Commit 01edfed8 authored by Nguyen, Thien Minh's avatar Nguyen, Thien Minh
Browse files

Code clean up 



- Removed an unused class declaration.

- Added helper to pick observable evaluator in the workflow execute.

Signed-off-by: default avatarThien Nguyen <nguyentm@ornl.gov>
parent 52d9fbfa

lib/qsim/impls/qsim_impl.cpp

+23 −7
Original line number Diff line number Diff line
@@ -2,6 +2,26 @@ 
#include "xacc.hpp"

#include "xacc_service.hpp"



namespace {

using namespace qcor;

std::shared_ptr<qsim::CostFunctionEvaluator>

getEvaluator(Observable *observable, const HeterogeneousMap &params) {

  // If an evaluator was provided explicitly:

  if (params.pointerLikeExists<qsim::CostFunctionEvaluator>("evaluator")) {

    return xacc::as_shared_ptr(

        params.getPointerLike<qsim::CostFunctionEvaluator>("evaluator"));

  }



  // Cost Evaluator was provided by name:

  if (params.stringExists("evaluator")) {

    return qsim::getObjEvaluator(observable, params.getString("evaluator"));

  }



  // No specific evaluator/evaluation method was requested,

  // use the default one (partial tomography based).

  return qsim::getObjEvaluator(observable);

}

} // namespace

namespace qcor {

namespace qsim {

Ansatz TrotterEvolution::create_ansatz(Observable *obs,
@@ -37,13 +57,14 @@ bool TimeDependentWorkflow::initialize(const HeterogeneousMap &params) { 
  }



  t_final = nbSteps * dt;

  config_params = params;

  return true;

}



QuantumSimulationResult

TimeDependentWorkflow::execute(const QuantumSimulationModel &model) {

  QuantumSimulationResult result;

  evaluator = getObjEvaluator(model.observable);

  evaluator = getEvaluator(model.observable, config_params);

  auto ham_func = model.hamiltonian;

  // A TD workflow: stepping through Trotter steps,

  // compute expectations at each step.
@@ -100,12 +121,7 @@ VqeWorkflow::execute(const QuantumSimulationModel &model) { 
  // If the model includes a concrete variational ansatz:

  if (model.user_defined_ansatz) {

    auto nParams = model.user_defined_ansatz->nParams();

    if (config_params.pointerLikeExists<CostFunctionEvaluator>("evaluator")) {

      evaluator = xacc::as_shared_ptr(

          config_params.getPointerLike<CostFunctionEvaluator>("evaluator"));

    } else {

      evaluator = getObjEvaluator(model.observable);

    }

    evaluator = getEvaluator(model.observable, config_params);



    OptFunction f(

        [&](const std::vector<double> &x, std::vector<double> &dx) {

lib/qsim/impls/qsim_impl.hpp

+1 −16
Original line number Diff line number Diff line
@@ -25,22 +25,6 @@ public: 
  virtual const std::string description() const override { return ""; }

};



// other methods.



// Estimate the cost function based on bitstring distribution,

// e.g. actual quantum hardware.

// Note: we can sub-class CostFunctionEvaluator to add post-processing or

// analysis of the result.

class BitCountExpectationEstimator : public CostFunctionEvaluator {

public:

  // Evaluate the cost

  virtual double

  evaluate(std::shared_ptr<CompositeInstruction> state_prep) override;



private:

  size_t nb_samples;

};



// VQE-type workflow which involves an optimization loop, i.e. an Optimizer.

class VqeWorkflow : public QuantumSimulationWorkflow {

public:
@@ -67,6 +51,7 @@ public: 
  virtual const std::string description() const override { return ""; }



private:

  HeterogeneousMap config_params;

  double t_0;

  double t_final;

  double dt;