include/gmx_arpack.h

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
   3  *
   4  * This file is part of Gromacs        Copyright (c) 1991-2004
   5  * David van der Spoel, Erik Lindahl, University of Groningen.
   6  * Copyright (c) 2012, by the GROMACS development team, led by
   7  * David van der Spoel, Berk Hess, Erik Lindahl, and including many
   8  * others, as listed in the AUTHORS file in the top-level source
   9  * directory and at http://www.gromacs.org.
  10  *
  11  * GROMACS is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public License
  13  * as published by the Free Software Foundation; either version 2.1
  14  * of the License, or (at your option) any later version.
  15  *
  16  * GROMACS is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19  * Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public
  22  * License along with GROMACS; if not, see
  23  * http://www.gnu.org/licenses, or write to the Free Software Foundation,
  24  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
  25  *
  26  * If you want to redistribute modifications to GROMACS, please
  27  * consider that scientific software is very special. Version
  28  * control is crucial - bugs must be traceable. We will be happy to
  29  * consider code for inclusion in the official distribution, but
  30  * derived work must not be called official GROMACS. Details are found
  31  * in the README & COPYING files - if they are missing, get the
  32  * official version at http://www.gromacs.org.
  33  *
  34  * To help us fund GROMACS development, we humbly ask that you cite
  35  * the research papers on the package. Check out http://www.gromacs.org.
  36  */
  37
  38 #ifndef _GMX_ARPACK_H
  39 #define _GMX_ARPACK_H
  40
  41 #include "visibility.h"
  42 #ifdef __cplusplus
  43 extern "C" {
  44 #endif
  45
  46 /*! \file
  47  * \brief Selected routines from ARPACK
  48  *
  49  * This file contains a subset of ARPACK functions to perform
  50  * diagonalization and SVD for sparse matrices in Gromacs.
  51  *
  52  * Consult the main ARPACK site for detailed documentation:
  53  * http://www.caam.rice.edu/software/ARPACK/
  54  *
  55  * Below, we just list the options and any specific differences
  56  * from ARPACK. The code is essentially the same, but the routines
  57  * have been made thread-safe by using extra workspace arrays.
  58  */
  59
  60
  61 /*! \brief Implicitly Restarted Arnoldi Iteration, double precision.
  62  *
  63  *  Reverse communication interface for the Implicitly Restarted Arnoldi
  64  *  Iteration.  For symmetric problems this reduces to a variant of the
  65  *  Lanczos method. See the ARPACK site for details.
  66  *
  67  *  \param ido     Reverse communication flag. Set to 0 first time.
  68  *                 Upon return with ido=-1 or ido=1 you should calculate
  69  *                 Y=A*X and recall the routine. Return with ido=2 means
  70  *                 Y=B*X should be calculated. ipntr[0] is the pointer in
  71  *                 workd for X, ipntr[1] is the index for Y.
  72  *                 Return with ido=99 means it finished.
  73  *  \param bmat    'I' for standard eigenproblem, 'G' for generalized.
  74  *  \param n       Order of eigenproblem.
  75  *  \param which   Which eigenvalues to calculate. 'LA' for largest
  76  *                 algebraic, 'SA' for smallest algebraic, 'LM' for largest
  77  *                 magnitude, 'SM' for smallest magnitude, and finally
  78  *                 'BE' (both ends) to calculate half from each end of
  79  *                 the spectrum.
  80  *  \param nev     Number of eigenvalues to calculate. 0<nev<n.
  81  *  \param tol     Tolerance. Machine precision of it is 0.
  82  *  \param resid   Optional starting residual vector at input if info=1,
  83  *                 otherwise a random one is used. Final residual vector on
  84  *                 return.
  85  *  \param ncv     Number of columns in matrix v.
  86  *  \param v       N*NCV matrix. V contain the Lanczos basis vectors.
  87  *  \param ldv     Leading dimension of v.
