Exemplo n.º 1
0
void undoscale(lprec *lp)
{
  int     i, j, nz;
  MATrec  *mat = lp->matA;
  REAL    *value;
  int     *rownr, *colnr;

  if(lp->scaling_used) {

    /* Unscale the OF */
    for(j = 1; j <= lp->columns; j++) {
      lp->orig_obj[j] = unscaled_mat(lp, lp->orig_obj[j], 0, j);
    }

    /* Unscale the matrix */
    mat_validate(mat);
    nz = get_nonzeros(lp);
    value = &(COL_MAT_VALUE(0));
    rownr = &(COL_MAT_ROWNR(0));
    colnr = &(COL_MAT_COLNR(0));
    for(j = 0; j < nz;
        j++, value += matValueStep, rownr += matRowColStep, colnr += matRowColStep) {
      *value = unscaled_mat(lp, *value, *rownr, *colnr);
    }

    /* Unscale variable bounds */
    for(i = lp->rows + 1, j = 1; i <= lp->sum; i++, j++) {
      lp->orig_lowbo[i] = unscaled_value(lp, lp->orig_lowbo[i], i);
      lp->orig_upbo[i]  = unscaled_value(lp, lp->orig_upbo[i], i);
      lp->sc_lobound[j]  = unscaled_value(lp, lp->sc_lobound[j], i);
    }

    /* Unscale the rhs, upper and lower bounds... */
    for(i = 0; i <= lp->rows; i++) {
      lp->orig_rhs[i] = unscaled_value(lp, lp->orig_rhs[i], i);
      j = lp->presolve_undo->var_to_orig[i];
      if(j != 0)
        lp->presolve_undo->fixed_rhs[j] = unscaled_value(lp, lp->presolve_undo->fixed_rhs[j], i);
      lp->orig_lowbo[i] = unscaled_value(lp, lp->orig_lowbo[i], i);
      lp->orig_upbo[i] = unscaled_value(lp, lp->orig_upbo[i], i);
    }

    FREE(lp->scalars);
    lp->scaling_used = FALSE;
    lp->columns_scaled = FALSE;

    set_action(&lp->spx_action, ACTION_REBASE | ACTION_REINVERT | ACTION_RECOMPUTE);
  }
}
Exemplo n.º 2
0
STATIC MYBOOL scale_columns(lprec *lp, REAL *scaledelta)
{
  int     i,j, colMax, nz;
  REAL    *scalechange;
  REAL    *value;
  int     *colnr;
  MATrec  *mat = lp->matA;

  /* Check that columns are in fact targeted */
  if((lp->scalemode & SCALE_ROWSONLY) != 0)
    return( TRUE );

  if(scaledelta == NULL)
    scalechange = &lp->scalars[lp->rows];
  else
    scalechange = &scaledelta[lp->rows];

  colMax = lp->columns;

  /* Scale matrix entries (including any Lagrangean constraints) */
  for(i = 1; i <= lp->columns; i++) {
    lp->orig_obj[i] *= scalechange[i];
  }

  mat_validate(lp->matA);
  nz = get_nonzeros(lp);
  value = &(COL_MAT_VALUE(0));
  colnr = &(COL_MAT_COLNR(0));
  for(i = 0; i < nz;
      i++, value += matValueStep, colnr += matRowColStep) {
    (*value) *= scalechange[*colnr];
  }

  /* Scale variable bounds as well */
  for(i = 1, j = lp->rows + 1; j <= lp->sum; i++, j++) {
    if(lp->orig_lowbo[j] > -lp->infinite)
      lp->orig_lowbo[j] /= scalechange[i];
    if(lp->orig_upbo[j] < lp->infinite)
      lp->orig_upbo[j] /= scalechange[i];
    if(lp->sc_lobound[i] != 0)
      lp->sc_lobound[i] /= scalechange[i];
  }

  lp->columns_scaled = TRUE;
  set_action(&lp->spx_action, ACTION_REBASE | ACTION_REINVERT | ACTION_RECOMPUTE);

  return( TRUE );
}
Exemplo n.º 3
0
STATIC void unscale_columns(lprec *lp)
{
  int     i, j, nz;
  MATrec  *mat = lp->matA;
  REAL    *value;
  int     *rownr, *colnr;

  if(!lp->columns_scaled)
    return;

  /* Unscale OF */
  for(j = 1; j <= lp->columns; j++) {
    lp->orig_obj[j] = unscaled_mat(lp, lp->orig_obj[j], 0, j);
  }

  /* Unscale mat */
  mat_validate(mat);
  nz = get_nonzeros(lp);
  value = &(COL_MAT_VALUE(0));
  rownr = &(COL_MAT_ROWNR(0));
  colnr = &(COL_MAT_COLNR(0));
  for(j = 0; j < nz;
      j++, value += matValueStep, rownr += matRowColStep, colnr += matRowColStep) {
    *value = unscaled_mat(lp, *value, *rownr, *colnr);
  }

  /* Unscale bounds as well */
  for(i = lp->rows + 1, j = 1; i <= lp->sum; i++, j++) {
    lp->orig_lowbo[i] = unscaled_value(lp, lp->orig_lowbo[i], i);
    lp->orig_upbo[i]  = unscaled_value(lp, lp->orig_upbo[i], i);
    lp->sc_lobound[j]  = unscaled_value(lp, lp->sc_lobound[j], i);
  }

  for(i = lp->rows + 1; i<= lp->sum; i++)
    lp->scalars[i] = 1;

  lp->columns_scaled = FALSE;
  set_action(&lp->spx_action, ACTION_REBASE | ACTION_REINVERT | ACTION_RECOMPUTE);
}
Exemplo n.º 4
0
/* Compute the scale factor by the formulae:
      FALSE: SUM (log |Aij|) ^ 2
      TRUE:  SUM (log |Aij| - RowScale[i] - ColScale[j]) ^ 2 */
REAL CurtisReidMeasure(lprec *lp, MYBOOL _Advanced, REAL *FRowScale, REAL *FColScale)
{
  int      i, nz;
  REAL     absvalue, logvalue;
  register REAL result;
  MATrec   *mat = lp->matA;
  REAL     *value;
  int      *rownr, *colnr;

  /* Do OF part */
  result = 0;
  for(i = 1; i <= lp->columns; i++) {
    absvalue = fabs(lp->orig_obj[i]);
    if(absvalue > 0) {
      logvalue = log(absvalue);
      if(_Advanced)
        logvalue -= FRowScale[0] + FColScale[i];
      result += logvalue*logvalue;
    }
  }

