Collaboration diagram for Nexus Algorithms:

Modules
	Internal classes used by algorithms

Functions
template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
ATYPE	pni::io::nx::as_attribute (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	as attribute wrapper More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
FTYPE	pni::io::nx::as_field (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	as field wrapper More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
GTYPE	pni::io::nx::as_group (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	as group wrapper More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
LTYPE	pni::io::nx::as_link (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	as link wrapper More...

template<nximp_code IMPID>
void	pni::io::nx::close (nxlink< IMPID > &)
	close object More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
void	pni::io::nx::close (nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	close object More...

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename STYPE >
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::create_attribute (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &parent, const pni::core::string &name, const STYPE &shape, bool overwrite=false)
	create multidimensional attribute More...

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::create_attribute (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &parent, const pni::core::string &name, bool overwrite=false)
	create scalar attribute More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename... ARGTS>
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::create_attribute (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o, pni::core::type_id_t tid, ARGTS...args)
	create attribute More...

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename STYPE , typename FILTERT , typename PATHT >
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::create_field (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &location, const PATHT &path, const STYPE &shape, const STYPE &chunk, const FILTERT &filter)
	field construction More...

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename STYPE , typename PATHT >
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::create_field (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &parent, const PATHT &path, const STYPE &shape, const STYPE &chunk)
	field construction template More...

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename STYPE , typename PATHT , typename FILTERIMP >
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::create_field (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &parent, const PATHT &path, const STYPE &shape, const nxfilter< FILTERIMP > &filter)
	field construction template More...

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename PATHT , typename STYPE = pni::core::shape_t>
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::create_field (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &parent, const PATHT &path, const STYPE &shape={1})
	field construction template More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename... ARGTS>
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::create_field (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o, pni::core::type_id_t tid, ARGTS...args)
	field construction template More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename PATHT >
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::create_group (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o, const PATHT &path)
	create_group wrapper More...

template<template< nximp_code > class PTYPE, nximp_code IMPID>
nxobject_trait< IMPID > ::object_type	pni::io::nx::get_attribute (const PTYPE< IMPID > &parent, const pni::core::string &name)
	get attribute by name More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::get_attribute (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &parent, const pni::core::string &name)
	get attribute More...

template<typename CTYPE , template< nximp_code > class PTYPE, nximp_code IMPID>
CTYPE	pni::io::nx::get_attributes (const PTYPE< IMPID > &parent)
	get attributes from an object More...

template<typename CTYPE , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
CTYPE	pni::io::nx::get_attributes (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &parent)
	get attributes More...

template<typename OTYPE >
auto	pni::io::nx::get_child (const OTYPE &o, const pni::core::string &n, const pni::core::string &c="") -> decltype(get_parent(o))
	get child by name and/or class More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
auto	pni::io::nx::get_child (const OTYPE< IMPID > &parent, size_t index) -> decltype(get_parent(parent))
	get child by index More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
auto	pni::io::nx::get_child (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &parent, size_t index) -> decltype(get_parent(parent))
	get child by index More...

template<typename CTYPE , typename OTYPE >
CTYPE	pni::io::nx::get_children (const OTYPE &parent, const string &c)
	get children with a common class More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
pni::core::string	pni::io::nx::get_class (const OTYPE< IMPID > &group)
	get the class of a group More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
pni::core::string	pni::io::nx::get_class (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get group class More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
pni::core::string	pni::io::nx::get_filename (const OTYPE< IMPID > &o)
	get filename More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
pni::core::string	pni::io::nx::get_filename (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get filename More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
pni::core::string	pni::io::nx::get_name (const OTYPE< IMPID > &o)
	get object name More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
pni::core::string	pni::io::nx::get_name (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get name More...

template<typename OTYPE , typename PATHT >
auto	pni::io::nx::get_object (const OTYPE &o, const PATHT &path) -> decltype(get_parent(o))
	retrieve an object from path More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
nxobject_trait< IMPID > ::object_type	pni::io::nx::get_parent (const OTYPE< IMPID > &o)
	return parent More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
nxobject< GTYPE, FTYPE, ATYPE, LTYPE >	pni::io::nx::get_parent (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get parent More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
pni::core::string	pni::io::nx::get_path (const OTYPE< IMPID > &o)
	get object path More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
pni::core::string	pni::io::nx::get_path (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get path More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
size_t	pni::io::nx::get_rank (const OTYPE< IMPID > &o)
	get rank More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
size_t	pni::io::nx::get_rank (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get rank More...

template<typename OTYPE >
auto	pni::io::nx::get_root (const OTYPE &p) -> decltype(get_parent(p))
	get root More...

template<typename CTYPE , template< nximp_code > class OTYPE, nximp_code IMPID>
CTYPE	pni::io::nx::get_shape (const OTYPE< IMPID > &object)
	get shape More...

