#include <triqs/gfs/gf/gf_view.hpp>

Detailed Description

template<Mesh M, typename Target, typename Layout>
class triqs::gfs::gf_view< M, Target, Layout >

A mutable, non-owning view of a Green's function.

triqs::gfs::gf_view refers to the mesh and data of an existing Green's function (or a slice thereof) without owning them. Assigning to a view writes through to the underlying data. See triqs::gfs::gf for the owning container and triqs::gfs::gf_const_view for the read-only view.

Template Parameters

M	Mesh type, modeling triqs::mesh::Mesh; fixes the domain of definition.
Target	Target type; fixes the value stored at each mesh point.
Layout	Memory layout policy of the data array view.

Definition at line 48 of file gf_view.hpp.

Inheritance diagram for triqs::gfs::gf_view< M, Target, Layout >:

Classes
struct	target_and_shape_t
	Lightweight handle bundling the target type and its shape. More...

Public Types
using	complex_t = gf_view<M, typename Target::complex_t, Layout>
	Associated complex-valued type.
using	const_view_type = gf_const_view<M, Target, Layout>
	Associated const view type.
using	data_t = nda::basic_array_view<scalar_t, data_rank, Layout>
	Type of the data array view.
using	mesh_index_t = typename mesh_t::index_t
	Type of a mesh index.
using	mesh_point_t = typename mesh_t::mesh_point_t
	Type of a mesh point.
using	mesh_t = M
	Mesh type.
using	mutable_view_type = gf_view<M, Target, Layout>
	Associated mutable view type.
using	real_t = gf_view<M, typename Target::real_t, Layout>
	Associated real-valued type.
using	regular_type = gf<M, Target, typename Layout::contiguous_t>
	Associated regular (owning) type.
using	scalar_t = typename Target::scalar_t
	Scalar type of the target (real or complex).
using	target_shape_t = std::array<long, Target::rank>
	Type of the target shape, i.e. an array holding the extent of each target dimension.
using	target_t = Target
	Target type.
using	view_type = gf_view<M, Target, Layout>
	Associated (non const) view type.