  /* Do constraint matrix part */
  mat_validate(mat);
  value = &(COL_MAT_VALUE(0));
  rownr = &(COL_MAT_ROWNR(0));
  colnr = &(COL_MAT_COLNR(0));
  nz = get_nonzeros(lp);
  for(i = 0; i < nz;
      i++, value += matValueStep, rownr += matRowColStep, colnr += matRowColStep) {
    absvalue = fabs(*value);
    if(absvalue > 0) {
      logvalue = log(absvalue);
      if(_Advanced)
        logvalue -= FRowScale[*rownr] + FColScale[*colnr];
      result += logvalue*logvalue;
    }
  }
  return( result );
}
Exemplo n.º 5
0
/* List the current user data matrix columns over the selected row range */
void blockWriteAMAT(FILE *output, const char *label, lprec* lp, int first, int last)
{
  int    i, j, k = 0;
  int    nzb, nze, jb;
  double hold;
  MATrec *mat = lp->matA;

  if(!mat_validate(mat))
    return;
  if(first < 0)
    first = 0;
  if(last < 0)
    last = lp->rows;

  fprintf(output, "%s", label);
  fprintf(output, "\n");

  if(first == 0) {
    for(j = 1; j <= lp->columns; j++) {
      hold = get_mat(lp, 0, j);
      fprintf(output, " %18g", hold);
      k++;
      if(my_mod(k, 4) == 0) {
        fprintf(output, "\n");
        k = 0;
      }
    }
    if(my_mod(k, 4) != 0) {
      fprintf(output, "\n");
      k = 0;
    }
    first++;
  }
  nze = mat->row_end[first-1];
  for(i = first; i <= last; i++) {
    nzb = nze;
    nze = mat->row_end[i];
    if(nzb >= nze)
      jb = lp->columns+1;
    else
      jb = ROW_MAT_COLNR(nzb);
    for(j = 1; j <= lp->columns; j++) {
      if(j < jb)
        hold = 0;
      else {
        hold = get_mat(lp, i, j);
        nzb++;
        if(nzb < nze)
          jb = ROW_MAT_COLNR(nzb);
        else
          jb = lp->columns+1;
      }
      fprintf(output, " %18g", hold);
      k++;
      if(my_mod(k, 4) == 0) {
        fprintf(output, "\n");
        k = 0;
      }
    }
    if(my_mod(k, 4) != 0) {
      fprintf(output, "\n");
      k = 0;
    }
  }
  if(my_mod(k, 4) != 0)
    fprintf(output, "\n");
}
Exemplo n.º 6
0
MYBOOL __WINAPI write_lpex(lprec *lp, void *userhandle, write_modeldata_func write_modeldata)
{
  int    i, j, b,
         nrows = lp->rows,
         ncols = lp->columns,
         nchars, maxlen = LP_MAXLINELEN;
  MYBOOL ok;
  REAL   a;
  char   *ptr;

  if(lp->matA->is_roworder) {
    report(lp, IMPORTANT, "LP_writefile: Cannot write to LP file while in row entry mode.\n");
    return(FALSE);
  }
  if(!mat_validate(lp->matA)) {
    report(lp, IMPORTANT, "LP_writefile: Could not validate the data matrix.\n");
    return(FALSE);
  }

  /* Write name of model */
  ptr = get_lp_name(lp);
  if(ptr != NULL)
    if(*ptr)
      write_lpcomment(userhandle, write_modeldata, ptr, FALSE);
    else
      ptr = NULL;

  /* Write the objective function */
  write_lpcomment(userhandle, write_modeldata, "Objective function", (MYBOOL) (ptr != NULL));
  if(is_maxim(lp))
    write_data(userhandle, write_modeldata, "max: ");
  else
    write_data(userhandle, write_modeldata, "min: ");

  write_lprow(lp, 0, userhandle, write_modeldata, maxlen);
  a = get_rh(lp, 0);
  if(a != 0)
    write_data(userhandle, write_modeldata, " %+.12g", a);
  write_data(userhandle, write_modeldata, ";\n");

  /* Write constraints */
  if(nrows > 0)
    write_lpcomment(userhandle, write_modeldata, "Constraints", TRUE);
  for(j = 1; j <= nrows; j++) {
    if(((lp->names_used) && (lp->row_name[j] != NULL)) || (write_lprow(lp, j, userhandle, NULL, maxlen) == 1))
      ptr = get_row_name(lp, j);
    else
      ptr = NULL;
    if((ptr != NULL) && (*ptr))
      write_data(userhandle, write_modeldata, "%s: ", ptr);

#ifndef SingleBoundedRowInLP
    /* Write the ranged part of the constraint, if specified */
    if ((lp->orig_upbo[j]) && (lp->orig_upbo[j] < lp->infinite)) {
      if(my_chsign(is_chsign(lp, j), lp->orig_rhs[j]) == -lp->infinite)
        write_data(userhandle, write_modeldata, "-Inf %s ", (is_chsign(lp, j)) ? ">=" : "<=");
      else if(my_chsign(is_chsign(lp, j), lp->orig_rhs[j]) == lp->infinite)
        write_data(userhandle, write_modeldata, "+Inf %s ", (is_chsign(lp, j)) ? ">=" : "<=");
      else
        write_data(userhandle, write_modeldata, "%+.12g %s ",
                (lp->orig_upbo[j]-lp->orig_rhs[j]) * (is_chsign(lp, j) ? 1.0 : -1.0) / (lp->scaling_used ? lp->scalars[j] : 1.0),
                (is_chsign(lp, j)) ? ">=" : "<=");
    }
#endif

    if((!write_lprow(lp, j, userhandle, write_modeldata, maxlen)) && (ncols >= 1))
      write_data(userhandle, write_modeldata, "0 %s", get_col_name(lp, 1));

    if(lp->orig_upbo[j] == 0)
      write_data(userhandle, write_modeldata, " =");
    else if(is_chsign(lp, j))
      write_data(userhandle, write_modeldata, " >=");
    else
      write_data(userhandle, write_modeldata, " <=");
    if(fabs(get_rh(lp, j) + lp->infinite) < 1)
      write_data(userhandle, write_modeldata, " -Inf;\n");
    else if(fabs(get_rh(lp, j) - lp->infinite) < 1)
      write_data(userhandle, write_modeldata, " +Inf;\n");
    else
      write_data(userhandle, write_modeldata, " %.12g;\n", get_rh(lp, j));

#ifdef SingleBoundedRowInLP
    /* Write the ranged part of the constraint, if specified */
    if ((lp->orig_upbo[j]) && (lp->orig_upbo[j] < lp->infinite)) {
      if(((lp->names_used) && (lp->row_name[j] != NULL)) || (write_lprow(lp, j, userhandle, NULL, maxlen) == 1))
        ptr = get_row_name(lp, j);
      else
        ptr = NULL;
      if((ptr != NULL) && (*ptr))
        write_data(userhandle, write_modeldata, "%s: ", ptr);
      if((!write_lprow(lp, j, userhandle, write_modeldata, maxlen)) && (get_Ncolumns(lp) >= 1))
        write_data(userhandle, write_modeldata, "0 %s", get_col_name(lp, 1));
      write_data(userhandle, write_modeldata, " %s %g;\n",
                     (is_chsign(lp, j)) ? "<=" : ">=",
                     (lp->orig_upbo[j]-lp->orig_rhs[j]) * (is_chsign(lp, j) ? 1.0 : -1.0) / (lp->scaling_used ? lp->scalars[j] : 1.0));
    }
#endif
  }