template<typename CTYPE , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
CTYPE	pni::io::nx::get_shape (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get shape More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
size_t	pni::io::nx::get_size (const OTYPE< IMPID > &o)
	get number of elements More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
size_t	pni::io::nx::get_size (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get size More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
pni::core::type_id_t	pni::io::nx::get_type (const OTYPE< IMPID > &o)
	get type More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
pni::core::type_id_t	pni::io::nx::get_type (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get type More...

template<typename FTYPE >
pni::core::string	pni::io::nx::get_unit (const FTYPE &field)
	get the unit of a field More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
void	pni::io::nx::grow (OTYPE< IMPID > &o, size_t dimension=0, size_t extend=1)
	grow a field More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
void	pni::io::nx::grow (nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o, size_t d=0, size_t e=1)
	grow object More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
bool	pni::io::nx::is_attribute (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o) noexcept
	check if attribute More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
bool	pni::io::nx::is_class (const OTYPE< IMPID > &object, const pni::core::string &type)
	checks group type More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
bool	pni::io::nx::is_class (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o, const pni::core::string &c)
	is class function More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
bool	pni::io::nx::is_field (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o) noexcept
	check if field More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
bool	pni::io::nx::is_group (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o) noexcept
	test for group More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
bool	pni::io::nx::is_link (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o) noexcept
	test for group More...

template<typename OTYPE >
bool	pni::io::nx::is_valid (const OTYPE &o) noexcept
	visitor checking object validity More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
bool	pni::io::nx::is_valid (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o) noexcept
	is_valid wrapper More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
auto	pni::io::nx::begin (const OTYPE< IMPID > &group) -> decltype(group.begin())
	get iterator to first element More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
auto	pni::io::nx::end (const OTYPE< IMPID > &group) -> decltype(group.end())
	get iterator to last element More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
GTYPE::iterator	pni::io::nx::begin (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get iterator to first child More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
GTYPE::iterator	pni::io::nx::end (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o)
	get iterator to last+1 child More...

template<typename OTYPE >
OTYPE	pni::io::nx::get_object_by_name (const OTYPE &parent, const pni::core::string &name)
	search for object by name More...

template<typename OTYPE >
OTYPE	pni::io::nx::get_object_by_name_and_class (const OTYPE &parent, const pni::core::string &name, const pni::core::string &c)
	search for object by name and class More...

template<typename OTYPE >
OTYPE	pni::io::nx::get_object_by_class (const OTYPE &parent, pni::core::string c)
	find object by class More...

template<template< nximp_code > class OTYPE, nximp_code IMPID, typename ATYPE >
void	pni::io::nx::read (const OTYPE< IMPID > &o, ATYPE &a)
	read data More...

template<template< nximp_code > class OTYPE, nximp_code IMPID, typename ATYPE , typename... ITYPES>
void	pni::io::nx::read (const OTYPE< IMPID > &o, ATYPE &a, ITYPES...indices)
	read data More...

template<typename ATYPE , typename GTYPE , typename FTYPE , typename ATTYPE , typename LTYPE , typename... ITYPES>
void	pni::io::nx::read (const nxobject< GTYPE, FTYPE, ATTYPE, LTYPE > &o, ATYPE &a, ITYPES...indices)
	read data from a field or attribute More...

template<typename ATYPE , typename GTYPE , typename FTYPE , typename ATTYPE , typename LTYPE >
void	pni::io::nx::read (const nxobject< GTYPE, FTYPE, ATTYPE, LTYPE > &o, ATYPE &a, const std::vector< pni::core::slice > &sel)
	read data from a field or attribute More...

template<template< nximp_code > class OTYPE, nximp_code IMPID>
void	pni::io::nx::set_class (const OTYPE< IMPID > &o, const pni::core::string &nxclass)
	set class for a group More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
void	pni::io::nx::set_class (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o, const pni::core::string &c)
	set class More...

template<typename FTYPE >
void	pni::io::nx::set_unit (const FTYPE &field, const pni::core::string &value)
	set the unit More...

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >
void	pni::io::nx::set_unit (const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &o, const pni::core::string &s)
	set unit More...

template<template< nximp_code > class OTYPE, nximp_code IMPID, typename ATYPE >
void	pni::io::nx::write (const OTYPE< IMPID > &o, const ATYPE &a)
	write data to an attribute or field More...

template<template< nximp_code > class OTYPE, nximp_code IMPID, typename ATYPE , typename... ITYPES>
void	pni::io::nx::write (const OTYPE< IMPID > &o, const ATYPE &a, ITYPES...indices)
	write data to an attribute or field More...

template<typename ATYPE , typename GTYPE , typename FTYPE , typename AATYPE , typename LTYPE , typename... ITYPES>
void	pni::io::nx::write (nxobject< GTYPE, FTYPE, AATYPE, LTYPE > &&o, const ATYPE &a, ITYPES...indices)
	write wrapper More...

Detailed Description

Nexus files can be considered as a heterogeneous container (a container holding instances of different types). This section describes algorithms that work on particular Nexus objects.

