mexsparchol.c

凸优化程序包

  *pnadd = nadd;
  return ix;
}

/* ============================================================
   MAIN: MEXFUNCTION
   ============================================================ */
/* ************************************************************
   PROCEDURE mexFunction - Entry for Matlab
   ************************************************************ */
void mexFunction(const int nlhs, mxArray *plhs[],
  const int nrhs, const mxArray *prhs[])
{
  const mxArray *L_FIELD;
  mxArray *myplhs[NPAROUT];
  int    m, i, j, inz, iwsiz, nsuper, tmpsiz, fwsiz, nskip, nadd, m1;
  double *fwork, *d, *skipPr, *orgd;
  const double *permPr,*xsuperPr,*Ppr,*absd;
  int    *perm, *snode, *xsuper, *iwork, *xlindx, *skip, *skipJc;
  const int *LINir, *Pjc, *Pir;
  double canceltol, maxu, abstol;
  jcir   L;
  char useAbsd, useDelay;
/* ------------------------------------------------------------
   Check for proper number of arguments
   blkchol(L,P, pars,absd) with nparinmin=2.
   ------------------------------------------------------------ */
  if(nrhs < NPARINMIN)
    mexErrMsgTxt("blkchol requires more input arguments");
  if(nlhs > NPAROUT)
    mexErrMsgTxt("blkchol produces less output arguments");
/* ------------------------------------------------------------
   Get input matrix P to be factored.
   ------------------------------------------------------------ */
  if( (m = mxGetM(P_IN)) != mxGetN(P_IN))
    mexErrMsgTxt("P must be square");
  if(!mxIsSparse(P_IN))
    mexErrMsgTxt("P must be sparse");
  Pjc    = mxGetJc(P_IN);
  Pir    = mxGetIr(P_IN);
  Ppr    = mxGetPr(P_IN);
/* ------------------------------------------------------------
   Disassemble block Cholesky structure L
   ------------------------------------------------------------ */
  if(!mxIsStruct(L_IN))
    mexErrMsgTxt("Parameter `L' should be a structure.");
  if( (L_FIELD = mxGetField(L_IN,0,"perm")) == NULL)        /* L.perm */
    mexErrMsgTxt("Missing field L.perm.");
  if(m != mxGetM(L_FIELD) * mxGetN(L_FIELD))
    mexErrMsgTxt("perm size mismatch");
  permPr = mxGetPr(L_FIELD);
  if( (L_FIELD = mxGetField(L_IN,0,"L")) == NULL)           /* L.L */
    mexErrMsgTxt("Missing field L.L.");
  if( m != mxGetM(L_FIELD) || m != mxGetN(L_FIELD) )
    mexErrMsgTxt("Size L.L mismatch.");
  if(!mxIsSparse(L_FIELD))
    mexErrMsgTxt("L.L should be sparse.");
  L.jc = mxGetJc(L_FIELD);
  LINir = mxGetIr(L_FIELD);
  if( (L_FIELD = mxGetField(L_IN,0,"xsuper")) == NULL)      /* L.xsuper */
    mexErrMsgTxt("Missing field L.xsuper.");
  nsuper = mxGetM(L_FIELD) * mxGetN(L_FIELD) - 1;
  if( nsuper > m )
    mexErrMsgTxt("Size L.xsuper mismatch.");
  xsuperPr = mxGetPr(L_FIELD);
  if( (L_FIELD = mxGetField(L_IN,0,"tmpsiz")) == NULL)      /* L.tmpsiz */
    mexErrMsgTxt("Missing field L.tmpsiz.");
  tmpsiz   = mxGetScalar(L_FIELD);
/* ------------------------------------------------------------
   Disassemble pars structure: canceltol, maxu
   ------------------------------------------------------------ */
  canceltol = 1E-15;           /* supply with defaults */
  maxu = 5E5;
  abstol = 1E-20;
  useAbsd = 0;
  useDelay = 0;
  if(nrhs >= NPARINMIN + 1){       /* 3rd argument = pars */
    if(!mxIsStruct(PARS_IN))
      mexErrMsgTxt("Parameter `pars' should be a structure.");
    if( (L_FIELD = mxGetField(PARS_IN,0,"canceltol")) != NULL)
      canceltol  = mxGetScalar(L_FIELD);  /* pars.canceltol */
    if( (L_FIELD = mxGetField(PARS_IN,0,"maxu")) != NULL)
      maxu = mxGetScalar(L_FIELD);  /* pars.maxu */
    if( (L_FIELD = mxGetField(PARS_IN,0,"abstol")) != NULL){
      abstol = mxGetScalar(L_FIELD);  /* pars.abstol */
      abstol = MAX(abstol, 0.0);
    }
    if( (L_FIELD = mxGetField(PARS_IN,0,"delay")) != NULL)
      useDelay = mxGetScalar(L_FIELD);  /* pars.delay */
/* ------------------------------------------------------------
   Get optional vector absd
   ------------------------------------------------------------ */
    if(nrhs >= NPARIN){
      useAbsd = 1;
      absd = mxGetPr(ABSD_IN);
      if(m != mxGetM(ABSD_IN) * mxGetN(ABSD_IN))
        mexErrMsgTxt("absd size mismatch");
    }
  }
/* ------------------------------------------------------------
   Create sparse output matrix L(m x m).
   ------------------------------------------------------------ */
  L_OUT = mxCreateSparse(m,m, L.jc[m],mxREAL);
  L.ir  = mxGetIr(L_OUT);
  L.pr  = mxGetPr(L_OUT);
  memcpy(mxGetJc(L_OUT), L.jc, (m+1) * sizeof(int));
  memcpy(L.ir, LINir, L.jc[m] * sizeof(int));
/* ------------------------------------------------------------
   Create ouput vector d(m).
   ------------------------------------------------------------ */