  /* Write bounds on variables */
  ok = FALSE;
  for(i = nrows + 1; i <= lp->sum; i++)
    if(!is_splitvar(lp, i - nrows)) {
      if(lp->orig_lowbo[i] == lp->orig_upbo[i]) {
        if(!ok) {
	  write_lpcomment(userhandle, write_modeldata, "Variable bounds", TRUE);
	  ok = TRUE;
	}
        write_data(userhandle, write_modeldata, "%s = %.12g;\n", get_col_name(lp, i - nrows), get_upbo(lp, i - nrows));
      }
      else {
#ifndef SingleBoundedRowInLP
        if((lp->orig_lowbo[i] != 0) && (lp->orig_upbo[i] < lp->infinite)) {
          if(!ok) {
	    write_lpcomment(userhandle, write_modeldata, "Variable bounds", TRUE);
	    ok = TRUE;
	  }
          if(lp->orig_lowbo[i] == -lp->infinite)
            write_data(userhandle, write_modeldata, "-Inf");
          else
            write_data(userhandle, write_modeldata, "%.12g", get_lowbo(lp, i - nrows));
          write_data(userhandle, write_modeldata, " <= %s <= ", get_col_name(lp, i - nrows));
          if(lp->orig_lowbo[i] == lp->infinite)
            write_data(userhandle, write_modeldata, "+Inf");
          else
            write_data(userhandle, write_modeldata, "%.12g", get_upbo(lp, i - nrows));
          write_data(userhandle, write_modeldata, ";\n");
	}
        else
#endif
        {
          if(lp->orig_lowbo[i] != 0) {
            if(!ok) {
	      write_lpcomment(userhandle, write_modeldata, "Variable bounds", TRUE);
	      ok = TRUE;
	    }
      	    if(lp->orig_lowbo[i] == -lp->infinite)
	      write_data(userhandle, write_modeldata, "%s >= -Inf;\n", get_col_name(lp, i - nrows));
      	    else if(lp->orig_lowbo[i] == lp->infinite)
	      write_data(userhandle, write_modeldata, "%s >= +Inf;\n", get_col_name(lp, i - nrows));
	    else
              write_data(userhandle, write_modeldata, "%s >= %.12g;\n",
                              get_col_name(lp, i - nrows), get_lowbo(lp, i - nrows));
	  }
	  if(lp->orig_upbo[i] != lp->infinite) {
            if(!ok) {
	      write_lpcomment(userhandle, write_modeldata, "Variable bounds", TRUE);
	      ok = TRUE;
	    }
            write_data(userhandle, write_modeldata, "%s <= %.12g;\n",
                            get_col_name(lp, i - nrows), get_upbo(lp, i - nrows));
	  }
        }
      }
    }

  /* Write optional integer section */
  if(lp->int_vars > 0) {
    write_lpcomment(userhandle, write_modeldata, "Integer definitions", TRUE);
    i = 1;
    while((i <= ncols) && !is_int(lp, i))
      i++;
    if(i <= ncols) {
      nchars = write_data(userhandle, write_modeldata, "int %s", get_col_name(lp, i));
      i++;
      for(; i <= ncols; i++)
        if((!is_splitvar(lp, i)) && (is_int(lp, i))) {
          if((maxlen!= 0) && (nchars > maxlen)) {
            write_data(userhandle, write_modeldata, "%s", "\n");
            nchars = 0;
          }
          write_data(userhandle, write_modeldata, ",%s", get_col_name(lp, i));
        }
      write_data(userhandle, write_modeldata, ";\n");
    }
  }

  /* Write optional SEC section */
  if(lp->sc_vars > 0) {
    write_lpcomment(userhandle, write_modeldata, "Semi-continuous variables", TRUE);
    i = 1;
    while((i <= ncols) && !is_semicont(lp, i))
      i++;
    if(i <= ncols) {
      nchars = write_data(userhandle, write_modeldata, "sec %s", get_col_name(lp, i));
      i++;
      for(; i <= ncols; i++)
        if((!is_splitvar(lp, i)) && (is_semicont(lp, i))) {
          if((maxlen != 0) && (nchars > maxlen)) {
            write_data(userhandle, write_modeldata, "%s", "\n");
            nchars = 0;
          }
          nchars += write_data(userhandle, write_modeldata, ",%s", get_col_name(lp, i));
        }
      write_data(userhandle, write_modeldata, ";\n");
    }
  }

  /* Write optional SOS section */
  if(SOS_count(lp) > 0) {
    SOSgroup *SOS = lp->SOS;
    write_lpcomment(userhandle, write_modeldata, "SOS definitions", TRUE);
    write_data(userhandle, write_modeldata, "SOS\n");
    for(b = 0, i = 0; i < SOS->sos_count; b = SOS->sos_list[i]->priority, i++) {
      nchars = write_data(userhandle, write_modeldata, "%s: ",
              (SOS->sos_list[i]->name == NULL) ||
              (*SOS->sos_list[i]->name==0) ? "SOS" : SOS->sos_list[i]->name); /* formatnumber12((double) lp->sos_list[i]->priority) */

      for(a = 0.0, j = 1; j <= SOS->sos_list[i]->size; a = SOS->sos_list[i]->weights[j], j++) {
        if((maxlen != 0) && (nchars > maxlen)) {
          write_data(userhandle, write_modeldata, "%s", "\n");
          nchars = 0;
        }
        if(SOS->sos_list[i]->weights[j] == ++a)
          nchars += write_data(userhandle, write_modeldata, "%s%s",
                  (j > 1) ? "," : "",
                  get_col_name(lp, SOS->sos_list[i]->members[j]));
        else
          nchars += write_data(userhandle, write_modeldata, "%s%s:%.12g",
                  (j > 1) ? "," : "",
                  get_col_name(lp, SOS->sos_list[i]->members[j]),
		  SOS->sos_list[i]->weights[j]);
      }
      if(SOS->sos_list[i]->priority == ++b)
        nchars += write_data(userhandle, write_modeldata, " <= %d;\n", SOS->sos_list[i]->type);
      else
        nchars += write_data(userhandle, write_modeldata, " <= %d:%d;\n", SOS->sos_list[i]->type, SOS->sos_list[i]->priority);
    }
  }

  ok = TRUE;

  return(ok);
}
Exemplo n.º 7
0
MYBOOL __WINAPI guess_basis(lprec *lp, REAL *guessvector, int *basisvector)
{
  MYBOOL *isnz = NULL, status = FALSE;
  REAL   *values = NULL, *violation = NULL,
         eps = lp->epsprimal,
         *value, error, upB, loB, sortorder = -1.0;
  int    i, j, jj, n, *rownr, *colnr, *slkpos = NULL,
         nrows = lp->rows, ncols = lp->columns, nsum = lp->sum;
  int    *basisnr;
  MATrec *mat = lp->matA;

  if(!mat_validate(mat))
    return( status );

  /* Create helper arrays, providing for multiple use of the violation array */
  if(!allocREAL(lp, &values, nsum+1, TRUE) ||
     !allocREAL(lp, &violation, nsum+1, TRUE))
    goto Finish;

