src/gmxlib/gmx_lapack/dlaebz.c

   1 /*
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   4  * Copyright (c) 2012, by the GROMACS development team, led by
   5  * David van der Spoel, Berk Hess, Erik Lindahl, and including many
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  11  * as published by the Free Software Foundation; either version 2.1
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  35 #include <math.h>
  36 #include "gmx_lapack.h"
  37
  38 void
  39 F77_FUNC(dlaebz,DLAEBZ)(int *ijob,
  40         int *nitmax,
  41         int *n,
  42         int *mmax,
  43         int *minp,
  44         int *nbmin,
  45         double *abstol,
  46         double *reltol,
  47         double *pivmin,
  48         double *d__,
  49         double *e,
  50         double *e2,
  51         int *nval,
  52         double *ab,
  53         double *c__,
  54         int *mout,
  55         int *nab,
  56         double *work,
  57         int *iwork,
  58         int *info)
  59 {
  60     int nab_dim1, nab_offset, ab_dim1, ab_offset, i__1, i__2, i__3, i__4,
  61             i__5, i__6;
  62     double d__1, d__2, d__3, d__4;
  63
  64     int j, kf, ji, kl, jp, jit;
  65     double tmp1, tmp2;
  66     int itmp1, itmp2, kfnew, klnew;
  67
  68     nab_dim1 = *mmax;
  69     nab_offset = 1 + nab_dim1;
  70     nab -= nab_offset;
  71     ab_dim1 = *mmax;
  72     ab_offset = 1 + ab_dim1;
  73     ab -= ab_offset;
  74     --d__;
  75     --e;
  76     --e2;
  77     --nval;
  78     --c__;
  79     --work;
  80     --iwork;
  81
  82     *info = 0;
  83     if (*ijob < 1 || *ijob > 3) {
  84         *info = -1;
  85         return;
  86     }
  87
  88     if (*ijob == 1) {
  89
  90         *mout = 0;
  91
  92         i__1 = *minp;
  93         for (ji = 1; ji <= i__1; ++ji) {
  94             for (jp = 1; jp <= 2; ++jp) {
  95                 tmp1 = d__[1] - ab[ji + jp * ab_dim1];
  96                 if (fabs(tmp1) < *pivmin) {
  97                     tmp1 = -(*pivmin);
  98                 }
  99                 nab[ji + jp * nab_dim1] = 0;
 100                 if (tmp1 <= 0.) {
 101                     nab[ji + jp * nab_dim1] = 1;
 102                 }
 103
 104                 i__2 = *n;
 105                 for (j = 2; j <= i__2; ++j) {
 106                     tmp1 = d__[j] - e2[j - 1] / tmp1 - ab[ji + jp * ab_dim1];
 107                     if (fabs(tmp1) < *pivmin) {
 108                         tmp1 = -(*pivmin);
 109                     }
 110                     if (tmp1 <= 0.) {
 111                         ++nab[ji + jp * nab_dim1];
 112                     }
 113                 }
 114             }
 115             *mout = *mout + nab[ji + (nab_dim1 << 1)] - nab[ji + nab_dim1];
 116         }
 117         return;
 118     }
 119
 120     kf = 1;
 121     kl = *minp;
 122
 123     if (*ijob == 2) {
 124         i__1 = *minp;
 125         for (ji = 1; ji <= i__1; ++ji) {
 126             c__[ji] = (ab[ji + ab_dim1] + ab[ji + (ab_dim1 << 1)]) * .5;
 127         }
 128     }
 129
 130     i__1 = *nitmax;
 131     for (jit = 1; jit <= i__1; ++jit) {
 132
 133         if (kl - kf + 1 >= *nbmin && *nbmin > 0) {
 134
 135             i__2 = kl;
 136             for (ji = kf; ji <= i__2; ++ji) {
 137
 138                 work[ji] = d__[1] - c__[ji];
 139                 iwork[ji] = 0;
 140                 if (work[ji] <= *pivmin) {
 141                     iwork[ji] = 1;
 142                     d__1 = work[ji], d__2 = -(*pivmin);
 143                     work[ji] = (d__1<d__2) ? d__1 : d__2;
 144                 }
 145
 146                 i__3 = *n;
 147                 for (j = 2; j <= i__3; ++j) {
