-testaij",&TestAIJ,PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsGetInt(PETSC_NULL,"-testShift",&TestShift,PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscOptionsGetInt(PETSC_NULL,"-displ",&displ,PETSC_NULL);CHKERRQ(ierr);

  n = mbs*bs;
  if (TestAIJ){ /* A is in aij format */
    ierr = MatCreateSeqAIJ(PETSC_COMM_WORLD,n,n,nz,PETSC_NULL,&A);CHKERRQ(ierr);
    TestBAIJ = PETSC_FALSE;
  } else { /* A is in baij format */
    ierr=MatCreateSeqBAIJ(PETSC_COMM_WORLD,bs,n,n,nz,PETSC_NULL,&A);CHKERRQ(ierr);
    TestAIJ = PETSC_FALSE;
  }

  /* Assemble matrix */
  if (bs == 1){
    ierr = PetscOptionsGetInt(PETSC_NULL,"-test_problem",&prob,PETSC_NULL);CHKERRQ(ierr);
    if (prob == 1){ /* tridiagonal matrix */
      value[0] = -1.0; value[1] = 2.0; value[2] = -1.0;
      for (i=1; i<n-1; i++) {
        col[0] = i-1; col[1] = i; col[2] = i+1;
        ierr = MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);CHKERRQ(ierr);
      }
      i = n - 1; col[0]=0; col[1] = n - 2; col[2] = n - 1;
      value[0]= 0.1; value[1]=-1; value[2]=2;
      ierr = MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);CHKERRQ(ierr);

      i = 0; col[0] = 0; col[1] = 1; col[2]=n-1;
      value[0] = 2.0; value[1] = -1.0; value[2]=0.1;
      ierr = MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);CHKERRQ(ierr);
    } else if (prob ==2){ /* matrix for the five point stencil */
      n1 = (int) (sqrt((PetscReal)n) + 0.001); 
      if (n1*n1 - n) SETERRQ(PETSC_ERR_ARG_WRONG,"sqrt(n) must be a positive interger!"); 
      for (i=0; i<n1; i++) {
        for (j=0; j<n1; j++) {
          Ii = j + n1*i;
          if (i>0)   {
            J = Ii - n1; 
            ierr = MatSetValues(A,1,&Ii,1,&J,&neg_one,INSERT_VALUES);CHKERRQ(ierr); 
          }
          if (i<n1-1) {
            J = Ii + n1; 
            ierr = MatSetValues(A,1,&Ii,1,&J,&neg_one,INSERT_VALUES);CHKERRQ(ierr);
          }
          if (j>0)   {
            J = Ii - 1; 
            ierr = MatSetValues(A,1,&Ii,1,&J,&neg_one,INSERT_VALUES);CHKERRQ(ierr);
          }
          if (j<n1-1) {
            J = Ii + 1; 
            ierr = MatSetValues(A,1,&Ii,1,&J,&neg_one,INSERT_VALUES);CHKERRQ(ierr);
          }
          ierr = MatSetValues(A,1,&Ii,1,&Ii,&four,INSERT_VALUES);CHKERRQ(ierr);
        }
      }                   
    }
  } else { /* bs > 1 */
    for (block=0; block<n/bs; block++){
      /* diagonal blocks */
      value[0] = -1.0; value[1] = 4.0; value[2] = -1.0;
      for (i=1+block*bs; i<bs-1+block*bs; i++) {
        col[0] = i-1; col[1] = i; col[2] = i+1;
        ierr = MatSetValues(A,1,&i,3,col,value,INSERT_VALUES);CHKERRQ(ierr);   
      }
      i = bs - 1+block*bs; col[0] = bs - 2+block*bs; col[1] = bs - 1+block*bs;
      value[0]=-1.0; value[1]=4.0;  
      ierr = MatSetValues(A,1,&i,2,col,value,INSERT_VALUES);CHKERRQ(ierr);

      i = 0+block*bs; col[0] = 0+block*bs; col[1] = 1+block*bs; 
      value[0]=4.0; value[1] = -1.0; 
      ierr = MatSetValues(A,1,&i,2,col,value,INSERT_VALUES);CHKERRQ(ierr);  
    }
    /* off-diagonal blocks */
    value[0]=-1.0;
    for (i=0; i<(n/bs-1)*bs; i++){
      col[0]=i+bs;
      ierr = MatSetValues(A,1,&i,1,col,value,INSERT_VALUES);CHKERRQ(ierr);
      col[0]=i; row=i+bs;
      ierr = MatSetValues(A,1,&row,1,col,value,INSERT_VALUES);CHKERRQ(ierr);
    }
  }

  if (TestShift){
     /* set diagonals in the 0-th block as 0 for testing shift numerical factor */
     for (i=0; i<bs; i++){
       row = i; col[0] = i; value[0] = 0.0;
       ierr = MatSetValues(A,1,&row,1,col,value,INSERT_VALUES);CHKERRQ(ierr);
     }
   }

  ierr = MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
  ierr = MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);