  /* Compute the values of the constraints for the given guess vector */
  i = 0;
  n = get_nonzeros(lp);
  rownr = &COL_MAT_ROWNR(i);
  colnr = &COL_MAT_COLNR(i);
  value = &COL_MAT_VALUE(i);
  for(; i < n; i++, rownr += matRowColStep, colnr += matRowColStep, value += matValueStep)
    values[*rownr] += unscaled_mat(lp, my_chsign(is_chsign(lp, *rownr), *value), *rownr, *colnr) *
                      guessvector[*colnr];
  MEMMOVE(values+nrows+1, guessvector+1, ncols);

  /* Initialize bound "violation" or primal non-degeneracy measures, expressed
     as the absolute value of the differences from the closest bound. */
  for(i = 1; i <= nsum; i++) {
    if(i <= nrows) {
      loB = get_rh_lower(lp, i);
      upB = get_rh_upper(lp, i);
    }
    else {
      loB = get_lowbo(lp, i-nrows);
      upB = get_upbo(lp, i-nrows);
    }

    /* Free constraints/variables */
    if(my_infinite(lp, loB) && my_infinite(lp, upB))
      error = 0;
    /* Violated constraints/variable bounds */
    else if(values[i]+eps < loB)
      error = loB-values[i];
    else if(values[i]-eps > upB)
      error = values[i]-upB;
    /* Non-violated constraints/variables bounds */
    else if(my_infinite(lp, upB))
      error = MAX(0, values[i]-loB);
    else if(my_infinite(lp, loB))
      error = MAX(0, upB-values[i]);
    else
      error = MIN(upB-values[i], values[i]-loB); /* MAX(upB-values[i], values[i]-loB); */
    if(error != 0)
      violation[i] = sortorder*error;
    basisvector[i] = i;
  }

  /* Sort decending , meaning that variables with the largest
     "violations" will be designated basic. Effectively, we are performing a
     greedy type algorithm, but start at the "least interesting" end. */
  sortByREAL(basisvector, violation, nsum, 1, FALSE);
  error = violation[1]; /* Used for setting the return value */

  /* Let us check for obvious row singularities and try to fix these.
     Note that we reuse the memory allocated to the violation array.
     First assemble necessary basis statistics... */
  slkpos = (int *) violation;
  n = nrows+1;
  MEMCLEAR(slkpos, n);
  isnz = (MYBOOL *) (slkpos+n+1);
  MEMCLEAR(isnz, n);
  for(i = 1; i <= nrows; i++) {
    j = abs(basisvector[i]);
    if(j <= nrows) {
      isnz[j] = TRUE;
      slkpos[j] = i;
    }
    else {
      j-= nrows;
      jj = mat->col_end[j-1];
      jj = COL_MAT_ROWNR(jj);
      isnz[jj] = TRUE;
    }
  }
  for(; i <= nsum; i++) {
    j = abs(basisvector[i]);
    if(j <= nrows)
      slkpos[j] = i;
  }

  /* ...then set the corresponding slacks basic for row rank deficient positions */
  for(j = 1; j <= nrows; j++) {
    if(slkpos[j] == 0)
      report(lp, SEVERE, "guess_basis: Internal error");
    if(!isnz[j]) {
      isnz[j] = TRUE;
      i = slkpos[j];
      swapINT(&basisvector[i], &basisvector[j]);
      basisvector[j] = abs(basisvector[j]);
    }
  }

  /* Adjust the non-basic indeces for the (proximal) bound state */
  for(i = nrows+1, basisnr = basisvector+i; i <= nsum; i++, basisnr++) {
    n = *basisnr;
    if(n <= nrows) {
      values[n] -= get_rh_lower(lp, n);
      if(values[n] <= eps)
        *basisnr = -(*basisnr);
    }
    else
      if(values[n]-eps <= get_lowbo(lp, n-nrows))
        *basisnr = -(*basisnr);
  }

/* Lastly normalize all basic variables to be coded as lower-bounded,
   or effectively zero-based in the case of free variables. */
  for(i = 1; i <= nrows; i++)
    basisvector[i] = -abs(basisvector[i]);

  /* Clean up and return status */
  status = (MYBOOL) (error <= eps);
Finish:
  FREE(values);
  FREE(violation);

  return( status );
}
Exemplo n.º 8
0
MYBOOL __WINAPI guess_basis(lprec *lp, REAL *guessvector, int *basisvector)
{
  MYBOOL *isnz, status = FALSE;
  REAL   *values = NULL, *violation = NULL,
         eps = lp->epsprimal,
         *value, error, upB, loB, sortorder = 1.0;
  int    i, j, jj, n, *rownr, *colnr, *slkpos,
         nrows = lp->rows, ncols = lp->columns;
  MATrec *mat = lp->matA;

  if(!mat_validate(mat))
    return( status );

  /* Create helper arrays */
  if(!allocREAL(lp, &values, lp->sum+1, TRUE) ||
     !allocREAL(lp, &violation, lp->sum+1, TRUE))
    goto Finish;

  /* Compute values of slack variables for given guess vector */
  i = 0;
  n = get_nonzeros(lp);
  rownr = &COL_MAT_ROWNR(i);
  colnr = &COL_MAT_COLNR(i);
  value = &COL_MAT_VALUE(i);
  for(; i < n; i++, rownr += matRowColStep, colnr += matRowColStep, value += matValueStep)
    values[*rownr] += unscaled_mat(lp, my_chsign(is_chsign(lp, *rownr), *value), *rownr, *colnr) *
                      guessvector[*colnr];
  MEMMOVE(values+nrows+1, guessvector+1, ncols);

  /* Initialize constraint bound violation measures (expressed as positive values) */
  for(i = 1; i <= nrows; i++) {
    upB = get_rh_upper(lp, i);
    loB = get_rh_lower(lp, i);
    error = values[i] - upB;
    if(error > -eps)
      violation[i] = sortorder*MAX(0,error);
    else {
      error = loB - values[i];
      if(error > -eps)
        violation[i] = sortorder*MAX(0,error);
      else if(my_infinite(lp, loB) && my_infinite(lp, upB))
        ;
      else if(my_infinite(lp, upB))
        violation[i] = sortorder*(loB - values[i]);
      else if(my_infinite(lp, loB))
        violation[i] = sortorder*(values[i] - upB);
      else
        violation[i] = -sortorder*MAX(upB - values[i], values[i] - loB);
    }
    basisvector[i] = i;
  }

  /* Initialize user variable bound violation measures (expressed as positive values) */
  for(i = 1; i <= ncols; i++) {
    n = nrows+i;
    upB = get_upbo(lp, i);
    loB = get_lowbo(lp, i);
    error = guessvector[i] - upB;
    if(error > -eps)
      violation[n] = sortorder*MAX(0,error);
    else {
      error = loB - values[n];
      if(error > -eps)
        violation[n] = sortorder*MAX(0,error);
      else if(my_infinite(lp, loB) && my_infinite(lp, upB))
        ;
      else if(my_infinite(lp, upB))
        violation[n] = sortorder*(loB - values[n]);
      else if(my_infinite(lp, loB))
        violation[n] = sortorder*(values[n] - upB);
      else
        violation[n] = -sortorder*MAX(upB - values[n], values[n] - loB);
    }
    basisvector[n] = n;
  }