  D_OUT = mxCreateDoubleMatrix(m,1,mxREAL);
  d     = mxGetPr(D_OUT);
/* ------------------------------------------------------------
   Compute required sizes of working arrays:
   iwsiz = 2*(m + nsuper).
   fwsiz = tmpsiz.
   ------------------------------------------------------------ */
  iwsiz = MAX(2*(m+nsuper), 1);
  fwsiz = MAX(tmpsiz, 1);
/* ------------------------------------------------------------
   Allocate working arrays:
   integer: perm(m), snode(m), xsuper(nsuper+1),
      iwork(iwsiz), xlindx(m+1), skip(m),
   double: orgd(m), fwork(fwsiz).
   ------------------------------------------------------------ */
  m1 = MAX(m,1);                  /* avoid alloc to 0 */
  perm      = (int *) mxCalloc(m1,sizeof(int)); 
  snode     = (int *) mxCalloc(m1,sizeof(int)); 
  xsuper    = (int *) mxCalloc(nsuper+1,sizeof(int));
  iwork     = (int *) mxCalloc(iwsiz,sizeof(int));
  xlindx    = (int *) mxCalloc(m+1,sizeof(int));
  skip      = (int *) mxCalloc(m1, sizeof(int));
  orgd    = (double *) mxCalloc(m1,sizeof(double)); 
  fwork   = (double *) mxCalloc(fwsiz,sizeof(double)); 
/* ------------------------------------------------------------
   Convert PERM, XSUPER to integer and C-Style
   ------------------------------------------------------------ */
  for(i = 0; i < m; i++){
    j = permPr[i];
    perm[i] = --j;
  }
  for(i = 0; i <= nsuper; i++){
    j =  xsuperPr[i];
    xsuper[i] = --j;
  }
/* ------------------------------------------------------------
   Let L = tril(P(PERM,PERM)), uses orgd(m) as temp working storage.
   ------------------------------------------------------------ */
  permuteP(L.jc,L.ir,L.pr, Pjc,Pir,Ppr, perm, orgd, m);
/* ------------------------------------------------------------
   If no orgd has been supplied, take orgd = diag(L on input)
   Otherwise, let orgd = absd(perm).
   ------------------------------------------------------------ */
  if(useAbsd)
    for(j = 0; j < m; j++)
      orgd[j] = absd[perm[j]];
  else
    for(j = 0; j < m; j++)
      orgd[j] = L.pr[L.jc[j]];
/* ------------------------------------------------------------
   Create "snode" and "xlindx"; change L.ir to the compact subscript
   array (with xlindx), and do BLOCK SPARSE CHOLESKY.
   ------------------------------------------------------------ */
  nskip = spchol(m, nsuper, xsuper, snode, xlindx,
                 L.ir, orgd, L.jc, L.pr, d, perm, abstol,
                 canceltol, maxu, skip, &nadd, iwsiz, iwork, fwsiz, fwork);
  if(nskip < 0)
    mexErrMsgTxt("Insufficient workspace in pblkchol");
/* ------------------------------------------------------------
   Copy original row-indices from LINir to L.ir.
   ------------------------------------------------------------ */
  memcpy(L.ir, LINir, L.jc[m] * sizeof(int));
/* ------------------------------------------------------------
   Create output matrices skip = sparse([],[],[],m,1,nskip),
   diagadd = sparse([],[],[],m,1,nadd),
   ------------------------------------------------------------ */
  SKIP_OUT = mxCreateSparse(m,1, MAX(1,nskip),mxREAL);
  memcpy(mxGetIr(SKIP_OUT), skip, nskip * sizeof(int));
  skipJc = mxGetJc(SKIP_OUT);
  skipJc[0] = 0; skipJc[1] = nskip;
  skipPr   = mxGetPr(SKIP_OUT);
/* ------------------------------------------------------------
   useDelay = 1 then L(:,i) is i-th column before ith pivot; useful
     for pivot-delaying strategy. (Fwslv(L, L(:,i)) still required.)
   ------------------------------------------------------------ */
  if(useDelay == 1)
    for(j = 0; j < nskip; j++)
      skipPr[j] = 1.0;
  else
    for(j = 0; j < nskip; j++){
      i = skip[j];
      skipPr[j] = L.pr[L.jc[i]];             /* Set skipped l(:,i)=ei. */
      L.pr[L.jc[i]] = 1.0;
      fzeros(L.pr+L.jc[i]+1,L.jc[i+1]-L.jc[i]-1);
    }
  DIAGADD_OUT = mxCreateSparse(m,1, MAX(1,nadd),mxREAL);
  memcpy(mxGetIr(DIAGADD_OUT), iwork, nadd * sizeof(int));
  skipJc = mxGetJc(DIAGADD_OUT);
  skipJc[0] = 0; skipJc[1] = nadd;
  skipPr   = mxGetPr(DIAGADD_OUT);
  for(j = 0; j < nadd; j++)
    skipPr[j] = orgd[iwork[j]];
/* ------------------------------------------------------------
   Release working arrays.
   ------------------------------------------------------------ */
  mxFree(fwork);
  mxFree(orgd);
  mxFree(skip);
  mxFree(xlindx);
  mxFree(iwork);
  mxFree(xsuper);
  mxFree(snode);
  mxFree(perm);
/* ------------------------------------------------------------
   Copy requested output parameters (at least 1), release others.
   ------------------------------------------------------------ */
  i = MAX(nlhs, 1);
  memcpy(plhs,myplhs, i * sizeof(mxArray *));
  for(; i < NPAROUT; i++)
    mxDestroyArray(myplhs[i]);
}