  88  *  \param iparam  Integer array, size 11. Same contents as arpack.
  89  *  \param ipntr   Integer array, size 11. Points to starting locations
  90  *                 in the workd/workl arrays. Same contents as arpack.
  91  *  \param workd   Double precision work array, length 3*n+4.
  92  *                 Provide the same array for all calls, and don't touch it.
  93  *                 IMPORTANT: This is 4 units larger than standard ARPACK!
  94  *  \param iwork   Integer work array, size 80.
  95  *                 Provide the same array for all calls, and don't touch it.
  96  *                 IMPORTANT: New argument compared to standard ARPACK!
  97  *  \param workl   Double precision work array, length lwork.
  98  *  \param lworkl  Length of the work array workl. Must be at least ncv*(ncv+8)
  99  *  \param info    Set info to 0 to use random initial residual vector,
 100  *                 or to 1 if you provide a one. On output, info=0 means
 101  *                 normal exit, 1 that max number of iterations was reached,
 102  *                 and 3 that no shifts could be applied. Negative numbers
 103  *                 correspond to errors in the arguments provided.
 104  */
 105 GMX_LIBGMX_EXPORT
 106 void
 107 F77_FUNC(dsaupd,DSAUPD)(int *     ido,
 108                         const char *    bmat,
 109                         int *     n,
 110                         const char *      which,
 111                         int *     nev,
 112                         double *  tol,
 113                         double *  resid,
 114                         int *     ncv,
 115                         double *  v,
 116                         int *     ldv,
 117                         int *     iparam,
 118                         int *     ipntr,
 119                         double *  workd,
 120                         int *     iwork,
 121                         double *  workl,
 122                         int *     lworkl,
 123                         int *     info);
 124
 125
 126
 127 /*! \brief Get eigenvalues/vectors after Arnoldi iteration, double prec.
 128  *
 129  *  See the ARPACK site for details. You must have finished the interative
 130  *  part with dsaupd() before calling this function.
 131  *
 132  *  \param rvec    1 if you want eigenvectors, 0 if not.
 133  *  \param howmny  'A' if you want all nvec vectors, 'S' if you
 134  *                 provide a subset selection in select[].
 135  *  \param select  Integer array, dimension nev. Indices of the
 136  *                 eigenvectors to calculate. Fortran code means we
 137  *                 start counting on 1. This array must be given even in
 138  *                 howmny is 'A'. (Arpack documentation is wrong on this).
 139  *  \param d       Double precision array, length nev. Eigenvalues.
 140  *  \param z       Double precision array, n*nev. Eigenvectors.
 141  *  \param ldz     Leading dimension of z. Normally n.
 142  *  \param sigma   Shift if iparam[6] is 3,4, or 5. Ignored otherwise.
 143  *  \param bmat    Provide the same argument as you did to dsaupd()
 144  *  \param n       Provide the same argument as you did to dsaupd()
 145  *  \param which   Provide the same argument as you did to dsaupd()
 146  *  \param nev     Provide the same argument as you did to dsaupd()
 147  *  \param tol     Provide the same argument as you did to dsaupd()
 148  *  \param resid   Provide the same argument as you did to dsaupd()
 149  *                 The array must not be touched between the two function calls!
 150  *  \param ncv     Provide the same argument as you did to dsaupd()
 151  *  \param v       Provide the same argument as you did to dsaupd()
 152  *                 The array must not be touched between the two function calls!
 153  *  \param ldv     Provide the same argument as you did to dsaupd()
 154  *  \param iparam  Provide the same argument as you did to dsaupd()
 155  *                 The array must not be touched between the two function calls!
 156  *  \param ipntr   Provide the same argument as you did to dsaupd()
 157  *                 The array must not be touched between the two function calls!
 158  *  \param workd   Provide the same argument as you did to dsaupd()
 159  *                 The array must not be touched between the two function calls!