There are basically three kinds of algorithms

general purpose algorithms that can be applied to all objects
algorithms related to the group type
algorithms related to IO types like fields and attributes

General purpose algorithms are

function name	purpose	principal input	return type
as_attribute	convert nxobject to nxattribute	nxobject	nxattribute
as_field	convert nxobject to nxfield	nxobject	nxfield
as_group	convert nxobject to nxgroup	nxobject	nxgruop
is_attribute	true if object is an nxattribute	nxobject	bool
is_field	true if object is an nxfield	nxobject	bool
is_group	true if object is an nxgroup	nxobject	bool
is_valid	true if object is valid	all	bool
get_name	return the name of an object	all	string
colse	close an object	all	void
create_attribute	create an attribute	nxobject, nxfield, nxgroup	nxobject
get_attribute	return an attribute	nxobject, nxfield, nxgruop	nxobject
get_attributes	return attribute container	nxfield,nxgroup,nxobject	container<nxobject>
get_parent	get parent object	all	nxobject
get_path	get path	all	nxpath
get_root	return root group	all	nxobject

Group related algorithms are

function name	purpose	principal input	return type
get_child_by_index	return child by numeric index	nxgroup, nxobject	nxobject
get_child	return child by name	nxgroup, nxobject	nxobject
get_children	returns list of children	nxgroup, nxobject	container
get_object	get object by path	nxgroup, nxobject	nxobject
create_field	create a field	nxgroup, nxobject	nxobject
create_group	create a group	nxgroup, nxobject	nxobject
get_class	return a groups class	nxgroup, nxobject	string
is_class	check if object is of a particular class	nxgroup,nxobject	bool
set_class	set the class of an object	nxgruop, nxobject	void

IO (nxattribute, nxfield) related algorithms

function name	purpose	principal input	return type
get_shape	return object shape	nxfield, nxattribute, nxobject	container
get_size	return size of element	nxfield, nxattribute, nxobject	size_t
get_type	get type ID of the object	nxfield, nxattribute, nxobject	type_id_t
get_unit	return unit of data field	nxfield, nxobject	string
set_unit	set unit for a field	nxfield, nxobject	void
get_rank	return number of dimensions	nxfield, nxattribute, nxobject	size_t
grow	grow a field	nxfield, nxobject	void
read	read data from object	nxfield, nxattribute, nxobject	void
write	write data to object	nxfield, nxattribute, nxobject	void

Function Documentation

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

ATYPE pni::io::nx::as_attribute ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Function template extracting an attribute stored in an nxobject instance. If the object is not an attribute an nxattribute_error exception will be thrown. The object is returned as an nxattribute instance.

auto attr_obj = get_object(root,path_to_atribute);

auto a = as_attribute(attr_obj);

Exceptions

type_error if stored object is not a attribute type

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type

Parameters

o	instance of nxobject

Returns: instance of ATYPE

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

FTYPE pni::io::nx::as_field ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

function template extracting a field stored in an nxobject instance. If the stored object is not an instance of nxfield an exception of type nxfield_error will be thrown.

auto object = get_object(root,path_to_field);

auto field = as_field(field_obj);

Exceptions

type_error if stored object is not a field type

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type

Parameters

o	instance of nxobject

Returns: instance of FTYPE

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

GTYPE pni::io::nx::as_group ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Function template returning a group object stored in an nxobject instance. If the stored object is not an instance of nxgroup an exception will be thrown.

auto object = get_object(root,path_to_group);

auto group = as_group(group_obj);

Exceptions

type_error if stored object is not a group type

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type

Parameters

o	instance of nxobject<GTYPE,FTYPE,ATYPE>

Returns: instance of GTYPE

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

LTYPE pni::io::nx::as_link ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Function template extracting a link stored in an nxobject instance. If the object is not a link a type_error exception will be thrown. The object is returned as an nxlink instance.

auto link_obj = get_object(root,path_to_link);

auto l = as_link(link_obj);

Exceptions

type_error if stored object is not a attribute type

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject

Returns: instance of ATYPE

template<template< nximp_code > class OTYPE, nximp_code IMPID>

auto pni::io::nx::begin ( const OTYPE< IMPID > & group ) -> decltype(group.begin())

Returns an iterator to the first child element of a group object.

Parameters

group reference to a group instance

Returns: iterator to first child

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

GTYPE::iterator pni::io::nx::begin ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Returns an iterator to the first child attached to a group stored in an nxobject instance. If the nxobject instance does not hold a group type_error is thrown.

Exceptions

type_error if the stored object is not a group

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	group object

Returns: iterator to the first child

template<nximp_code IMPID>

void pni::io::nx::close ( nxlink< IMPID > & )

Invokes the close() method of the passed object. The objects accepted by this function template are either of type nxfield, nxattribute, nxgroup, or nxfile.

Exceptions

object_error	in case of errors
type_error	if internal object type is not supported

Template Parameters

OTYPE object type

Parameters

o	instance of the object to close

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

void pni::io::nx::close ( nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Wrapper function around the close_visitor. The function closes the object stored in the variant type passed to it.