Public Member Functions
	gf_view ()=default
	Construct an empty view, not bound to any data.
template<typename L>
	gf_view (gf< M, Target, L > &&g) noexcept
	Construct a view onto an rvalue Green's function.
template<typename L>
	gf_view (gf< M, Target, L > &g)
	Construct a view onto a (non const) Green's function.
template<typename L>
	gf_view (gf< M, Target, L > const &g)=delete
	Deleted: a mutable view cannot be built from a const Green's function.
	gf_view (gf_const_view< M, Target > const &g)=delete
	Deleted: a mutable view cannot be built from a const view.
	gf_view (gf_view &&)=default
	Move constructor.
	gf_view (gf_view const &x)=default
	Copy constructor (shallow: the new view refers to the same data).
	gf_view (mesh_t m, data_t dat)
	Build a view on top of a mesh and a data array.
template<typename Fdata>
auto	apply_on_data (Fdata &&fd)
	Build a view whose data is the result of applying a function to the data array.
template<typename Fdata>
auto	apply_on_data (Fdata &&fd) const
	Build a const view whose data is the result of applying a function to the data array.
data_t &	data () &
	Get the data array view.
data_t	data () &&
	Get the data array view (rvalue overload).
data_t const &	data () const &
	Get the data array view (const overload).
auto const &	data_shape () const
	Get the shape of the data array.
mesh_t const &	mesh () const
	Get the mesh of the Green's function.
template<typename... Args>
decltype(auto)	operator() (Args &&...1) &
	Lvalue overload of the call operator (delegates to call_impl()).
template<typename... Args>
decltype(auto)	operator() (Args &&...1) &&
	Rvalue overload of the call operator (delegates to call_impl()).
template<typename... Args>
decltype(auto)	operator() (Args &&...1) const &
	Const lvalue overload of the call operator (delegates to call_impl()).
gf_view &	operator= (gf_view const &rhs)
	Copy assignment: copy the data through the view without resizing it.
template<typename RHS>
gf_view &	operator= (RHS const &rhs)
	Assign from any compatible right hand side, writing through the view without resizing it.
template<typename... Arg> requires (sizeof...(Arg) == arity)
decltype(auto)	operator[] (Arg &&...arg) &&noexcept(has_no_boundcheck)
	Rvalue overload of the variadic operator[] (see the const lvalue overload).
template<typename... Arg> requires (sizeof...(Arg) == arity)
decltype(auto)	operator[] (Arg &&...arg) &noexcept(has_no_boundcheck)
	Lvalue overload of the variadic operator[] (see the const lvalue overload).
template<typename... Arg> requires (sizeof...(Arg) == arity)
decltype(auto)	operator[] (Arg &&...arg) const &noexcept(has_no_boundcheck)
	Access the Green's function at a mesh point/index (const lvalue overload).
template<typename... T> requires (sizeof...(T) == arity)
decltype(auto)	operator[] (std::tuple< T... > const &tu) const noexcept(has_no_boundcheck)
	Access the Green's function at a mesh point/index passed as a tuple (const overload).
template<typename... T> requires (sizeof...(T) == arity)
decltype(auto)	operator[] (std::tuple< T... > const &tu) noexcept(has_no_boundcheck)
	Non-const overload of the tuple operator[] (see the const overload).
decltype(auto)	operator[] (typename mesh_t::index_t const &index) noexcept(has_no_boundcheck)
	Access a single-variable Green's function by a mesh index.
void	rebind (gf_view< M, Target > const &g) noexcept
	Rebind the view to refer to the mesh and data of another view.
target_and_shape_t	target () const
	Get a handle to the target and its shape.
auto	target_indices () const
	Get a generator over the multi-indices of the target space.
std::array< long, Target::rank >	target_shape () const
	Get the shape of the target.

Static Public Member Functions
template<typename Self, typename... Args>
static decltype(auto)	call_impl (Self &&self, Args &&...1)
	Evaluate the Green's function at the given arguments.
static std::string	hdf5_format ()
	Get the HDF5 format tag of a Green's function.

Static Public Attributes
static constexpr int	arity = n_variables<M>
	Arity of the function, i.e. the number of mesh variables.
static constexpr int	data_rank = arity + Target::rank
	Rank of the data array representing the function (arity + target_rank).
static constexpr bool	has_no_boundcheck = true
	Whether bound checking of the data array is disabled (controlled by NDA_ENFORCE_BOUNDCHECK).
static constexpr bool	is_const = false
	Whether this type is a const view (always false for triqs::gfs::gf_view).
static constexpr bool	is_view = true
	Whether this type is a view (always true for triqs::gfs::gf_view).
static constexpr int	target_rank = Target::rank
	Rank of the target.

Friends
void	h5_read (h5::group fg, std::string const &subgroup_name, this_t &g)
	Read a Green's function from HDF5.
void	h5_write (h5::group fg, std::string const &subgroup_name, this_t const &g)
	Write a Green's function to HDF5.
std::ostream &	operator<< (std::ostream &out, this_t const &)
	Write a Green's function to an output stream.
void	swap (gf_view &a, gf_view &b) noexcept
	Swap two views.

Constructor & Destructor Documentation

◆ gf_view() [1/4]

template<Mesh M, typename Target, typename Layout>

triqs::gfs::gf_view< M, Target, Layout >::gf_view ( gf_view< M, Target, Layout > const & x )

default

Copy constructor (shallow: the new view refers to the same data).

Parameters

x	View to copy from.

◆ gf_view() [2/4]

template<Mesh M, typename Target, typename Layout>

template<typename L>

triqs::gfs::gf_view< M, Target, Layout >::gf_view ( gf< M, Target, L > & g )

inline

Construct a view onto a (non const) Green's function.

