atlas::array::ArrayView< Value, Rank > Class Template Reference

Multi-dimensional access to a Array object or Field object. More...

#include <NativeArrayView.h>

Public Types
using	value_type = Value
using	non_const_value_type = typename std::remove_const< Value >::type
using	data_view_t = gridtools::data_view_tt< Value, Rank, gridtools::get_access_mode< Value >()>
using	value_type = Value
using	non_const_value_type = typename std::remove_const< Value >::type

Public Member Functions
ATLAS_HOST_DEVICE	ArrayView (const ArrayView &other)
	ArrayView (const Array &array, bool device_view)
	ArrayView (const ArrayView< value_type, Rank > &other)
	operator const ArrayView< value_type, Rank > & () const
value_type *	data ()
value_type const *	data () const
template<typename... Coords, typename = typename std::enable_if<( sizeof...( Coords ) == Rank ), int>::type>
ATLAS_HOST_DEVICE value_type &	operator() (Coords... c)
template<typename... Coords, typename = typename std::enable_if<( sizeof...( Coords ) == Rank ), int>::type>
ATLAS_HOST_DEVICE value_type const &	operator() (Coords... c) const
template<typename Int , bool EnableBool = true>
ATLAS_HOST_DEVICE std::enable_if<(Rank==1 &&EnableBool), const value_type & >::type	operator[] (Int idx) const
template<typename Int , bool EnableBool = true>
ATLAS_HOST_DEVICE std::enable_if<(Rank==1 &&EnableBool), value_type & >::type	operator[] (Int idx)
template<unsigned int Dim>
ATLAS_HOST_DEVICE idx_t	shape () const
ATLAS_HOST_DEVICE data_view_t &	data_view ()
ATLAS_HOST_DEVICE data_view_t const &	data_view () const
template<unsigned int Dim>
ATLAS_HOST_DEVICE idx_t	stride () const
size_t	size () const
bool	valid () const
bool	contiguous () const
void	dump (std::ostream &os) const
ENABLE_IF_NON_CONST void	assign (const value_type &value)
ENABLE_IF_NON_CONST void	assign (const std::initializer_list< value_type > &list)
const idx_t *	strides () const
const idx_t *	shape () const
template<typename Int >
idx_t	shape (Int idx) const
template<typename Int >
idx_t	stride (Int idx) const
template<typename... Args>
slice_t< Args... >::type	slice (Args... args)
template<typename... Args>
const_slice_t< Args... >::type	slice (Args... args) const
bool	isDeviceView () const
	ArrayView (const ArrayView &other)
	ArrayView (const ArrayView< value_type, Rank > &other)
	ArrayView (value_type *data, const ArrayShape &shape, const ArrayStrides &strides)
	operator const ArrayView< value_type, Rank > & () const
template<typename... Idx>
value_type &	operator() (Idx... idx)
	Multidimensional index operator: view(i,j,k,...)
template<typename... Ints>
const value_type &	operator() (Ints... idx) const
	Multidimensional index operator: view(i,j,k,...)
template<typename Int , bool EnableBool = true>
std::enable_if<(Rank==1 &&EnableBool), const value_type & >::type	operator[] (Int idx) const
	Access to data using square bracket [idx] operator {m-label m-warning} Rank==1. More...
template<typename Int , bool EnableBool = true>
std::enable_if<(Rank==1 &&EnableBool), value_type & >::type	operator[] (Int idx)
	Access to data using square bracket [idx] operator {m-label m-warning} Rank==1 More...
template<unsigned int Dim>
idx_t	shape () const
	Return number of values in dimension Dim (template argument) More...
template<unsigned int Dim>
idx_t	stride () const
	Return stride for values in dimension Dim (template argument)
size_t	size () const
	Return total number of values (accumulated over all dimensions)
const idx_t *	strides () const
const idx_t *	shape () const
template<typename Int >
idx_t	shape (Int idx) const
	Return number of values in dimension idx.
template<typename Int >
idx_t	stride (Int idx) const
	Return stride for values in dimension idx.
value_type const *	data () const
	Access to internal data. {m-label m-danger} dangerous
value_type *	data ()
	Access to internal data. {m-label m-danger} dangerous
bool	valid () const
bool	contiguous () const
	Return true when all values are contiguous in memory. More...
ENABLE_IF_NON_CONST void	assign (const value_type &value)
ENABLE_IF_NON_CONST void	assign (const std::initializer_list< value_type > &list)
void	dump (std::ostream &os) const
template<typename... Args>
slice_t< Args... >::type	slice (Args... args)
	Obtain a slice from this view: view.slice( Range, Range, ... More...
template<typename... Args>
const_slice_t< Args... >::type	slice (Args... args) const
	Obtain a slice from this view: view.slice( Range, Range, ... )

Static Public Member Functions
static constexpr idx_t	rank ()
static constexpr idx_t	rank ()
	Return the number of dimensions.

