src/gromacs/domdec/localatomsetdata.cpp

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  35 /*! \file
  36  * \internal \brief
  37  * Declares gmx::internal::LocalAtomSetDataData.
  38  *
  39  * \author Christian Blau <cblau@gwdg.de>
  40  * \ingroup module_domdec
  41  */
  42 #include "gmxpre.h"
  43
  44 #include "localatomsetdata.h"
  45
  46 #include <algorithm>
  47 #include <numeric>
  48
  49 #include "gromacs/domdec/ga2la.h"
  50
  51 namespace gmx
  52 {
  53
  54 namespace internal
  55 {
  56
  57 /********************************************************************
  58  * LocalAtomSetData
  59  */
  60
  61 LocalAtomSetData::LocalAtomSetData(ArrayRef<const int> globalIndex) :
  62     globalIndex_(globalIndex.begin(), globalIndex.end()), localIndex_(globalIndex.begin(), globalIndex.end())
  63 {
  64     collectiveIndex_.resize(localIndex_.size());
  65     std::iota(collectiveIndex_.begin(), collectiveIndex_.end(), 0);
  66 }
  67
  68 void
  69 LocalAtomSetData::setLocalAndCollectiveIndices(const gmx_ga2la_t &ga2la)
  70 {
  71     /* Loop over all the atom indices of the set to check which ones are local.
  72      * cf. dd_make_local_group_indices in groupcoord.cpp
  73      */
  74     int  numAtomsGlobal   = globalIndex_.size();
  75
  76     /* Clear vector without changing capacity,
  77      * because we expect the size of the vectors to vary little. */
  78     localIndex_.resize(0);
  79     collectiveIndex_.resize(0);
  80
  81     for (int iCollective = 0; iCollective < numAtomsGlobal; iCollective++)
  82     {
  83         if (const int *iLocal = ga2la.findHome(globalIndex_[iCollective]))
  84         {
  85             /* Save the atoms index in the local atom numbers array */
  86             /* The atom with this index is a home atom. */
  87             localIndex_.push_back(*iLocal);
  88
  89             /* Keep track of where this local atom belongs in the collective index array.
  90              * This is needed when reducing the local arrays to a collective/global array
  91              * in communicate_group_positions */
  92             collectiveIndex_.push_back(iCollective);
  93         }
  94     }
  95 }
  96
  97 } // namespace internal
  98
  99 } // namespace gmx