Template Parameters

L	Layout of the Green's function.

Parameters

g	Green's function to view.

Definition at line 213 of file gf_view.hpp.

◆ gf_view() [3/4]

template<Mesh M, typename Target, typename Layout>

template<typename L>

triqs::gfs::gf_view< M, Target, Layout >::gf_view ( gf< M, Target, L > && g )

inlinenoexcept

Construct a view onto an rvalue Green's function.

Template Parameters

L	Layout of the Green's function.

Parameters

g	Green's function to view.

Definition at line 221 of file gf_view.hpp.

◆ gf_view() [4/4]

template<Mesh M, typename Target, typename Layout>

triqs::gfs::gf_view< M, Target, Layout >::gf_view	(	mesh_t	m,
		data_t	dat )

inline

Build a view on top of a mesh and a data array.

Parameters

m	Mesh.
dat	Data array (view).

Definition at line 229 of file gf_view.hpp.

Member Function Documentation

◆ apply_on_data() [1/2]

template<Mesh M, typename Target, typename Layout>

template<typename Fdata>

auto triqs::gfs::gf_view< M, Target, Layout >::apply_on_data ( Fdata && fd )

inline

Build a view whose data is the result of applying a function to the data array.

Template Parameters

Fdata Type of the callable applied to the data array.

Parameters

fd	Callable taking the data array and returning a transformed array.

Returns: A triqs::gfs::gf_view onto the transformed data, sharing this view's mesh.

Definition at line 289 of file gf_view.hpp.

◆ apply_on_data() [2/2]

template<Mesh M, typename Target, typename Layout>

template<typename Fdata>

auto triqs::gfs::gf_view< M, Target, Layout >::apply_on_data ( Fdata && fd ) const

inline

Build a const view whose data is the result of applying a function to the data array.

Template Parameters

Fdata Type of the callable applied to the data array.

Parameters

fd	Callable taking the data array and returning a transformed array.

Returns: A triqs::gfs::gf_const_view onto the transformed data, sharing this view's mesh.

Definition at line 303 of file gf_view.hpp.

◆ call_impl()

template<Mesh M, typename Target, typename Layout>

template<typename Self, typename... Args>

decltype(auto) triqs::gfs::gf_view< M, Target, Layout >::call_impl	(	Self &&	self,
		Args &&...	1 )

inlinestatic

Evaluate the Green's function at the given arguments.

With no argument, returns a (const) view of the whole Green's function. Otherwise, the number of arguments must equal the arity of the mesh; if any argument is a lazy CLEF expression a lazy call expression is returned, else the Green's function is evaluated using the mesh's interpolation scheme (triqs::gfs::gf_evaluator).

Template Parameters

Self	Deduced (explicit object parameter) type of the Green's function.
Args	Types of the evaluation arguments (one per mesh dimension).

Returns: A view (no argument), a lazy expression (lazy arguments) or the interpolated value.

Definition at line 49 of file gf_view.hpp.

◆ data() [1/3]

template<Mesh M, typename Target, typename Layout>

data_t & triqs::gfs::gf_view< M, Target, Layout >::data ( ) &

inline

Get the data array view.

Returns: A reference to the data array view.

Definition at line 131 of file gf_view.hpp.

◆ data() [2/3]

template<Mesh M, typename Target, typename Layout>

data_t triqs::gfs::gf_view< M, Target, Layout >::data ( ) &&

inline

Get the data array view (rvalue overload).

Returns: The data array view, moved out of the (expiring) view.

Definition at line 143 of file gf_view.hpp.

◆ data() [3/3]

template<Mesh M, typename Target, typename Layout>

data_t const & triqs::gfs::gf_view< M, Target, Layout >::data ( ) const &

inline

Get the data array view (const overload).

Returns: A const reference to the data array view.

Definition at line 137 of file gf_view.hpp.

