rpg/scft/iterator/AmIteratorGrid.tpp

#ifndef RPG_AM_ITERATOR_GRID_TPP
#define RPG_AM_ITERATOR_GRID_TPP
 
/*
* PSCF - Polymer Self-Consistent Field
*
* Copyright 2015 - 2025, The Regents of the University of Minnesota
* Distributed under the terms of the GNU General Public License.
*/
 
#include "AmIteratorGrid.h"
#include <rpg/system/System.h>
#include <rpg/solvers/Mixture.h>
#include <rpg/field/Domain.h>
#include <prdc/crystal/UnitCell.h>
#include <prdc/cuda/resources.h>
#include <pscf/inter/Interaction.h>
#include <pscf/iterator/NanException.h>
#include <util/global.h>
#include <cmath>
 
namespace Pscf {
namespace Rpg {
 
   using namespace Util;
   using namespace Prdc;
   using namespace Prdc::Cuda;
 
   /*
   * Constructor.
   */
   template <int D>
   AmIteratorGrid<D>::AmIteratorGrid(System<D>& system)
    : Iterator<D>(system)
   {
      setClassName("AmIteratorGrid");
      isSymmetric_ = false;
   }
 
   /*
   * Destructor.
   */
   template <int D>
   AmIteratorGrid<D>::~AmIteratorGrid()
   {}
 
   /*
   * Read parameter file block.
   */
   template <int D>
   void AmIteratorGrid<D>::readParameters(std::istream& in)
   {
      // Read param file format for base class
      Base::readParameters(in);
      Base::readErrorType(in);
 
      // Default parameter values
      isFlexible_ = 1;
      scaleStress_ = 10.0;
 
      int np = system().domain().unitCell().nParameter();
      UTIL_CHECK(np > 0);
      UTIL_CHECK(np <= 6);
      UTIL_CHECK(system().domain().unitCell().lattice() 
                  != UnitCell<D>::Null);
 
      // Read in optional isFlexible value
      readOptional(in, "isFlexible", isFlexible_);
 
      // Populate flexibleParams_ based on isFlexible_ (all 0s or all 1s),
      // then optionally overwrite with user input from param file
      if (isFlexible_) {
         flexibleParams_.clear();
         for (int i = 0; i < np; i++) {
            flexibleParams_.append(true); // Set all values to true
         }
         // Read optional flexibleParams_ array to overwrite current array
         readOptionalFSArray(in, "flexibleParams", flexibleParams_, np);
         if (nFlexibleParams() == 0) isFlexible_ = false;
      } else { // isFlexible_ = false
         flexibleParams_.clear();
         for (int i = 0; i < np; i++) {
            flexibleParams_.append(false); // Set all values to false
         }
      }
 
      // Read optional scaleStress value
      readOptional(in, "scaleStress", scaleStress_);
 
      // Read optional mixing parameters (lambda, useLambdaRamp, r)
      Base::readMixingParameters(in);
 
      // Allocate local modified copy of Interaction class
      interaction_.setNMonomer(system().mixture().nMonomer());
 
   }
 
   /*
   * Output timing results to log file.
   */
   template<int D>
   void AmIteratorGrid<D>::outputTimers(std::ostream& out) const
   {
      // Output timing results, if requested.
      out << "\n";
      out << "Iterator times contributions:\n";
      Base::outputTimers(out);
   }
 
   // Protected virtual function
 
   /*
   * Setup before entering iteration loop.
   */
   template <int D>
   void AmIteratorGrid<D>::setup(bool isContinuation)
   {
      AmIteratorTmpl<Iterator<D>, VectorT>::setup(isContinuation);
      interaction_.update(system().interaction());
   }
 
   /*
   * Checks if the system has an initial guess.
   */
   template <int D>
   bool AmIteratorGrid<D>::hasInitialGuess()
   { return system().w().hasData(); }
 
   // Compute the number of elements in the residual vector.
   template <int D>
   int AmIteratorGrid<D>::nElements()
   {
      const int nMonomer = system().mixture().nMonomer();
      const int nMesh = system().domain().mesh().size();
 
      int nEle = nMonomer*nMesh;
 
      if (isFlexible_) {
         nEle += nFlexibleParams();
      }
 
      return nEle;
   }
 
   /*
   * Get the current w fields and lattice parameters.
   */
   template <int D>
   void AmIteratorGrid<D>::getCurrent(VectorT& curr)
   {
      const int nMonomer = system().mixture().nMonomer();
      const int nMesh = system().domain().mesh().size();
      const int n = nElements();
      UTIL_CHECK(curr.capacity() == n);
 
