vtk-m2/vtkm/worklet/AverageByKey.h
2015-06-24 14:55:22 -04:00

114 lines
4.6 KiB
C++

//============================================================================
// Copyright (c) Kitware, Inc.
// All rights reserved.
// See LICENSE.txt for details.
// This software is distributed WITHOUT ANY WARRANTY; without even
// the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
// PURPOSE. See the above copyright notice for more information.
//
// Copyright 2014 Sandia Corporation.
// Copyright 2014 UT-Battelle, LLC.
// Copyright 2014 Los Alamos National Security.
//
// Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
// the U.S. Government retains certain rights in this software.
//
// Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
// Laboratory (LANL), the U.S. Government retains certain rights in
// this software.
//============================================================================
#ifndef vtk_m_worklet_AverageByKey_h
#define vtk_m_worklet_AverageByKey_h
#include <vtkm/cont/DeviceAdapter.h>
#include <vtkm/cont/ArrayHandle.h>
#include <vtkm/cont/ArrayHandleCounting.h>
#include <vtkm/cont/ArrayHandlePermutation.h>
#include <vtkm/cont/DynamicArrayHandle.h>
#include <vtkm/cont/Timer.h>
#include <vtkm/Pair.h>
#include <vtkm/Types.h>
#include <vtkm/worklet/DispatcherMapField.h>
#include <vtkm/worklet/WorkletMapField.h>
#include <vtkm/cont/DeviceAdapterAlgorithm.h>
#include <vtkm/cont/ArrayHandleConstant.h>
#include <vtkm/cont/ArrayHandleCompositeVector.h>
namespace vtkm {
namespace worklet {
template <class ValueType>
struct DivideWorklet: public vtkm::worklet::WorkletMapField{
typedef void ControlSignature(FieldIn<>, FieldIn<>, FieldOut<>);
typedef void ExecutionSignature(_1, _2, _3);
VTKM_EXEC_EXPORT void operator()(
const ValueType &v, vtkm::Id &count, ValueType &vout) const
{ vout = v * (1./count); }
};
template <class KeyType, class ValueType, class DeviceAdapter>
void AverageByKey( const vtkm::cont::ArrayHandle<KeyType> &keyArray,
const vtkm::cont::ArrayHandle<ValueType> &valueArray,
vtkm::cont::ArrayHandle<KeyType> &outputKeyArray,
vtkm::cont::ArrayHandle<ValueType> &outputValueArray)
{
vtkm::cont::ArrayHandle<ValueType> sumArray;
// sort the indexed array
vtkm::cont::ArrayHandle<KeyType> keyArraySorted;
vtkm::cont::ArrayHandlePermutation<vtkm::cont::ArrayHandle<vtkm::Id>, vtkm::cont::ArrayHandle<ValueType> >
valueArraySorted ;
{
vtkm::cont::ArrayHandleCounting<vtkm::Id> indexArray(0, keyArray.GetNumberOfValues());
vtkm::cont::ArrayHandle<vtkm::Id> indexArraySorted;
vtkm::cont::DeviceAdapterAlgorithm<DeviceAdapter>::Copy( keyArray, keyArraySorted );
vtkm::cont::DeviceAdapterAlgorithm<DeviceAdapter>::Copy( indexArray, indexArraySorted );
vtkm::cont::DeviceAdapterAlgorithm<DeviceAdapter>::SortByKey( keyArraySorted, indexArraySorted, std::less<KeyType>() ) ;
valueArraySorted = vtkm::cont::make_ArrayHandlePermutation( indexArraySorted, valueArray );
}
vtkm::cont::ArrayHandleConstant<vtkm::Id> constOneArray(1, valueArray.GetNumberOfValues());
vtkm::cont::ArrayHandle<vtkm::Id> countArray;
#if 1 // reduce twice : fastest
vtkm::cont::DeviceAdapterAlgorithm<DeviceAdapter>::ReduceByKey(
keyArraySorted, valueArraySorted,
outputKeyArray, sumArray,
vtkm::internal::Add() );
vtkm::cont::DeviceAdapterAlgorithm<DeviceAdapter>::ReduceByKey(
keyArraySorted, constOneArray,
outputKeyArray, countArray,
vtkm::internal::Add() );
#else // use zip (a little slower)
auto inputZipHandle = vtkm::cont::make_ArrayHandleZip(valueArraySorted, constOneArray);
auto outputZipHandle = vtkm::cont::make_ArrayHandleZip(sumArray, countArray);
vtkm::cont::DeviceAdapterAlgorithm<DeviceAdapter>::ReduceByKey( keyArraySorted, inputZipHandle,
outputKeyArray, outputZipHandle,
ZipAdd() );
#endif
// get average
DispatcherMapField<DivideWorklet<ValueType> >().Invoke(
sumArray, countArray, outputValueArray);
}
template <class KeyType, class ValueType>
void AverageByKey( const vtkm::cont::ArrayHandle<KeyType> &keyArray,
const vtkm::cont::ArrayHandle<ValueType> &valueArray,
vtkm::cont::ArrayHandle<KeyType> &outputKeyArray,
vtkm::cont::ArrayHandle<ValueType> &outputValueArray)
{
AverageByKey<KeyType, ValueType, VTKM_DEFAULT_DEVICE_ADAPTER_TAG> (keyArray, valueArray, outputKeyArray, outputValueArray);
}
}} // vtkm::worklet
#endif //vtk_m_worklet_AverageByKey_h