Exceptions

object_error	in case of an error during closing the object
type_error	if the internal object type could not be determined

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject<GTYPE,FTYPE,ATYPE,LTYPE>

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename STYPE >

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::create_attribute	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	parent,
		const pni::core::string &	name,
		const STYPE &	shape,
		bool	overwrite = `false`
	)

Create an attribute of a particular name, type, and shape at a parent object. The parent is provided as an instance of nxobject.

auto g = get_object(...);

auto attr = create_attribute<int32>(g,"test",shape_t{4,4});

The last argument is the shape of the attribute. If now shape is passed a scalar attribute will be created.

Exceptions

invalid_object_error	if the parent object is not valid
type_error	if the data type is not supported or the parent holds an nxattribute instance
object_error	in case of any other error

Template Parameters

T	data type of the attribute
GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type
STYPE	shape container type

Parameters

parent	instance of parent object
name	name of the new attribute
shape	shape of the attribute
overwrite	if true an existing attribute will be overwritten

Returns: attribute as an instance of nxobject

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::create_attribute	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	parent,
		const pni::core::string &	name,
		bool	overwrite = `false`
	)

Create an attribute of a particular name, type, and shape at a parent object. The parent is provided as an instance of nxobject.

auto g = get_object(...);

auto attr = create_attribute<int32>(g,"test",shape_t{4,4});

The last argument is the shape of the attribute. If now shape is passed a scalar attribute will be created.

Exceptions

invalid_object_error	if the parent object is not valid
type_error	if the data type is not supported or the parent holds an nxattribute instance
object_error	in case of any other error

Template Parameters

T	data type of the attribute
GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

parent	instance of the parent
name	name of the new attribute
overwrite	if true overwrite an existing attribute of equal name

Returns: attribute as an instance of nxobject

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename... ARGTS>

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::create_attribute	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	o,
		pni::core::type_id_t	tid,
		ARGTS...	args
	)

Create an attribute of a given name, shape, and type at a parent object. This special version of create_attribute is particularly useful in situations where the data type is provided at runtime.

auto parent = get_object(...);
string name = get_name_from_user(...);
type_id_t tid = get_type_from_user(...);
auto attr = create_attribute(parent,tid,name);

The first two arguments are the parent object and the type id. All other arguments are the same as for the other create_attribute templates.

Exceptions

invalid_object_error	if the parent object is not valid
type_error	if the data type is not supported or the parent holds an nxattribute instance
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type
STYPE	shape container type

Parameters

o	instance of VTYPE with the parent group
tid	type id of the attributes data type
args	residual arguments

Returns: newly created attribute as an instance of nxobject

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename STYPE , typename FILTERT , typename PATHT >

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::create_field	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	location,
		const PATHT &	path,
		const STYPE &	shape,
		const STYPE &	chunk,
		const FILTERT &	filter
	)

The full function to construct a field relative to a particular group.

Exceptions

invalid_object_error	if the parent is not valid
type_error	if the data type is not supported
size_mismatch_error	if chunk-shape and shape do not match
object_error	in case of any other error

Template Parameters

T	data type of the new array
GTYPE	group type
FTYPE	field type
ATYPE	attribute type
STYPE	shape type
FILTERT	filter type
PATHT	path type

Parameters

location	the root location where the field should be created
path	a string or nxpath object with the path to the field
shape	the initial shape of the field
chunk	the chunkd shape of the field
filter	reference to the filter object

Returns: field type wrapped into an nxobject instance

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename STYPE , typename PATHT >

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::create_field	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	parent,
		const PATHT &	path,
		const STYPE &	shape,
		const STYPE &	chunk
	)

This template does field construction without filters

Exceptions

invalid_object_error	if the parent is not valid
type_error	if the data type is not supported
size_mismatch_error	if chunk-shape and shape do not match
object_error	in case of any other error

Template Parameters

T	data type of the new field
GTYPE	group type
FTYPE	field type
ATYPE	attribute type
STYPE	shape type
PATHT	path type

Parameters

parent	the parent object for the field
path	string or nxpath with the location of the field
shape	the shape of the field
chunk	the chunk shape for the field

Returns: field type wrapped into an nxobject instance

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename STYPE , typename PATHT , typename FILTERIMP >

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::create_field	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	parent,
		const PATHT &	path,
		const STYPE &	shape,
		const nxfilter< FILTERIMP > &	filter
	)

This template does field construction with filters. Only the primary shape of the field is given by the user. The chunk shape will be created automatically.