      // Loop to unfold the system fields and store them in one long array
      for (int i = 0; i < nMonomer; i++) {
         VecOp::eqV(curr, system().w().rgrid(i), i*nMesh, 0, nMesh);
      }
 
      // If flexible unit cell, also store unit cell parameters
      if (isFlexible_) {
         const int nParam = system().domain().unitCell().nParameter();
         FSArray<double,6> const & parameters
                              = system().domain().unitCell().parameters();
 
         // convert into a cudaReal array
         HostDArray<cudaReal> tempH(nFlexibleParams());
         int counter = 0;
         for (int i = 0; i < nParam; i++) {
            if (flexibleParams_[i]) {
               tempH[counter] = scaleStress_ * parameters[i];
               counter++;
            }
         }
         UTIL_CHECK(counter == tempH.capacity());
 
         // Copy parameters to the end of the curr array
         VectorT tempD;
         tempD.associate(curr, nMonomer*nMesh, tempH.capacity());
         tempD = tempH; // copy from host to device
      }
   }
 
   /*
   * Solve MDE for current state of system.
   */
   template <int D>
   void AmIteratorGrid<D>::evaluate()
   {
      // Solve MDEs for current omega field
      system().compute(isFlexible_);
   }
 
   /*
   * Gets the residual vector from system.
   */
   template <int D>
   void AmIteratorGrid<D>::getResidual(VectorT& resid)
   {
      const int n = nElements();
      const int nMonomer = system().mixture().nMonomer();
      const int nMesh = system().domain().mesh().size();
 
      // Initialize residuals to zero. Kernel will take care of potential
      // additional elements (n vs nMesh).
      VecOp::eqS(resid, 0.0);
 
      // Array of VectorT arrays associated with slices of resid.
      // one VectorT array per monomer species, each of size nMesh.
      DArray<VectorT> residSlices;
      residSlices.allocate(nMonomer);
      for (int i = 0; i < nMonomer; i++) {
         residSlices[i].associate(resid, i*nMesh, nMesh);
      }
 
      // Compute SCF residuals
      for (int i = 0; i < nMonomer; i++) {
         for (int j = 0; j < nMonomer; j++) {
            VecOp::addVcVcVc(residSlices[i], residSlices[i], 1.0,
                             system().c().rgrid(j), interaction_.chi(i, j),
                             system().w().rgrid(j), -interaction_.p(i, j));
         }
      }
 
      // If iterator has mask, account for it in residual values
      if (system().mask().hasData()) {
         double coeff = -1.0 / interaction_.sumChiInverse();
         for (int i = 0; i < nMonomer; ++i) {
            VecOp::addEqVc(residSlices[i], system().mask().rgrid(), coeff);
         }
      }
 
      // If iterator has external fields, account for them in the values
      // of the residuals
      if (system().h().hasData()) {
         for (int i = 0; i < nMonomer; ++i) {
            for (int j = 0; j < nMonomer; ++j) {
               double p = interaction_.p(i,j);
               VecOp::addEqVc(residSlices[i], system().h().rgrid(j), p);
            }
         }
      }
 
      // If ensemble is not canonical, account for incompressibility.
      if (!system().mixture().isCanonical()) {
         cudaReal factor = 1.0 / interaction_.sumChiInverse();
         VecOp::subEqS(resid, factor, 0, nMonomer*nMesh);
      } else {
         for (int i = 0; i < nMonomer; i++) {
            // Find current average
            cudaReal average = findAverage(residSlices[i]);
            // subtract out average to set residual average to zero
            VecOp::subEqS(residSlices[i], average);
         }
      }
 
      // If variable unit cell, compute stress residuals
      if (isFlexible_) {
         const int nParam = system().domain().unitCell().nParameter();
         HostDArray<cudaReal> stressH(nFlexibleParams());
 
         int counter = 0;
         for (int i = 0; i < nParam; i++) {
            if (flexibleParams_[i]) {
               double str = stress(i);
               stressH[counter] = -1 * scaleStress_ * str;
               counter++;
            }
         }
         UTIL_CHECK(counter == stressH.capacity());
 
         VectorT stressD;
         stressD.associate(resid, nMonomer*nMesh, stressH.capacity());
         stressD = stressH; // copy from host to device
      }
   }
 
   /*
   * Update the system with a new trial field vector.
   */
   template <int D>
   void AmIteratorGrid<D>::update(VectorT& newGuess)
   {
      const int nMonomer = system().mixture().nMonomer();
      const int nMesh = system().domain().mesh().size();
 
      // If canonical, explicitly set homogeneous field components
      if (system().mixture().isCanonical()) {
         cudaReal average, wAverage, cAverage;
         for (int i = 0; i < nMonomer; i++) {
 
            // Define array associated with a slice of newGuess
            VectorT ngSlice;
            ngSlice.associate(newGuess, i*nMesh, nMesh);
 