  /* Sort decending by violation; this means that variables with
     the largest violations will be designated as basic */
  sortByREAL(basisvector, violation, lp->sum, 1, FALSE);
  error = violation[1];

  /* Adjust the non-basic indeces for the (proximal) bound state */
  for(i = nrows+1, rownr = basisvector+i; i <= lp->sum; i++, rownr++) {
    if(*rownr <= nrows) {
      values[*rownr] -= lp->orig_rhs[*rownr];
      if(values[*rownr] <= eps)
        *rownr = -(*rownr);
    }
    else
      if(values[i] <= get_lowbo(lp, (*rownr)-nrows)+eps)
        *rownr = -(*rownr);
  }

  /* Let us check for obvious row singularities and try to fix these;
     First assemble necessary basis statistics... */
  isnz = (MYBOOL *) values;
  MEMCLEAR(isnz, nrows+1);
  slkpos = (int *) violation;
  MEMCLEAR(slkpos, nrows+1);
  for(i = 1; i <= nrows; i++) {
    j = abs(basisvector[i]);
    if(j <= nrows) {
      isnz[j] = TRUE;
      slkpos[j] = i;
    }
    else {
      j-= nrows;
      jj = mat->col_end[j-1];
      isnz[COL_MAT_ROWNR(jj)] = TRUE;
/*      if(++jj < mat->col_end[j])
        isnz[COL_MAT_ROWNR(jj)] = TRUE; */
    }
  }
  for(; i <= lp->sum; i++) {
    j = abs(basisvector[i]);
    if(j <= nrows)
      slkpos[j] = i;
  }

  /* ...then set the corresponding slacks basic for row rank deficient positions */
  for(j = 1; j <= nrows; j++) {
#ifdef Paranoia
    if(slkpos[j] == 0)
      report(lp, SEVERE, "guess_basis: Internal error");
#endif
    if(!isnz[j]) {
      isnz[j] = TRUE;
      i = slkpos[j];
      swapINT(&basisvector[i], &basisvector[j]);
      basisvector[j] = abs(basisvector[j]);
    }
  }

  /* Lastly normalize all basic variables to be coded as lower-bounded */
  for(i = 1; i <= nrows; i++)
    basisvector[i] = -abs(basisvector[i]);

  /* Clean up and return status */
  status = (MYBOOL) (error <= eps);
Finish:
  FREE(values);
  FREE(violation);

  return( status );
}
Exemplo n.º 9
0
MYBOOL __WINAPI guess_basis(lprec *lp, REAL *guessvector, int *basisvector)
{
  MYBOOL status = FALSE;
  REAL   *values = NULL, *violation = NULL,
         *value, error, upB, loB, sortorder = 1.0;
  int    i, n, *rownr, *colnr;
  MATrec *mat = lp->matA;

  if(!mat_validate(lp->matA))
    return( status );

  /* Create helper arrays */
  if(!allocREAL(lp, &values, lp->sum+1, TRUE) ||
     !allocREAL(lp, &violation, lp->sum+1, TRUE))
    goto Finish;

  /* Compute values of slack variables for given guess vector */
  i = 0;
  n = get_nonzeros(lp);
  rownr = &COL_MAT_ROWNR(i);
  colnr = &COL_MAT_COLNR(i);
  value = &COL_MAT_VALUE(i);
  for(; i < n; i++, rownr += matRowColStep, colnr += matRowColStep, value += matValueStep)
    values[*rownr] += unscaled_mat(lp, my_chsign(is_chsign(lp, *rownr), *value), *rownr, *colnr) *
                      guessvector[*colnr];
  MEMMOVE(values+lp->rows+1, guessvector+1, lp->columns);

  /* Initialize constraint bound violation measures */
  for(i = 1; i <= lp->rows; i++) {
    upB = get_rh_upper(lp, i);
    loB = get_rh_lower(lp, i);
    error = values[i] - upB;
    if(error > lp->epsprimal)
      violation[i] = sortorder*error;
    else {
      error = loB - values[i];
      if(error > lp->epsprimal)
        violation[i] = sortorder*error;
      else if(is_infinite(lp, loB) && is_infinite(lp, upB))
        ;
      else if(is_infinite(lp, upB))
        violation[i] = sortorder*(loB - values[i]);
      else if(is_infinite(lp, loB))
        violation[i] = sortorder*(values[i] - upB);
      else
        violation[i] = - sortorder*MAX(upB - values[i], values[i] - loB);
    }
    basisvector[i] = i;
  }

  /* Initialize user variable bound violation measures */
  for(i = 1; i <= lp->columns; i++) {
    n = lp->rows+i;
    upB = get_upbo(lp, i);
    loB = get_lowbo(lp, i);
    error = guessvector[i] - upB;
    if(error > lp->epsprimal)
      violation[n] = sortorder*error;
    else {
      error = loB - values[n];
      if(error > lp->epsprimal)
        violation[n] = sortorder*error;
      else if(is_infinite(lp, loB) && is_infinite(lp, upB))
        ;
      else if(is_infinite(lp, upB))
        violation[n] = sortorder*(loB - values[n]);
      else if(is_infinite(lp, loB))
        violation[n] = sortorder*(values[n] - upB);
      else
        violation[n] = - sortorder*MAX(upB - values[n], values[n] - loB);
    }
    basisvector[n] = n;
  }

  /* Sort decending by violation; this means that variables with
     the largest violations will be designated as basic */
  sortByREAL(basisvector, violation, lp->sum, 1, FALSE);

  /* Adjust the non-basic indeces for the (proximal) bound state */
  error = lp->epsprimal;
  for(i = lp->rows+1, rownr = basisvector+i; i <= lp->sum; i++, rownr++) {
    if(*rownr <= lp->rows) {
      if(values[*rownr] <= get_rh_lower(lp, *rownr)+error)
        *rownr = -(*rownr);
    }
    else
      if(values[i] <= get_lowbo(lp, (*rownr)-lp->rows)+error)
        *rownr = -(*rownr);
  }

  /* Clean up and return status */
  status = (MYBOOL) (violation[1] == 0);
Finish:
  FREE(values);
  FREE(violation);


  return( status );
}
Exemplo n.º 10
0
MYBOOL crash_basis(lprec *lp)
{
  int     i;
  MATrec  *mat = lp->matA;
  MYBOOL  ok = TRUE;

  /* Initialize basis indicators */
  if(lp->basis_valid)
    lp->var_basic[0] = FALSE;
  else
    default_basis(lp);

  /* Set initial partial pricing blocks */
  if(lp->rowblocks != NULL)
    lp->rowblocks->blocknow = 1;
  if(lp->colblocks != NULL)
    lp->colblocks->blocknow = ((lp->crashmode == CRASH_NONE) || (lp->colblocks->blockcount == 1) ? 1 : 2);