Static Public Attributes
static constexpr bool	is_const = std::is_const<Value>::value
static constexpr bool	is_non_const = !std::is_const<Value>::value
static constexpr int	RANK {Rank}

Friends
template<typename friendValue , int friendRank>
class	ArrayView

Detailed Description

template<typename Value, int Rank>
class atlas::array::ArrayView< Value, Rank >

Multi-dimensional access to a Array object or Field object.

An ArrayView enables access to the inner data-memory-storage of the Array. It is required to create the view using the make_view helper functions.

Example 1:

auto view = make_view<double,2>( Array );
double sum = 0;
for( idx_t i=0; i<view.shape(0); ++i ) {
   for( idx_t j=0; j<view.shape(1); ++j ) {
       sum += view(i,j);
   }
}

Data storage

Depending on whether atlas was compiled with the Feature GRIDTOOLS_STORAGE, the internal data allocation of the Array object is managed by GridTools (ATLAS_HAVE_GRIDTOOLS==1) or by Atlas itself (ATLAS_HAVE_GRIDTOOLS==0).

The ArrayView class is therefore also compiled differently dependening on this feature.

Member Function Documentation

contiguous()

template<typename Value, int Rank>

bool atlas::array::ArrayView< Value, Rank >::contiguous ( ) const

inline

Return true when all values are contiguous in memory.

This means that if there is e.g. padding in the fastest dimension, or if the ArrayView represents a slice, the returned value will be false.

operator[]() [1/2]

template<typename Value, int Rank>

template<typename Int , bool EnableBool = true>

std::enable_if<( Rank == 1 && EnableBool ), const value_type&>::type atlas::array::ArrayView< Value, Rank >::operator[] ( Int  idx ) const

inline

Access to data using square bracket [idx] operator {m-label m-warning} Rank==1.

Note that this function is only present when Rank == 1

operator[]() [2/2]

template<typename Value, int Rank>

template<typename Int , bool EnableBool = true>

std::enable_if<( Rank == 1 && EnableBool ), value_type&>::type atlas::array::ArrayView< Value, Rank >::operator[] ( Int  idx )

inline

Access to data using square bracket [idx] operator {m-label m-warning} Rank==1

Note that this function is only present when Rank == 1

shape()

template<typename Value, int Rank>

template<unsigned int Dim>

idx_t atlas::array::ArrayView< Value, Rank >::shape ( ) const

inline

Return number of values in dimension Dim (template argument)

Example use:

for( idx_t i=0; i<view.shape<0>(); ++i ) {
  for( idx_t j=0; j<view.shape<1>(); +j ) {
    ...
  }
}

slice()

template<typename Value, int Rank>

template<typename... Args>

slice_t<Args...>::type atlas::array::ArrayView< Value, Rank >::slice ( Args...  args )

inline

Obtain a slice from this view: view.slice( Range, Range, ...

)

The return type of this function is intentionally auto and is guaranteed to have the same API as ArrayView, but is not necessarily this type.

If the current view has Rank == 2, a Rank == 1 slice can be created in several ways:

auto slice1 = view.slice( Range(0,2), Range::all() );
auto slice2 = view.slice( Range::To(2), Range::all() );

Sometimes it may be required to extend the rank of the current view to cater for certain algorithms requiring an extra rank.

auto slice3 = view.slice( Range::all(), Range::all(), Range::dummy() );

---

The documentation for this class was generated from the following files:

• src/atlas/array/gridtools/GridToolsArrayView.h
• src/atlas/array/native/NativeArrayView.h
• src/atlas/array/gridtools/GridToolsArrayView.cc
• src/atlas/array/native/NativeArrayView.cc