            // Find current spatial average
            average = findAverage(ngSlice);
 
            // Subtract average from field, setting average to zero
            VecOp::subEqS(ngSlice, average);
 
            // Compute the average omega(i) due to interactions
            wAverage = 0.0;
            for (int j = 0; j < nMonomer; j++) {
               cAverage = findAverage(system().c().rgrid(j));
               wAverage += interaction_.chi(i,j) * cAverage;
            }
 
            // If external fields exist, add them to wAverage
            if (system().h().hasData()) {
               wAverage += findAverage(system().h().rgrid(i));
            }
 
            // Add new average omega value to the field
            VecOp::addEqS(ngSlice, wAverage);
         }
      }
 
      // Set w fields in system w container
      system().w().setRGrid(newGuess);
 
      // If flexible unit cell, update cell parameters
      if (isFlexible_) {
         FSArray<double,6> parameters;
         parameters = system().domain().unitCell().parameters();
         const int nParam = system().domain().unitCell().nParameter();
 
         // transfer from device to host
         HostDArray<cudaReal> tempH(nFlexibleParams());
         tempH.copySlice(newGuess, nMonomer*nMesh);
 
         const double coeff = 1.0 / scaleStress_;
         int counter = 0;
         for (int i = 0; i < nParam; i++) {
            if (flexibleParams_[i]) {
               parameters[i] = coeff * tempH[i];
               counter++;
            }
         }
         UTIL_CHECK(counter == tempH.capacity());
 
         system().setUnitCell(parameters);
      }
   }
 
   /*
   * Output relevant system details to the iteration log file.
   */
   template<int D>
   void AmIteratorGrid<D>::outputToLog()
   {
      if (isFlexible_ && verbose() > 1) {
         UnitCell<D> const & unitCell = system().domain().unitCell();
         const int nParam = unitCell.nParameter();
         const int nMonomer = system().mixture().nMonomer();
         const int nMesh = system().domain().mesh().size();
 
         // Transfer stress residuals from device to host
         HostDArray<cudaReal> tempH(nFlexibleParams());
         tempH.copySlice(residual(), nMonomer*nMesh);
 
         int counter = 0;
         for (int i = 0; i < nParam; i++) {
            if (flexibleParams_[i]) {
               double str = tempH[counter] / (-1.0 * scaleStress_);
               Log::file()
                   << " Cell Param  " << i << " = "
                   << Dbl(unitCell.parameters()[i], 15)
                   << " , stress = "
                   << Dbl(str, 15)
                   << "\n";
               counter++;
            }
         }
      }
   }
 
   // Private virtual functions for vector math
 
   /*
   * Set vector a equal to vector b (a = b).
   */
   template <int D>
   void AmIteratorGrid<D>::setEqual(VectorT& a,
                                    VectorT const & b)
   {
      UTIL_CHECK(b.capacity() == a.capacity());
      VecOp::eqV(a, b);
   }
 
   /*
   * Compute and return inner product of two real fields.
   */
   template <int D>
   double AmIteratorGrid<D>::dotProduct(VectorT const & a,
                                        VectorT const & b)
   {
      UTIL_CHECK(a.capacity() == b.capacity());
      double val = Reduce::innerProduct(a, b);
      if (std::isnan(val)) { // if value is NaN, throw NanException
         throw NanException("AmIteratorGrid::dotProduct",
                            __FILE__, __LINE__, 0);
      }
      return val;
   }
 
   /*
   * Find the maximum magnitude element of a residual vector.
   */
   template <int D>
   double AmIteratorGrid<D>::maxAbs(VectorT const & a)
   {
      double val = Reduce::maxAbs(a);
      if (std::isnan(val)) { // if value is NaN, throw NanException
         throw NanException("AmIteratorGrid::maxAbs",
                             __FILE__, __LINE__, 0);
      }
      return val;
   }
 
   /*
   * Compute the vector difference a = b - c
   */
   template <int D>
   void AmIteratorGrid<D>::subVV(VectorT& a,
                                 VectorT const & b,
                                 VectorT const & c)
   {  VecOp::subVV(a, b, c); }
 
   /*
   * Composite a += b*c for vectors a and b, scalar c
   */
   template <int D>
   void AmIteratorGrid<D>::addEqVc(VectorT& a,
                                   VectorT const & b,
                                   double c)
   {  VecOp::addEqVc(a, b, c); }
 
 
   // Private member functions specific to this implementation
 
   // Calculate the average value of an array.
   template<int D>
   cudaReal AmIteratorGrid<D>::findAverage(VectorT const & field)
   {  return Reduce::sum(field) / (double) field.capacity(); }
 
}
}
#endif