  /* Construct a basis that is in some measure the "most feasible" */
  if((lp->crashmode == CRASH_MOSTFEASIBLE) && mat_validate(mat)) {
    /* The logic here follows Maros */
    LLrec   *rowLL = NULL, *colLL = NULL;
    int     ii, rx, cx, ix, nz;
    REAL    wx, tx, *rowMAX = NULL, *colMAX = NULL;
    int     *rowNZ = NULL, *colNZ = NULL, *rowWT = NULL, *colWT = NULL;
    REAL    *value;
    int     *rownr, *colnr;

    report(lp, NORMAL, "crash_basis: 'Most feasible' basis crashing selected\n");

    /* Tally row and column non-zero counts */
    ok = allocINT(lp,  &rowNZ, lp->rows+1,     TRUE) &&
         allocINT(lp,  &colNZ, lp->columns+1,  TRUE) &&
         allocREAL(lp, &rowMAX, lp->rows+1,    FALSE) &&
         allocREAL(lp, &colMAX, lp->columns+1, FALSE);
    if(!ok)
      goto Finish;

    nz = mat_nonzeros(mat);
    rownr = &COL_MAT_ROWNR(0);
    colnr = &COL_MAT_COLNR(0);
    value = &COL_MAT_VALUE(0);
    for(i = 0; i < nz;
        i++, rownr += matRowColStep, colnr += matRowColStep, value += matValueStep) {
      rx = *rownr;
      cx = *colnr;
      wx = fabs(*value);
      rowNZ[rx]++;
      colNZ[cx]++;
      if(i == 0) {
        rowMAX[rx] = wx;
        colMAX[cx] = wx;
        colMAX[0]  = wx;
      }
      else {
        SETMAX(rowMAX[rx], wx);
        SETMAX(colMAX[cx], wx);
        SETMAX(colMAX[0],  wx);
      }
    }
    /* Reduce counts for small magnitude to preserve stability */
    rownr = &COL_MAT_ROWNR(0);
    colnr = &COL_MAT_COLNR(0);
    value = &COL_MAT_VALUE(0);
    for(i = 0; i < nz;
        i++, rownr += matRowColStep, colnr += matRowColStep, value += matValueStep) {
      rx = *rownr;
      cx = *colnr;
      wx = fabs(*value);
#ifdef CRASH_SIMPLESCALE
      if(wx < CRASH_THRESHOLD * colMAX[0]) {
        rowNZ[rx]--;
        colNZ[cx]--;
      }
#else
      if(wx < CRASH_THRESHOLD * rowMAX[rx])
        rowNZ[rx]--;
      if(wx < CRASH_THRESHOLD * colMAX[cx])
        colNZ[cx]--;
#endif
    }

    /* Set up priority tables */
    ok = allocINT(lp, &rowWT, lp->rows+1, TRUE);
    createLink(lp->rows,    &rowLL, NULL);
    ok &= (rowLL != NULL);
    if(!ok)
      goto Finish;
    for(i = 1; i <= lp->rows; i++) {
      if(get_constr_type(lp, i)==EQ)
        ii = 3;
      else if(lp->upbo[i] < lp->infinite)
        ii = 2;
      else if(fabs(lp->rhs[i]) < lp->infinite)
        ii = 1;
      else
        ii = 0;
      rowWT[i] = ii;
      if(ii > 0)
        appendLink(rowLL, i);
    }
    ok = allocINT(lp, &colWT, lp->columns+1, TRUE);
    createLink(lp->columns, &colLL, NULL);
    ok &= (colLL != NULL);
    if(!ok)
      goto Finish;
    for(i = 1; i <= lp->columns; i++) {
      ix = lp->rows+i;
      if(is_unbounded(lp, i))
        ii = 3;
      else if(lp->upbo[ix] >= lp->infinite)
        ii = 2;
      else if(fabs(lp->upbo[ix]-lp->lowbo[ix]) > lp->epsmachine)
        ii = 1;
      else
        ii = 0;
      colWT[i] = ii;
      if(ii > 0)
        appendLink(colLL, i);
    }

    /* Loop over all basis variables */
    for(i = 1; i <= lp->rows; i++) {

      /* Select row */
      rx = 0;
      wx = -lp->infinite;
      for(ii = firstActiveLink(rowLL); ii > 0; ii = nextActiveLink(rowLL, ii)) {
        tx = rowWT[ii] - CRASH_SPACER*rowNZ[ii];
        if(tx > wx) {
          rx = ii;
          wx = tx;
        }
      }
      if(rx == 0)
        break;
      removeLink(rowLL, rx);

      /* Select column */
      cx = 0;
      wx = -lp->infinite;
      for(ii = mat->row_end[rx-1]; ii < mat->row_end[rx]; ii++) {

        /* Update NZ column counts for row selected above */
        tx = fabs(ROW_MAT_VALUE(ii));
        ix = ROW_MAT_COLNR(ii);
#ifdef CRASH_SIMPLESCALE
        if(tx >= CRASH_THRESHOLD * colMAX[0])
#else
        if(tx >= CRASH_THRESHOLD * colMAX[ix])
#endif
          colNZ[ix]--;
        if(!isActiveLink(colLL, ix) || (tx < CRASH_THRESHOLD * rowMAX[rx]))
          continue;

        /* Now do the test for best pivot */
        tx = my_sign(lp->orig_obj[ix]) - my_sign(ROW_MAT_VALUE(ii));
        tx = colWT[ix] + CRASH_WEIGHT*tx - CRASH_SPACER*colNZ[ix];
        if(tx > wx) {
          cx = ix;
          wx = tx;
        }
      }
      if(cx == 0)
        break;
      removeLink(colLL, cx);

      /* Update row NZ counts */
      ii = mat->col_end[cx-1];
      rownr = &COL_MAT_ROWNR(ii);
      value = &COL_MAT_VALUE(ii);
      for(; ii < mat->col_end[cx];
          ii++, rownr += matRowColStep, value += matValueStep) {
        wx = fabs(*value);
        ix = *rownr;
#ifdef CRASH_SIMPLESCALE
        if(wx >= CRASH_THRESHOLD * colMAX[0])
#else
        if(wx >= CRASH_THRESHOLD * rowMAX[ix])
#endif
          rowNZ[ix]--;
      }

      /* Set new basis variable */
      set_basisvar(lp, rx, lp->rows+cx);
    }

    /* Clean up */
Finish:
    FREE(rowNZ);
    FREE(colNZ);
    FREE(rowMAX);
    FREE(colMAX);
    FREE(rowWT);
    FREE(colWT);
    freeLink(&rowLL);
    freeLink(&colLL);
  }

  /* Construct a basis that is in some measure the "least degenerate" */
  else if((lp->crashmode == CRASH_LEASTDEGENERATE) && mat_validate(mat)) {
    /* The logic here follows Maros */
    LLrec   *rowLL = NULL, *colLL = NULL;
    int     ii, rx, cx, ix, nz, *merit = NULL;
    REAL    *value, wx, hold, *rhs = NULL, *eta = NULL;
    int     *rownr, *colnr;

    report(lp, NORMAL, "crash_basis: 'Least degenerate' basis crashing selected\n");