 160  *  \param workl   Double precision work array, length lwork.
 161  *                 The array must not be touched between the two function calls!
 162  *  \param lworkl  Provide the same argument as you did to dsaupd()
 163  *  \param info    Provide the same argument as you did to dsaupd()
 164  */
 165 GMX_LIBGMX_EXPORT
 166 void
 167 F77_FUNC(dseupd,DSEUPD)(int *     rvec,
 168                         const char *    howmny,
 169                         int *     select,
 170                         double *  d,
 171                         double *  z,
 172                         int *     ldz,
 173                         double *  sigma,
 174                         const char *    bmat,
 175                         int *     n,
 176                         const char *    which,
 177                         int *     nev,
 178                         double *  tol,
 179                         double *  resid,
 180                         int *     ncv,
 181                         double *  v,
 182                         int *     ldv,
 183                         int *     iparam,
 184                         int *     ipntr,
 185                         double *  workd,
 186                         double *  workl,
 187                         int *     lworkl,
 188                         int *     info);
 189
 190
 191
 192
 193
 194 /*! \brief Implicitly Restarted Arnoldi Iteration, single precision.
 195  *
 196  *  Reverse communication interface for the Implicitly Restarted Arnoldi
 197  *  Iteration.  For symmetric problems this reduces to a variant of the
 198  *  Lanczos method. See the ARPACK site for details.
 199  *
 200  *  \param ido     Reverse communication flag. Set to 0 first time.
 201  *                 Upon return with ido=-1 or ido=1 you should calculate
 202  *                 Y=A*X and recall the routine. Return with ido=2 means
 203  *                 Y=B*X should be calculated. ipntr[0] is the pointer in
 204  *                 workd for X, ipntr[1] is the index for Y.
 205  *                 Return with ido=99 means it finished.
 206  *  \param bmat    'I' for standard eigenproblem, 'G' for generalized.
 207  *  \param n       Order of eigenproblem.
 208  *  \param which   Which eigenvalues to calculate. 'LA' for largest
 209  *                 algebraic, 'SA' for smallest algebraic, 'LM' for largest
 210  *                 magnitude, 'SM' for smallest magnitude, and finally
 211  *                 'BE' (both ends) to calculate half from each end of
 212  *                 the spectrum.
 213  *  \param nev     Number of eigenvalues to calculate. 0<nev<n.
 214  *  \param tol     Tolerance. Machine precision of it is 0.
 215  *  \param resid   Optional starting residual vector at input if info=1,
 216  *                 otherwise a random one is used. Final residual vector on
 217  *                 return.
 218  *  \param ncv     Number of columns in matrix v.
 219  *  \param v       N*NCV matrix. V contain the Lanczos basis vectors.
 220  *  \param ldv     Leading dimension of v.
 221  *  \param iparam  Integer array, size 11. Same contents as arpack.
 222  *  \param ipntr   Integer array, size 11. Points to starting locations
 223  *                 in the workd/workl arrays. Same contents as arpack.
 224  *  \param workd   Single precision work array, length 3*n+4.
 225  *                 Provide the same array for all calls, and don't touch it.
 226  *                 IMPORTANT: This is 4 units larger than standard ARPACK!
 227  *  \param iwork   Integer work array, size 80.
 228  *                 Provide the same array for all calls, and don't touch it.
 229  *                 IMPORTANT: New argument compared to standard ARPACK!
 230  *  \param workl   Single precision work array, length lwork.
 231  *  \param lworkl  Length of the work array workl. Must be at least ncv*(ncv+8)
 232  *  \param info    Set info to 0 to use random initial residual vector,
 233  *                 or to 1 if you provide a one. On output, info=0 means
 234  *                 normal exit, 1 that max number of iterations was reached,
 235  *                 and 3 that no shifts could be applied. Negative numbers
 236  *                 correspond to errors in the arguments provided.