◆ data_shape()

template<Mesh M, typename Target, typename Layout>

auto const & triqs::gfs::gf_view< M, Target, Layout >::data_shape ( ) const

inline

Get the shape of the data array.

Needed for generic code: expressions of Green's functions (e.g. g1 + g2) have a data shape but no data array.

Returns: A const reference to the shape of the data array.

Definition at line 153 of file gf_view.hpp.

◆ hdf5_format()

template<Mesh M, typename Target, typename Layout>

std::string triqs::gfs::gf_view< M, Target, Layout >::hdf5_format ( )

inlinestaticnodiscard

Get the HDF5 format tag of a Green's function.

Returns: The string "Gf".

Definition at line 210 of file gf_view.hpp.

◆ mesh()

template<Mesh M, typename Target, typename Layout>

mesh_t const & triqs::gfs::gf_view< M, Target, Layout >::mesh ( ) const

inline

Get the mesh of the Green's function.

Returns: A const reference to the mesh.

Definition at line 125 of file gf_view.hpp.

◆ operator=() [1/2]

template<Mesh M, typename Target, typename Layout>

gf_view & triqs::gfs::gf_view< M, Target, Layout >::operator= ( gf_view< M, Target, Layout > const & rhs )

inline

Copy assignment: copy the data through the view without resizing it.

Warning: If the size of this is not the same as rhs, the behaviour is undefined.

Parameters

rhs	View to copy from.

Returns: A reference to this view.

Definition at line 259 of file gf_view.hpp.

◆ operator=() [2/2]

template<Mesh M, typename Target, typename Layout>

template<typename RHS>

gf_view & triqs::gfs::gf_view< M, Target, Layout >::operator= ( RHS const & rhs )

inline

Assign from any compatible right hand side, writing through the view without resizing it.

rhs can be a scalar (assigned to every mesh point) or any Green's function (object/view/expression) with the same mesh.

Template Parameters

RHS	Type of the right hand side.

Parameters

rhs	Object to assign from.

Returns: A reference to this view.

Definition at line 274 of file gf_view.hpp.

◆ operator[]() [1/3]

template<Mesh M, typename Target, typename Layout>

template<typename... Arg>
requires (sizeof...(Arg) == arity)

decltype(auto) triqs::gfs::gf_view< M, Target, Layout >::operator[] ( Arg &&... arg ) const &

inlinenoexcept

Access the Green's function at a mesh point/index (const lvalue overload).

Unlike operator(), this accesses the stored value directly (no interpolation). Passing all_t for one or more dimensions returns a (const) view sliced over the remaining mesh, and lazy arguments return a lazy subscript expression.

Template Parameters

Arg	Types of the access arguments (one per mesh dimension).

Parameters

arg	Mesh points, indices or all_t selectors.

Returns: The stored value, a sliced view, or a lazy expression.

Definition at line 170 of file gf_view.hpp.

◆ operator[]() [2/3]

template<Mesh M, typename Target, typename Layout>

template<typename... T>
requires (sizeof...(T) == arity)

decltype(auto) triqs::gfs::gf_view< M, Target, Layout >::operator[] ( std::tuple< T... > const & tu ) const

inlinenoexcept

Access the Green's function at a mesh point/index passed as a tuple (const overload).

Flattens the tuple into the variadic operator[]. Ensures backward compatibility and easy use when the arguments are stored in a tuple.

Template Parameters

T	Types of the tuple elements (one per mesh dimension).

Parameters

tu	Tuple of mesh points/indices.

Returns: The value (or sub-view) at the given point.

Definition at line 93 of file gf_view.hpp.

◆ operator[]() [3/3]

template<Mesh M, typename Target, typename Layout>

decltype(auto) triqs::gfs::gf_view< M, Target, Layout >::operator[] ( typename mesh_t::index_t const & index )

inlinenoexcept

Access a single-variable Green's function by a mesh index.