Exceptions

invalid_object_error	if the parent is not valid
type_error	if the data type is not supported
size_mismatch_error	if chunk-shape and shape do not match
object_error	in case of any other error

Template Parameters

T	data type of the new field
GTYPE	group type
FTYPE	field type
ATYPE	attribute type
STYPE	shape type
PATHT	path type
FILTERIMP	filter implementation type

Parameters

parent	the parent object for the field
path	string or nxpath with the location of the field
shape	the shape of the field
filter	reference to the filter to use

Returns: field type wrapped into an nxobject instance

template<typename T , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename PATHT , typename STYPE = pni::core::shape_t>

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::create_field	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	parent,
		const PATHT &	path,
		const STYPE &	shape = `{1}`
	)

Exceptions

invalid_object_error	if the parent is not valid
type_error	if the data type is not supported
size_mismatch_error	if chunk-shape and shape do not match
object_error	in case of any other error

Template Parameters

T	data type of the new field
GTYPE	group type
FTYPE	field type
ATYPE	attribute type
PATHT	path type
STYPE	shape type

Parameters

parent	the parent location for the new field
path	string or nxpath with the relative position for the field
shape	the shape of the new field

Returns: field type wrapped into an nxobject instance

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename... ARGTS>

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::create_field	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	o,
		pni::core::type_id_t	tid,
		ARGTS...	args
	)

This template function is particulary useful if the data type for the new field is available only at runtime.

Exceptions

invalid_object_error	if the parent is not valid
type_error	if the data type is not supported
size_mismatch_error	if chunk-shape and shape do not match
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
ARGTS	residual argument types

Parameters

o	parent location for the new field
tid	the type ID for the new field
args	residual args as for the other function templates

Returns: field type wrapped into an nxobject instance

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE , typename PATHT >

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::create_group	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	o,
		const PATHT &	path
	)

Wrapper function for the create_group_visitor. This wrapper creates a new group of a particular name and class directly below the parent group. In order to successfully create a group at least the name argument must be non-empty. If an empty string is passed as the groups class then the NX_class attribute will not be set. The function does not create intermediate groupw which do not exist. In this case an key_error exception will be thrown.

Exceptions

invalid_object_error	if the parent is not valid
key_error	if an element in the path provided by the user does not exist
type_error	if the parent object is not a group
object_error	in case of any other error
value_error	if the user did not provide a name for the new group
io_error	if metadata retrieval failed

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type
PATHT	path type

Parameters

o	reference to the parent
path	the path or name of the new group

Returns: object_types with the newly created group

template<template< nximp_code > class OTYPE, nximp_code IMPID>

auto pni::io::nx::end ( const OTYPE< IMPID > & group ) -> decltype(group.end())

Returns an iterator to the last+1 child of a group.

Parameters

group reference to the group instance

Returns: iterator to last+1 element

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

GTYPE::iterator pni::io::nx::end ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Return an interator to the last+1 child attached to a group stored in an instance of nxobject or throw type_error if the nxobject instance does not hold a gruop.

Exceptions

type_error if the stored object is not a group

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	the group from which we want the iterator

Returns: iterator to last+1 child

template<template< nximp_code > class PTYPE, nximp_code IMPID>

nxobject_trait<IMPID>::object_type pni::io::nx::get_attribute	(	const PTYPE< IMPID > &	parent,
		const pni::core::string &	name
	)

Return an attribute from a parent object. This template will work for the following types

nxfield
nxgroup

Exceptions

invalid_object_error	if parent is not valid
key_error	if the object does not have an attribute with name
object_error	in case of any other erro

Template Parameters

PTYPE	parent type template
IMPID	parent type implementation id

Parameters

parent	refernece to parent instance
name	attributes name

Returns: attribute type

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::get_attribute	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	parent,
		const pni::core::string &	name
	)

Returns an attribute from an object stored in an instance of nxobject. The object must be either an nxfield or an nxgroup instance.

Exceptions

invalid_object_error	if the parent is not valid
key_error	if the attribute does not exist
type_error	if the parent is not a field or group
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

parent	reference to the parent object
name	the attributes name

Returns: attribute as an object_types variant

template<typename CTYPE , template< nximp_code > class PTYPE, nximp_code IMPID>

CTYPE pni::io::nx::get_attributes ( const PTYPE< IMPID > & parent )

Return a container with all attributes attached to an object. The value type of the container must either be an instance of nxobject or nxattribute (otherwise a compile time assertion will be raised).

This template will retrieve the attributes from the following types

nxfield
nxgroup

Exceptions

object_error in case of any other erro

Template Parameters

CTYPE	container type where to store the attributes
PTYPE	parent type template
IMPID	parent type implementation id

Parameters

parent reference to parent instance

Returns: instance of CTYPE with attributes

template<typename CTYPE , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

CTYPE pni::io::nx::get_attributes ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & parent )

Return all attributes attached to an object in an instance of a ser defined container type.

Exceptions

invalid_object_error	if the parent is not valid
object_error	in case of any other error

Template Parameters

CTYPE	container type
GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

parent reference to the parent object

Returns: attribute as an object_types variant

template<typename OTYPE >

auto pni::io::nx::get_child	(	const OTYPE &	o,
		const pni::core::string &	n,
		const pni::core::string &	c = `""`
	)		-> decltype(get_parent(o))

Returns the child of a group which is determined by its name and/or group.