  /* Test MatConvert */
  ierr = MatConvert(A,MATSEQSBAIJ,MAT_INITIAL_MATRIX,&sA);CHKERRQ(ierr); 
  ierr = MatMultEqual(A,sA,20,&equal);CHKERRQ(ierr);
  if (!equal) SETERRQ(PETSC_ERR_USER,"A != sA");

  /* Test MatGetOwnershipRange() */
  ierr = MatGetOwnershipRange(A,&Ii,&J);CHKERRQ(ierr);
  ierr = MatGetOwnershipRange(sA,&i,&j);CHKERRQ(ierr);
  if (i-Ii || j-J){
    PetscPrintf(PETSC_COMM_SELF,"Error: MatGetOwnershipRange() in MatSBAIJ format\n");
  }

  /* Vectors */
  ierr = PetscRandomCreate(PETSC_COMM_SELF,&rdm);CHKERRQ(ierr);
  ierr = PetscRandomSetFromOptions(rdm);CHKERRQ(ierr);
  ierr = VecCreateSeq(PETSC_COMM_SELF,n,&x);CHKERRQ(ierr);
  ierr = VecDuplicate(x,&b);CHKERRQ(ierr);
  ierr = VecDuplicate(x,&y);CHKERRQ(ierr);
  ierr = VecSetRandom(x,rdm);CHKERRQ(ierr);

  /* Test MatReordering() - not work on sbaij matrix */
  if (reorder){
    ierr = MatGetOrdering(A,MATORDERING_RCM,&perm,&cperm);CHKERRQ(ierr);
  } else {
    ierr = MatGetOrdering(A,MATORDERING_NATURAL,&perm,&cperm);CHKERRQ(ierr);
  }
  ierr = ISDestroy(cperm);CHKERRQ(ierr);

  /* initialize factinfo */
  factinfo.shiftnz   = 0.0;
  factinfo.shiftpd   = 0.0; /* false */
  factinfo.zeropivot = 1.e-12;
  if (TestShift == 1){
    factinfo.shiftnz = 0.1;
  } else if (TestShift == 2){
    factinfo.shiftpd = 1.0; /* true*/
  }
  
  /* Test MatCholeskyFactor(), MatICCFactor() */
  /*------------------------------------------*/
  /* Test aij matrix A */
  if (TestAIJ){
    if (displ>0){ierr = PetscPrintf(PETSC_COMM_SELF,"AIJ: \n");}
    i = 0;
    for (lvl=-1; lvl<10; lvl++){ 
      if (lvl==-1) {  /* Cholesky factor */
        factinfo.fill = 5.0;
        ierr = MatCholeskyFactorSymbolic(A,perm,&factinfo,&sC);CHKERRQ(ierr);
      } else {       /* incomplete Cholesky factor */
        factinfo.fill   = 5.0;
        factinfo.levels = lvl;
        ierr = MatICCFactorSymbolic(A,perm,&factinfo,&sC);CHKERRQ(ierr);
      }      
      ierr = MatCholeskyFactorNumeric(A,&factinfo,&sC);CHKERRQ(ierr);  

      ierr = MatMult(A,x,b);CHKERRQ(ierr);
      ierr = MatSolve(sC,b,y);CHKERRQ(ierr); 
      ierr = MatDestroy(sC);CHKERRQ(ierr);

      /* Check the error */
      ierr = VecAXPY(y,neg_one,x);CHKERRQ(ierr);
      ierr = VecNorm(y,NORM_2,&norm2);CHKERRQ(ierr);
      if (displ>0){ierr = PetscPrintf(PETSC_COMM_SELF,"  lvl: %d, error: %G\n", lvl,norm2);}
      err[i++] = norm2;
    } 
  } 
  