 148                     work[ji] = d__[j] - e2[j - 1] / work[ji] - c__[ji];
 149                     if (work[ji] <= *pivmin) {
 150                         ++iwork[ji];
 151                         d__1 = work[ji], d__2 = -(*pivmin);
 152                         work[ji] = (d__1<d__2) ? d__1 : d__2;
 153                     }
 154                 }
 155             }
 156
 157             if (*ijob <= 2) {
 158
 159                 klnew = kl;
 160                 i__2 = kl;
 161                 for (ji = kf; ji <= i__2; ++ji) {
 162
 163                   i__5 = nab[ji + nab_dim1];
 164                   i__6 = iwork[ji];
 165                   i__3 = nab[ji + (nab_dim1 << 1)];
 166                   i__4 = (i__5>i__6) ? i__5 : i__6;
 167                     iwork[ji] = (i__3<i__4) ? i__3 : i__4;
 168
 169                     if (iwork[ji] == nab[ji + (nab_dim1 << 1)]) {
 170
 171                         ab[ji + (ab_dim1 << 1)] = c__[ji];
 172
 173                     } else if (iwork[ji] == nab[ji + nab_dim1]) {
 174
 175                         ab[ji + ab_dim1] = c__[ji];
 176                     } else {
 177                         ++klnew;
 178                         if (klnew <= *mmax) {
 179
 180                             ab[klnew + (ab_dim1 << 1)] = ab[ji + (ab_dim1 <<
 181                                     1)];
 182                             nab[klnew + (nab_dim1 << 1)] = nab[ji + (nab_dim1
 183                                     << 1)];
 184                             ab[klnew + ab_dim1] = c__[ji];
 185                             nab[klnew + nab_dim1] = iwork[ji];
 186                             ab[ji + (ab_dim1 << 1)] = c__[ji];
 187                             nab[ji + (nab_dim1 << 1)] = iwork[ji];
 188                         } else {
 189                             *info = *mmax + 1;
 190                         }
 191                     }
 192                 }
 193                 if (*info != 0) {
 194                     return;
 195                 }
 196                 kl = klnew;
 197             } else {
 198
 199                 i__2 = kl;
 200                 for (ji = kf; ji <= i__2; ++ji) {
 201                     if (iwork[ji] <= nval[ji]) {
 202                         ab[ji + ab_dim1] = c__[ji];
 203                         nab[ji + nab_dim1] = iwork[ji];
 204                     }
 205                     if (iwork[ji] >= nval[ji]) {
 206                         ab[ji + (ab_dim1 << 1)] = c__[ji];
 207                         nab[ji + (nab_dim1 << 1)] = iwork[ji];
 208                     }
 209                 }
 210             }
 211
 212         } else {
 213
 214             klnew = kl;
 215             i__2 = kl;
 216             for (ji = kf; ji <= i__2; ++ji) {
 217
 218                 tmp1 = c__[ji];
 219                 tmp2 = d__[1] - tmp1;
 220                 itmp1 = 0;
 221                 if (tmp2 <= *pivmin) {
 222                     itmp1 = 1;
 223                     d__1 = tmp2, d__2 = -(*pivmin);
 224                     tmp2 = (d__1<d__2) ? d__1 : d__2;
 225                 }
 226
 227                 i__3 = *n;
 228                 for (j = 2; j <= i__3; ++j) {
 229                     tmp2 = d__[j] - e2[j - 1] / tmp2 - tmp1;
 230                     if (tmp2 <= *pivmin) {
 231                         ++itmp1;
 232                         d__1 = tmp2, d__2 = -(*pivmin);
 233                         tmp2 = (d__1<d__2) ? d__1 : d__2;
 234                     }
 235                 }
 236
 237                 if (*ijob <= 2) {
 238
 239                     i__5 = nab[ji + nab_dim1];
 240                     i__3 = nab[ji + (nab_dim1 << 1)];