Parameters

index Mesh index.

Returns: The stored value at the corresponding mesh point.

Definition at line 198 of file gf_view.hpp.

◆ rebind()

template<Mesh M, typename Target, typename Layout>

void triqs::gfs::gf_view< M, Target, Layout >::rebind ( gf_view< M, Target > const & g )

inlinenoexcept

Rebind the view to refer to the mesh and data of another view.

Parameters

g	View to rebind onto.

Definition at line 245 of file gf_view.hpp.

◆ target()

template<Mesh M, typename Target, typename Layout>

target_and_shape_t triqs::gfs::gf_view< M, Target, Layout >::target ( ) const

inline

Get a handle to the target and its shape.

Returns: A triqs::gfs::gf_view::target_and_shape_t bundling the target type and shape (mesh dimensions dropped).

Definition at line 159 of file gf_view.hpp.

◆ target_indices()

template<Mesh M, typename Target, typename Layout>

auto triqs::gfs::gf_view< M, Target, Layout >::target_indices ( ) const

inline

Get a generator over the multi-indices of the target space.

Returns: A range iterating over all index tuples of the target.

Definition at line 171 of file gf_view.hpp.

◆ target_shape()

template<Mesh M, typename Target, typename Layout>

std::array< long, Target::rank > triqs::gfs::gf_view< M, Target, Layout >::target_shape ( ) const

inline

Get the shape of the target.

Returns: An array holding the extent of each target dimension.

Definition at line 165 of file gf_view.hpp.

◆ h5_read

template<Mesh M, typename Target, typename Layout>

void h5_read	(	h5::group	fg,
		std::string const &	subgroup_name,
		this_t &	g )

friend

Read a Green's function from HDF5.

Throws a triqs::runtime_error if the HDF5 format tag does not correspond to a Green's function.

Parameters

fg	h5::group to read from.
subgroup_name	Name of the subgroup to read.
g	Green's function to read into.

Definition at line 237 of file gf_view.hpp.

◆ h5_write

template<Mesh M, typename Target, typename Layout>

void h5_write	(	h5::group	fg,
		std::string const &	subgroup_name,
		this_t const &	g )

friend

Write a Green's function to HDF5.

Parameters

fg	h5::group to write into.
subgroup_name	Name of the subgroup to create.
g	Green's function to write.

Definition at line 222 of file gf_view.hpp.

◆ operator<<

template<Mesh M, typename Target, typename Layout>

std::ostream & operator<<	(	std::ostream &	out,
		this_t const &	)

friend

Write a Green's function to an output stream.

Parameters

out	std::ostream output stream.

Returns: Reference to the output stream.

Definition at line 253 of file gf_view.hpp.

◆ swap

template<Mesh M, typename Target, typename Layout>

void swap	(	gf_view< M, Target, Layout > &	a,
		gf_view< M, Target, Layout > &	b )

friend

Swap two views.

Parameters

a	First view.
b	Second view.

Definition at line 238 of file gf_view.hpp.

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

triqs/gfs/gf/gf.hpp
triqs/gfs/gf/gf_view.hpp

Detailed Description

Classes

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Friends

Constructor & Destructor Documentation

◆ gf_view() [1/4]

◆ gf_view() [2/4]

◆ gf_view() [3/4]

◆ gf_view() [4/4]

Member Function Documentation

◆ apply_on_data() [1/2]

◆ apply_on_data() [2/2]

◆ call_impl()

◆ data() [1/3]

◆ data() [2/3]

◆ data() [3/3]

◆ data_shape()

◆ hdf5_format()

◆ mesh()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator[]() [1/3]

◆ operator[]() [2/3]

◆ operator[]() [3/3]

◆ rebind()

◆ target()

◆ target_indices()

◆ target_shape()

Friends And Related Symbol Documentation

◆ h5_read

◆ h5_write

◆ operator<<

◆ swap