  /* Test baij matrix A */
  if (TestBAIJ){
    if (displ>0){ierr = PetscPrintf(PETSC_COMM_SELF,"BAIJ: \n");}
    i = 0;
    for (lvl=-1; lvl<10; lvl++){
      if (lvl==-1) {  /* Cholesky factor */
        factinfo.fill = 5.0;
        ierr = MatCholeskyFactorSymbolic(A,perm,&factinfo,&sC);CHKERRQ(ierr);
      } else {       /* incomplete Cholesky factor */
        factinfo.fill   = 5.0;
        factinfo.levels = lvl;
        ierr = MatICCFactorSymbolic(A,perm,&factinfo,&sC);CHKERRQ(ierr);
      }      
      ierr = MatCholeskyFactorNumeric(A,&factinfo,&sC);CHKERRQ(ierr);  

      ierr = MatMult(A,x,b);CHKERRQ(ierr); 
      ierr = MatSolve(sC,b,y);CHKERRQ(ierr); 
      ierr = MatDestroy(sC);CHKERRQ(ierr);

      /* Check the error */
      ierr = VecAXPY(y,neg_one,x);CHKERRQ(ierr);
      ierr = VecNorm(y,NORM_2,&norm2);CHKERRQ(ierr);
      if (displ>0){ierr = PetscPrintf(PETSC_COMM_SELF,"  lvl: %d, error: %G\n", lvl,norm2);}
      err[i++] = norm2;
    } 
  }

  /* Test sbaij matrix sA */
  if (displ>0){ierr = PetscPrintf(PETSC_COMM_SELF,"SBAIJ: \n");}
  i = 0;
  for (lvl=-1; lvl<10; lvl++){ 
    if (lvl==-1) {  /* Cholesky factor */
      factinfo.fill = 5.0;
      ierr = MatCholeskyFactorSymbolic(sA,perm,&factinfo,&sC);CHKERRQ(ierr);
    } else {       /* incomplete Cholesky factor */
      factinfo.fill   = 5.0;
      factinfo.levels = lvl;
      ierr = MatICCFactorSymbolic(sA,perm,&factinfo,&sC);CHKERRQ(ierr);
    }      
    ierr = MatCholeskyFactorNumeric(sA,&factinfo,&sC);CHKERRQ(ierr);  

    if (lvl==0 && bs==1){ /* Test inplace ICC(0) for sbaij sA */
        Mat B;
        ierr = MatDuplicate(sA,MAT_COPY_VALUES,&B);CHKERRQ(ierr);
        ierr = MatICCFactor(B,perm,&factinfo);CHKERRQ(ierr);
        ierr = MatEqual(sC,B,&equal);CHKERRQ(ierr);
        if (!equal){
          SETERRQ(PETSC_ERR_USER,"in-place Cholesky factor != out-place Cholesky factor");
        }
        ierr = MatDestroy(B);CHKERRQ(ierr);
    }

    ierr = MatMult(sA,x,b);CHKERRQ(ierr);
    ierr = MatSolve(sC,b,y);CHKERRQ(ierr); 

    /* Test MatSolves() */
    if (bs == 1) {
      Vecs xx,bb;
      ierr = VecsCreateSeq(PETSC_COMM_SELF,n,4,&xx);CHKERRQ(ierr);
      ierr = VecsDuplicate(xx,&bb);CHKERRQ(ierr);
      ierr = MatSolves(sC,bb,xx);CHKERRQ(ierr); 
      ierr = VecsDestroy(xx);CHKERRQ(ierr); 
      ierr = VecsDestroy(bb);CHKERRQ(ierr); 
    }
    ierr = MatDestroy(sC);CHKERRQ(ierr);

    /* Check the error */
    ierr = VecAXPY(y,neg_one,x);CHKERRQ(ierr);
    ierr = VecNorm(y,NORM_2,&norm2);CHKERRQ(ierr);
    if (displ>0){ierr = PetscPrintf(PETSC_COMM_SELF,"  lvl: %d, error: %G\n", lvl,norm2); }
    err[i] -= norm2;
    if (err[i] > tol) SETERRQ2(PETSC_ERR_USER," level: %d, err: %G\n", lvl,err[i]); 
  } 

  ierr = ISDestroy(perm);CHKERRQ(ierr);
  ierr = MatDestroy(A);CHKERRQ(ierr);
  ierr = MatDestroy(sA);CHKERRQ(ierr);
  ierr = VecDestroy(x);CHKERRQ(ierr);
  ierr = VecDestroy(y);CHKERRQ(ierr);  
  ierr = VecDestroy(b);CHKERRQ(ierr);
  ierr = PetscRandomDestroy(rdm);CHKERRQ(ierr);

  ierr = PetscFinalize();CHKERRQ(ierr);
  return 0;
}