Exceptions

invalid_object_error	if the parent is not valid
type_error	if the object is not an nxgroup instance or the nxobject instance does not store a group
key_error	if an object which satisifies the requested name and class could not be found
object_error	in case of any other error

Template Parameters

OTYPE group or nxobject instance

Parameters

o	nxgroup or nxobject instance
n	name of the child
c	class of the object

Returns: child as instance of nxobject

template<template< nximp_code > class OTYPE, nximp_code IMPID>

auto pni::io::nx::get_child	(	const OTYPE< IMPID > &	parent,
		size_t	index
	)		-> decltype(get_parent(parent))

Get a child by its numerical index. The parent object is an instance of nxgroup.

Exceptions

invalid_object_error	if the parent is not valid
index_error	if index exceeds total number of children
type_error	if the type of a child is not supported
object_error	in case of any other error

Template Parameters

OTYPE	object template
IMPID	implementation ID

Parameters

parent	instance of the parent object
index	numerical index of the requested child

Returns: child instance as nxobject

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

auto pni::io::nx::get_child	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	parent,
		size_t	index
	)		-> decltype(get_parent(parent))

This template function takes an instance of nxobject wrapping a group as a parent. If the wrapped object is not a group a type_error exception is thrown.

Exceptions

invalid_object_error	if the parent is not valid
index_error	if the index exceeds the total number of children
type_error	if the parent is not a group or the child type is not supported
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

parent	instance of nxobject with the parent group
index	the numerical index of the requested child

Returns: child instance as nxobject

template<typename CTYPE , typename OTYPE >

CTYPE pni::io::nx::get_children	(	const OTYPE &	parent,
		const string &	c
	)

Returns all children of a parent group which share a common class type. The results will be stored in a container type provided by the user as a template paremeter. It is important to note that the only parameter we can search for here is the base class type. As we are searching only within a single parent all names must be distinct. Unlike the get_cild function template this template does not throw if no object matches the class type. Instead, an empty container is returned.

Exceptions

invalid_object_error	if the parent is not valid
type_error	if the object is not an nxgroup instance or the nxobject instance does not store a group
object_error	in case of any other error

Template Parameters

CTYPE	container type to hold the results
OTYPE	group or nxobject instance

Parameters

o	nxgroup or nxobject instance
c	class of the object

Returns: child as instance of nxobject

template<template< nximp_code > class OTYPE, nximp_code IMPID>

pni::core::string pni::io::nx::get_class ( const OTYPE< IMPID > & group )

This function template returns the class of a group which is stored in its NX_class attribute.

Exceptions

invalid_object_error	if parent group is not valid
shape_mismatch_error	the attribute is not a scalar
type_error	the attribute type is not supported
io_error	attribute data retrieval failed
object_error	in case of any other error

Template Parameters

IMPID implementation ID for the group

Parameters

group the group for which the class should be obtained

Returns: string with class type

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

pni::core::string pni::io::nx::get_class ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Return the class of a group.

Exceptions

type_error	if the passed object is not a group
invalid_object_error	if the passed object is not valid
shape_mismatch_error	if NX_class attribute is not a scalar
io_error	if attribute data could not be retrieved
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	group as instance of nxobject

Returns: Nexus class as a tring

template<template< nximp_code > class OTYPE, nximp_code IMPID>

pni::core::string pni::io::nx::get_filename ( const OTYPE< IMPID > & o )

Return the filename an object belongs to. This template works for instances of

nxgroup
nxfield
nxattribute
links

Exceptions

invalid_object_error	in case of an invalid object
io_error	if filename cannot be retrieved
type_error	if the implementation type does not support filename retrieval
object_error	in case of any other error

Template Parameters

OTYPE	object type template
IMPID	implementation ID

Parameters

o	reference to the object

Returns: name of the object

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

pni::core::string pni::io::nx::get_filename ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Get the name of the file where a particular object is stored.

Exceptions

invalid_oject_error	if the object is not valid
io_error	if filename retrieval fails
type_error	if the implementation type does not support filename retrieval
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject

Returns: name of the object

template<template< nximp_code > class OTYPE, nximp_code IMPID>

pni::core::string pni::io::nx::get_name ( const OTYPE< IMPID > & o )

Return the name of an object. This template function is called in case that the object is an instance of

nxgroup
nxfile
nxattribute
nxlink

Exceptions

io_error	in case of problems
invalid_object_erro	in case of an invalid object
type_error	if a type cannot be retrieved for this type
object_error	in case of any other error

Template Parameters

OTYPE	object type template
IMPID	implementation ID

Parameters

o	reference to the object

Returns: name of the object

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

pni::core::string pni::io::nx::get_name ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Retriev the name of an object stored in an instance of the nxobject template.

Exceptions

io_error	in case of IO errors
invalid_oject_error	if the object is not valid
type_error	if a type cannot be retrieved for this type
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject

Returns: name of the object

template<typename OTYPE , typename PATHT >

auto pni::io::nx::get_object	(	const OTYPE &	o,
		const PATHT &	path
	)		-> decltype(get_parent(o))

Retrieve an object whose position is determined by a nexus path. The path can be either relative or absolute. In the former case the path is relative to the parent object. In the latter on the parent object is only used to retrieve the root group and then continue from there.