    /* Create temporary arrays */
    ok = allocINT(lp,  &merit, lp->columns + 1, FALSE) &&
         allocREAL(lp, &eta, lp->rows + 1, FALSE) &&
         allocREAL(lp, &rhs, lp->rows + 1, FALSE);
    createLink(lp->columns, &colLL, NULL);
    createLink(lp->rows, &rowLL, NULL);
    ok &= (colLL != NULL) && (rowLL != NULL);
    if(!ok)
      goto FinishLD;
    MEMCOPY(rhs, lp->orig_rhs, lp->rows + 1);
    for(i = 1; i <= lp->columns; i++)
      appendLink(colLL, i);
    for(i = 1; i <= lp->rows; i++)
      appendLink(rowLL, i);

    /* Loop until we have found enough new bases */
    while(colLL->count > 0) {

      /* Tally non-zeros matching in RHS and each active column */
      nz = mat_nonzeros(mat);
      rownr = &COL_MAT_ROWNR(0);
      colnr = &COL_MAT_COLNR(0);
      ii = 0;
      MEMCLEAR(merit, lp->columns + 1);
      for(i = 0; i < nz;
          i++, rownr += matRowColStep, colnr += matRowColStep) {
        rx = *rownr;
        cx = *colnr;
        if(isActiveLink(colLL, cx) && (rhs[rx] != 0)) {
          merit[cx]++;
          ii++;
        }
      }
      if(ii == 0)
        break;

      /* Find maximal match; break ties with column length */
      i = firstActiveLink(colLL);
      cx = i;
      for(i = nextActiveLink(colLL, i); i != 0; i = nextActiveLink(colLL, i)) {
        if(merit[i] >= merit[cx]) {
          if((merit[i] > merit[cx]) || (mat_collength(mat, i) > mat_collength(mat, cx)))
            cx = i;
        }
      }

      /* Determine the best pivot row */
      i = mat->col_end[cx-1];
      nz = mat->col_end[cx];
      rownr = &COL_MAT_ROWNR(i);
      value = &COL_MAT_VALUE(i);
      rx = 0;
      wx = 0;
      MEMCLEAR(eta, lp->rows + 1);
      for(; i < nz;
          i++, rownr += matRowColStep, value += matValueStep) {
        ix = *rownr;
        hold = *value;
        eta[ix] = rhs[ix] / hold;
        hold = fabs(hold);
        if(isActiveLink(rowLL, ix) && (hold > wx)) {
          wx = hold;
          rx = ix;
        }
      }

      /* Set new basis variable */
      if(rx > 0) {

        /* We have to update the rhs vector for the implied transformation
          in order to be able to find the new RHS non-zero pattern */
        for(i = 1; i <= lp->rows; i++)
           rhs[i] -= wx * eta[i];
        rhs[rx] = wx;

        /* Do the exchange */
        set_basisvar(lp, rx, lp->rows+cx);
        removeLink(rowLL, rx);
      }
      removeLink(colLL, cx);

    }

    /* Clean up */
FinishLD:
    FREE(merit);
    FREE(rhs);
    freeLink(&rowLL);
    freeLink(&colLL);

  }
  return( ok );
}
Exemplo n.º 11
0
int CurtisReidScales(lprec *lp, MYBOOL _Advanced, REAL *FRowScale, REAL *FColScale)
{
  int    i, row, col, ent, nz;
  REAL   *RowScalem2, *ColScalem2,
         *RowSum, *ColSum,
         *residual_even, *residual_odd;
  REAL   sk,   qk,     ek,
         skm1, qkm1,   ekm1,
         qkm2, qkqkm1, ekm2, ekekm1,
         absvalue, logvalue,
         StopTolerance;
  int    *RowCount, *ColCount, colMax;
  int    Result;
  MATrec *mat = lp->matA;
  REAL   *value;
  int    *rownr, *colnr;

  if(CurtisReidMeasure(lp, _Advanced, FRowScale, FColScale)<0.1*get_nonzeros(lp))
  return(0);

  /* Allocate temporary memory and find RowSum and ColSum measures */
  nz = get_nonzeros(lp);
  colMax = lp->columns;

  allocREAL(lp, &RowSum, lp->rows+1, TRUE);
  allocINT(lp,  &RowCount, lp->rows+1, TRUE);
  allocREAL(lp, &residual_odd, lp->rows+1, TRUE);

  allocREAL(lp, &ColSum, colMax+1, TRUE);
  allocINT(lp,  &ColCount, colMax+1, TRUE);
  allocREAL(lp, &residual_even, colMax+1, TRUE);

  allocREAL(lp, &RowScalem2, lp->rows+1, FALSE);
  allocREAL(lp, &ColScalem2, colMax+1, FALSE);

  /* Set origin for row scaling */
  for(i = 1; i <= colMax; i++) {
    absvalue=fabs(lp->orig_obj[i]);
    if(absvalue>0) {
      logvalue = log(absvalue);
      ColSum[i] += logvalue;
      RowSum[0] += logvalue;
      ColCount[i]++;
      RowCount[0]++;
    }
  }

  value = &(COL_MAT_VALUE(0));
  rownr = &(COL_MAT_ROWNR(0));
  colnr = &(COL_MAT_COLNR(0));
  for(i = 0; i < nz;
      i++, value += matValueStep, rownr += matRowColStep, colnr += matRowColStep) {
    absvalue=fabs(*value);
    if(absvalue>0) {
      logvalue = log(absvalue);
      ColSum[*colnr] += logvalue;
      RowSum[*rownr] += logvalue;
      ColCount[*colnr]++;
      RowCount[*rownr]++;
    }
  }

  /* Make sure we dont't have division by zero errors */
  for(row = 0; row <= lp->rows; row++)
    if(RowCount[row] == 0)
      RowCount[row] = 1;
  for(col = 1; col <= colMax; col++)
    if(ColCount[col] == 0)
      ColCount[col] = 1;

  /* Initialize to RowScale = RowCount-1 RowSum
                   ColScale = 0.0
                   residual = ColSum - ET RowCount-1 RowSum */

  StopTolerance= MAX(lp->scalelimit-floor(lp->scalelimit), DEF_SCALINGEPS);
  StopTolerance *= (REAL) nz;
  for(row = 0; row <= lp->rows; row++) {
    FRowScale[row] = RowSum[row] / (REAL) RowCount[row];
    RowScalem2[row] = FRowScale[row];
  }

  /* Compute initial residual */
  for(col = 1; col <= colMax; col++) {
    FColScale[col] = 0;
    ColScalem2[col] = 0;
    residual_even[col] = ColSum[col];

    if(lp->orig_obj[col] != 0)
      residual_even[col] -= RowSum[0] / (REAL) RowCount[0];

    i = mat->col_end[col-1];
    rownr = &(COL_MAT_ROWNR(i));
    ent = mat->col_end[col];
    for(; i < ent;
        i++, rownr += matRowColStep) {
      residual_even[col] -= RowSum[*rownr] / (REAL) RowCount[*rownr];
    }
  }

  /* Compute sk */
  sk = 0;
  skm1 = 0;
  for(col = 1; col <= colMax; col++)
    sk += (residual_even[col]*residual_even[col]) / (REAL) ColCount[col];