 237  */
 238 GMX_LIBGMX_EXPORT
 239 void
 240 F77_FUNC(ssaupd,SSAUPD)(int *     ido,
 241                         const char *    bmat,
 242                         int *     n,
 243                         const char *    which,
 244                         int *     nev,
 245                         float *   tol,
 246                         float *   resid,
 247                         int *     ncv,
 248                         float *   v,
 249                         int *     ldv,
 250                         int *     iparam,
 251                         int *     ipntr,
 252                         float *   workd,
 253                         int *     iwork,
 254                         float *   workl,
 255                         int *     lworkl,
 256                         int *     info);
 257
 258
 259
 260
 261
 262 /*! \brief Get eigenvalues/vectors after Arnoldi iteration, single prec.
 263  *
 264  *  See the ARPACK site for details. You must have finished the interative
 265  *  part with ssaupd() before calling this function.
 266  *
 267  *  \param rvec    1 if you want eigenvectors, 0 if not.
 268  *  \param howmny  'A' if you want all nvec vectors, 'S' if you
 269  *                 provide a subset selection in select[].
 270  *  \param select  Integer array, dimension nev. Indices of the
 271  *                 eigenvectors to calculate. Fortran code means we
 272  *                 start counting on 1. This array must be given even in
 273  *                 howmny is 'A'. (Arpack documentation is wrong on this).
 274  *  \param d       Single precision array, length nev. Eigenvalues.
 275  *  \param z       Single precision array, n*nev. Eigenvectors.
 276  *  \param ldz     Leading dimension of z. Normally n.
 277  *  \param sigma   Shift if iparam[6] is 3,4, or 5. Ignored otherwise.
 278  *  \param bmat    Provide the same argument as you did to ssaupd()
 279  *  \param n       Provide the same argument as you did to ssaupd()
 280  *  \param which   Provide the same argument as you did to ssaupd()
 281  *  \param nev     Provide the same argument as you did to ssaupd()
 282  *  \param tol     Provide the same argument as you did to ssaupd()
 283  *  \param resid   Provide the same argument as you did to ssaupd()
 284  *                 The array must not be touched between the two function calls!
 285  *  \param ncv     Provide the same argument as you did to ssaupd()
 286  *  \param v       Provide the same argument as you did to ssaupd()
 287  *                 The array must not be touched between the two function calls!
 288  *  \param ldv     Provide the same argument as you did to ssaupd()
 289  *  \param iparam  Provide the same argument as you did to ssaupd()
 290  *                 The array must not be touched between the two function calls!
 291  *  \param ipntr   Provide the same argument as you did to ssaupd()
 292  *                 The array must not be touched between the two function calls!
 293  *  \param workd   Provide the same argument as you did to ssaupd()
 294  *                 The array must not be touched between the two function calls!
 295  *  \param workl   Single precision work array, length lwork.
 296  *                 The array must not be touched between the two function calls!
 297  *  \param lworkl  Provide the same argument as you did to ssaupd()
 298  *  \param info    Provide the same argument as you did to ssaupd()
 299  */
 300 GMX_LIBGMX_EXPORT
 301 void
 302 F77_FUNC(sseupd,SSEUPD)(int *     rvec,
 303                         const char *    howmny,
 304                         int *     select,
 305                         float *   d,
 306                         float *   z,
 307                         int *     ldz,
 308                         float *   sigma,
 309                         const char *    bmat,
 310                         int *     n,
 311                         const char *    which,
 312                         int *     nev,
 313                         float *   tol,
 314                         float *   resid,
 315                         int *     ncv,
 316                         float *   v,
 317                         int *     ldv,
 318                         int *     iparam,
 319                         int *     ipntr,
 320                         float *   workd,
 321                         float *   workl,
 322                         int *     lworkl,
 323                         int *     info);
 324
 325 #ifdef __cplusplus
 326 }
 327 #endif
 328
 329 #endif
 330