 241                     i__4 = (i__5>itmp1) ? i__5 : itmp1;
 242                     itmp1 = (i__3<i__4) ? i__3 : i__4;
 243
 244                     if (itmp1 == nab[ji + (nab_dim1 << 1)]) {
 245
 246                         ab[ji + (ab_dim1 << 1)] = tmp1;
 247
 248                     } else if (itmp1 == nab[ji + nab_dim1]) {
 249
 250                         ab[ji + ab_dim1] = tmp1;
 251                     } else if (klnew < *mmax) {
 252
 253                         ++klnew;
 254                         ab[klnew + (ab_dim1 << 1)] = ab[ji + (ab_dim1 << 1)];
 255                         nab[klnew + (nab_dim1 << 1)] = nab[ji + (nab_dim1 <<
 256                                 1)];
 257                         ab[klnew + ab_dim1] = tmp1;
 258                         nab[klnew + nab_dim1] = itmp1;
 259                         ab[ji + (ab_dim1 << 1)] = tmp1;
 260                         nab[ji + (nab_dim1 << 1)] = itmp1;
 261                     } else {
 262                         *info = *mmax + 1;
 263                         return;
 264                     }
 265                 } else {
 266
 267                     if (itmp1 <= nval[ji]) {
 268                         ab[ji + ab_dim1] = tmp1;
 269                         nab[ji + nab_dim1] = itmp1;
 270                     }
 271                     if (itmp1 >= nval[ji]) {
 272                         ab[ji + (ab_dim1 << 1)] = tmp1;
 273                         nab[ji + (nab_dim1 << 1)] = itmp1;
 274                     }
 275                 }
 276             }
 277             kl = klnew;
 278
 279         }
 280
 281         kfnew = kf;
 282         i__2 = kl;
 283         for (ji = kf; ji <= i__2; ++ji) {
 284             tmp1 = fabs(ab[ji + (ab_dim1 << 1)] - ab[ji + ab_dim1]);
 285             d__3 = fabs(ab[ji + (ab_dim1 << 1)]);
 286             d__4 = fabs(ab[ji + ab_dim1]);
 287             tmp2 = (d__3>d__4) ? d__3 : d__4;
 288             d__1 = (*abstol>*pivmin) ? *abstol : *pivmin;
 289             d__2 = *reltol * tmp2;
 290             if (tmp1 < ((d__1>d__2) ? d__1 : d__2) || nab[ji + nab_dim1] >= nab[ji + (
 291                     nab_dim1 << 1)]) {
 292
 293                 if (ji > kfnew) {
 294                     tmp1 = ab[ji + ab_dim1];
 295                     tmp2 = ab[ji + (ab_dim1 << 1)];
 296                     itmp1 = nab[ji + nab_dim1];
 297                     itmp2 = nab[ji + (nab_dim1 << 1)];
 298                     ab[ji + ab_dim1] = ab[kfnew + ab_dim1];
 299                     ab[ji + (ab_dim1 << 1)] = ab[kfnew + (ab_dim1 << 1)];
 300                     nab[ji + nab_dim1] = nab[kfnew + nab_dim1];
 301                     nab[ji + (nab_dim1 << 1)] = nab[kfnew + (nab_dim1 << 1)];
 302                     ab[kfnew + ab_dim1] = tmp1;
 303                     ab[kfnew + (ab_dim1 << 1)] = tmp2;
 304                     nab[kfnew + nab_dim1] = itmp1;
 305                     nab[kfnew + (nab_dim1 << 1)] = itmp2;
 306                     if (*ijob == 3) {
 307                         itmp1 = nval[ji];
 308                         nval[ji] = nval[kfnew];
 309                         nval[kfnew] = itmp1;
 310                     }
 311                 }
 312                 ++kfnew;
 313             }
 314         }
 315         kf = kfnew;
 316
 317         i__2 = kl;
 318         for (ji = kf; ji <= i__2; ++ji) {
 319             c__[ji] = (ab[ji + ab_dim1] + ab[ji + (ab_dim1 << 1)]) * .5;
 320         }
 321
 322         if (kf > kl) {
 323             break;
 324         }
 325     }
 326
 327     i__1 = kl + 1 - kf;
 328     if(i__1>0)
 329       *info = i__1;
 330
 331     *mout = kl;
 332
 333     return;
 334
 335 }
 336
 337