Exceptions

invalid_object_error	if the parent is not valid
type_error	if the object is not a group
key_error	if one of the path element does not lead to a child
object_error	in the case of any other error

Template Parameters

OTYPE	parent object type
IMPID	implementation ID of the parent tyep

Parameters

o	reference to the parent
path	reference to the path

Returns: the requested object as nxobject instance

template<typename OTYPE >

OTYPE pni::io::nx::get_object_by_class	(	const OTYPE &	parent,
		pni::core::string	c
	)

template<typename OTYPE >

OTYPE pni::io::nx::get_object_by_name	(	const OTYPE &	parent,
		const pni::core::string &	name
	)

Search for an object stored below its parent by name. The parent must be an instance of nxgroup or nxobject wrapping a group instance. IF the object could not be found a key_error exception is thrown.

Exceptions

key_error	if no object with the requested name exists
invalid_object_error	if the parent is not a valid object
io_error	in case of errors during object meta data retrieval
object_error	in case of any object construction or destruction problem

Parameters

parent	the parent object
name	the name of the requested object

Returns: the requested object as an instance of nxobject

template<typename OTYPE >

OTYPE pni::io::nx::get_object_by_name_and_class	(	const OTYPE &	parent,
		const pni::core::string &	name,
		const pni::core::string &	c
	)

This function searches for an object by its name and class. Obviously such an object can only be a group as fields do not have a class attribute.

The function first tries to find an object with a matching name. If it finds such an object it checks if it is a group and throws a type_error exception if it is not. In the case of a group the function continues to check if the group type matches.

Exceptions

invalid_object_error	if the parent object is not valid
io_error	in case of errors during retrieving object metadata
type_error	if the object found by name is not a group
key_error	if no object of the requested name and class could be found
object_error	in any case of errors during object creation, destruction, or copying

Template Parameters

OTYPE object type

Parameters

parent	the parent object
name	the name of the requested group
c	the class of the requested group

Returns: a group object of matching name and class

template<template< nximp_code > class OTYPE, nximp_code IMPID>

nxobject_trait<IMPID>::object_type pni::io::nx::get_parent ( const OTYPE< IMPID > & o )

Returns the parent object of an instance of nxfield, nxattribute, or nxgroup object. The parent is returned as an instance of nxobject.

Exceptions

invalid_object_error	if the child is not valid
type_error	if there are some issues with the internal type
object_error	in case of errors generating parent object

Template Parameters

OTYPE	object template
IMPID	implementation ID

Parameters

o	object instance

Returns: parent as nxobject instance

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

nxobject<GTYPE,FTYPE,ATYPE,LTYPE> pni::io::nx::get_parent ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Return the parent object of an instance of nxobject as a new instance of nxobject.

Exceptions

invalid_object_error	if the object is not valid
type_error	in case of internal type issues
object_error	in case of errors generating parent object

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject

Returns: parent object as instance of nxobject

template<template< nximp_code > class OTYPE, nximp_code IMPID>

pni::core::string pni::io::nx::get_path ( const OTYPE< IMPID > & o )

Return the path of an object as a string. The object can be either an instance of nxfield, nxgroup, or nxattribute.

Exceptions

invalid_object_error	if one of the fields parents could not be retrieved or the attribute itself is not valid
shape_mismatch_error	if a possible class attribute is not scalar
io_error	if class data retrieval failed
type_error	if the class attribute exists but is of the wrong type
object_error	in case of any other error

Template Parameters

OTYPE	object type template
IMPID	implementation ID

Parameters

o	object instance

Returns: path as string

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

pni::core::string pni::io::nx::get_path ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Return the path of an object stored in an nxobject instance.

Exceptions

invalid_object_error	if one of the fields parents could not be retrieved or the attribute itself is not valid
shape_mismatch_error	if a possible class attribute is not scalar
io_error	if class data retrieval failed
type_error	if the class attribute exists but is of the wrong type
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject

Returns: path as string

template<template< nximp_code > class OTYPE, nximp_code IMPID>

size_t pni::io::nx::get_rank ( const OTYPE< IMPID > & o )

Return the number of dimensions of an attribute or field.

Exceptions

invalid_object_error	if object is not valid
object_error	in case of any other error

Template Parameters

OTYPE	object template
IMPID	implementation ID of the object

Parameters

o	reference to the field or attribute

Returns: number of dimensions

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

size_t pni::io::nx::get_rank ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Return the number of dimensions of a field or attribute wrapped in an instance of nxobject.

auto field = get_object(root,path_to_field);

size_t r = get_rank(field);

Exceptions

invalid_object_error	if object is not valid
type_error	if the wrapped object is a group
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	object instance

Returns: number of dimensions

template<typename OTYPE >

auto pni::io::nx::get_root ( const OTYPE & p ) -> decltype(get_parent(p))

Return the root group of an object.