  Result = 0;
  qk=1; qkm1=0; qkm2=0;
  ek=0; ekm1=0; ekm2=0;

  while(sk>StopTolerance) {
  /* Given the values of residual and sk, construct
     ColScale (when pass is even)
     RowScale (when pass is odd)  */

    qkqkm1 = qk * qkm1;
    ekekm1 = ek * ekm1;
    if((Result % 2) == 0) { /* pass is even; construct RowScale[pass+1] */
      if(Result != 0) {
        for(row = 0; row <= lp->rows; row++)
          RowScalem2[row] = FRowScale[row];
        if(qkqkm1 != 0) {
          for(row = 0; row <= lp->rows; row++)
            FRowScale[row]*=(1 + ekekm1 / qkqkm1);
          for(row = 0; row<=lp->rows; row++)
            FRowScale[row]+=(residual_odd[row] / (qkqkm1 * (REAL) RowCount[row]) -
                             RowScalem2[row] * ekekm1 / qkqkm1);
        }
      }
    }
    else { /* pass is odd; construct ColScale[pass+1] */
      for(col = 1; col <= colMax; col++)
        ColScalem2[col] = FColScale[col];
      if(qkqkm1 != 0) {
        for(col = 1; col <= colMax; col++)
          FColScale[col] *= (1 + ekekm1 / qkqkm1);
        for(col = 1; col <= colMax; col++)
          FColScale[col] += (residual_even[col] / ((REAL) ColCount[col] * qkqkm1) -
                             ColScalem2[col] * ekekm1 / qkqkm1);
      }
    }

    /* update residual and sk (pass + 1) */
    if((Result % 2) == 0) { /* even */
       /* residual */
      for(row = 0; row <= lp->rows; row++)
        residual_odd[row] *= ek;

      for(i = 1; i <= colMax; i++)
        if(lp->orig_obj[i] != 0)
          residual_odd[0] += (residual_even[i] / (REAL) ColCount[i]);

      rownr = &(COL_MAT_ROWNR(0));
      colnr = &(COL_MAT_COLNR(0));
      for(i = 0; i < nz;
          i++, rownr += matRowColStep, colnr += matRowColStep) {
        residual_odd[*rownr] += (residual_even[*colnr] / (REAL) ColCount[*colnr]);
      }
      for(row = 0; row <= lp->rows; row++)
        residual_odd[row] *= (-1 / qk);

      /* sk */
      skm1 = sk;
      sk = 0;
      for(row = 0; row <= lp->rows; row++)
        sk += (residual_odd[row]*residual_odd[row]) / (REAL) RowCount[row];
    }
    else { /* odd */
      /* residual */
      for(col = 1; col <= colMax; col++)
        residual_even[col] *= ek;

      for(i = 1; i <= colMax; i++)
        if(lp->orig_obj[i] != 0)
          residual_even[i] += (residual_odd[0] / (REAL) RowCount[0]);

      rownr = &(COL_MAT_ROWNR(0));
      colnr = &(COL_MAT_COLNR(0));
      for(i = 0; i < nz;
          i++, rownr += matRowColStep, colnr += matRowColStep) {
        residual_even[*colnr] += (residual_odd[*rownr] / (REAL) RowCount[*rownr]);
      }
      for(col = 1; col <= colMax; col++)
        residual_even[col] *= (-1 / qk);

      /* sk */
      skm1 = sk;
      sk = 0;
      for(col = 1; col <= colMax; col++)
        sk += (residual_even[col]*residual_even[col]) / (REAL) ColCount[col];
    }

    /* Compute ek and qk */
    ekm2=ekm1;
    ekm1=ek;
    ek=qk * sk / skm1;

    qkm2=qkm1;
    qkm1=qk;
    qk=1-ek;

    Result++;
  }

  /* Synchronize the RowScale and ColScale vectors */
  ekekm1 = ek * ekm1;
  if(qkm1 != 0) {
  if((Result % 2) == 0) { /* pass is even, compute RowScale */
    for(row = 0; row<=lp->rows; row++)
      FRowScale[row]*=(1.0 + ekekm1 / qkm1);
    for(row = 0; row<=lp->rows; row++)
      FRowScale[row]+=(residual_odd[row] / (qkm1 * (REAL) RowCount[row]) -
                      RowScalem2[row] * ekekm1 / qkm1);
  }
  else { /* pass is odd, compute ColScale */
    for(col=1; col<=colMax; col++)
      FColScale[col]*=(1 + ekekm1 / qkm1);
    for(col=1; col<=colMax; col++)
      FColScale[col]+=(residual_even[col] / ((REAL) ColCount[col] * qkm1) -
                       ColScalem2[col] * ekekm1 / qkm1);
  }
  }

  /* Do validation, if indicated */
  if(FALSE && mat_validate(mat)){
    double check, error;

    /* CHECK: M RowScale + E ColScale = RowSum */
    error = 0;
    for(row = 0; row <= lp->rows; row++) {
      check = (REAL) RowCount[row] * FRowScale[row];
      if(row == 0) {
        for(i = 1; i <= colMax; i++) {
          if(lp->orig_obj[i] != 0)
            check += FColScale[i];
        }
      }
      else {
        i = mat->row_end[row-1];
        ent = mat->row_end[row];
        for(; i < ent; i++) {
          col = ROW_MAT_COLNR(i);
          check += FColScale[col];
        }
      }
      check -= RowSum[row];
      error += check*check;
    }

    /* CHECK: E^T RowScale + N ColScale = ColSum */
    error = 0;
    for(col = 1; col <= colMax; col++) {
      check = (REAL) ColCount[col] * FColScale[col];

      if(lp->orig_obj[col] != 0)
        check += FRowScale[0];

      i = mat->col_end[col-1];
      ent = mat->col_end[col];
      rownr = &(COL_MAT_ROWNR(i));
      for(; i < ent;
          i++, rownr += matRowColStep) {
        check += FRowScale[*rownr];
      }
      check -= ColSum[col];
      error += check*check;
    }
  }

  /* Convert to scaling factors (rounding to nearest power
     of 2 can optionally be done as a separate step later) */
  for(col = 1; col <= colMax; col++) {
    absvalue = exp(-FColScale[col]);
    if(absvalue < MIN_SCALAR) absvalue = MIN_SCALAR;
    if(absvalue > MAX_SCALAR) absvalue = MAX_SCALAR;
    if(!is_int(lp,col) || is_integerscaling(lp))
        FColScale[col] = absvalue;
    else
        FColScale[col] = 1;
  }
  for(row = 0; row <= lp->rows; row++) {
    absvalue = exp(-FRowScale[row]);
    if(absvalue < MIN_SCALAR) absvalue = MIN_SCALAR;
    if(absvalue > MAX_SCALAR) absvalue = MAX_SCALAR;
    FRowScale[row] = absvalue;
  }

 /* free temporary memory */
  FREE(RowSum);
  FREE(ColSum);
  FREE(RowCount);
  FREE(ColCount);
  FREE(residual_even);
  FREE(residual_odd);
  FREE(RowScalem2);
  FREE(ColScalem2);

  return(Result);

}