Exceptions

invalid_object_error	if the object is not valid
type_error	if the implementation does not support this operation
io_error	in the case that name retrieval fails
object_error	in case of any other error

Template Parameters

OTYPE object type

Parameters

p	reference an instance of OTYPE

Returns: an instance of nxobject with the root group

template<typename CTYPE , template< nximp_code > class OTYPE, nximp_code IMPID>

CTYPE pni::io::nx::get_shape ( const OTYPE< IMPID > & object )

Returns the shape of an attribute or field type. In the case of any other type compilation fails due to an internal static_assert statement. The container type used to retrieve the shape information must be provided by the user as a template parameter.

nxfield field = get_object(root,path_to_field);

auto shape = get_shape<shape_t>(field);

Exceptions

invalid_object_error	if the object is not valid
object_error	in case of any other error

Template Parameters

CTYPE	container type for the shape
OTYPE	object template
IMPID	implementation ID

Parameters

object the object for which the shape should be determined

Returns: instance of CTYPE with shape information

template<typename CTYPE , typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

CTYPE pni::io::nx::get_shape ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Returns the shape of an attribute or field type. In the case of any other type compilation fails due to an internal static_assert statement. The container type used to retrieve the shape information must be provided by the user as a template parameter.

object_types field = get_object(root,path_to_field);

auto shape = get_shape<shape_t>(field);

Exceptions

invalid_object_error	if the object is not valid
object_error	in case of any other error

Template Parameters

CTYPE	container type for the shape
GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of VTYPE

Returns: an instance of CTYPE with the elements for each dimension

template<template< nximp_code > class OTYPE, nximp_code IMPID>

size_t pni::io::nx::get_size ( const OTYPE< IMPID > & o )

Return the number of elements stored in a group, field, or attribute. In the case of a group this function template returns the number of children the group has. In the case of fields and attributes the number of elements are stored in the particular instance.

This template function works for

nxgroup
nxfield
nxattribute

Exceptions

invalid_object_error	if the object is not valid
object_error	in case of any other error

Template Parameters

OTYPE	object template
IPMID	implementation ID argument of the object template

Parameters

o	reference to the group, field, or attribute object

Returns: number of elements

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

size_t pni::io::nx::get_size ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Return the number of elements stored in a group, field, or attribute. In the case of a group this function template returns the number of children the group has. In the case of fields and attributes the number of elements are stored in the particular instance.

object_types field = get_object(root,path_to_field);

auto s = get_size(field);

Exceptions

invalid_object_error	if object is not valid
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject

Returns: size of the object

template<template< nximp_code > class OTYPE, nximp_code IMPID>

pni::core::type_id_t pni::io::nx::get_type ( const OTYPE< IMPID > & o )

Get the type ID of a field or attribute. If the type of the object is not an attribute or field type compilation will fails due to an static_insert within the template.

Exceptions

invalid_object_error	if the object is not valid
type_error	if the data type used is not suppported
object_error	in case of any other error

Template Parameters

OTYPE	object template
IMPID	implementation ID

Parameters

o	object reference

Returns: type ID

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

pni::core::type_id_t pni::io::nx::get_type ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

Get the type ID of a field or attribute.

object_types field = get_object(root,path_to_field);

type_id_t tc = get_type(field);

Exceptions

invalid_object_error	if the object is not valid
type_error	if the data type is not supported or the object is a group
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute_type
LTYPE	link type

Parameters

o	object wrapped into nxobject

Returns: value of type_id_t

template<typename FTYPE >

pni::core::string pni::io::nx::get_unit ( const FTYPE & field )

Return the unit string of a field. This function works only for field types as attributes cannot store unit information.

Template Parameters

invalid_object_error	if the field is not valid
shape_mismatch_error	if the unit attribute is not scalar
io_error	if reading the attribute failed
type_error	if the type used for the units attribute is not supported
object_error	in case of any other error

Parameters

field instance of the Nexus field

Returns: content of the units string

template<template< nximp_code > class OTYPE, nximp_code IMPID>

void pni::io::nx::grow	(	OTYPE< IMPID > &	o,
		size_t	dimension = `0`,
		size_t	extend = `1`
	)

Exceptions

invalid_object_error	if the field is not active
index_error	if dimension exceeds the rank
object_error	in case of any other error

Template Parameters

OTYPE	object template
IMPID	implementation ID of the object

Parameters

o	the object to grow
dimension	index of the dimension which to extend
extend	number of elements by which to extend

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

void pni::io::nx::grow	(	nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	o,
		size_t	d = `0`,
		size_t	e = `1`
	)

auto field = get_object(root,path_to_field);

grow(field,1,10);

Exceptions

invalid_object_error	if the field is not active
index_error	if dimension exceeds the rank
type_error	if the wrapped object is a group or attribute
object_error	in the case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject
d	dimension along which to grow
e	extent by which to grow along d

Returns: nothing

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

bool pni::io::nx::is_attribute ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

noexcept

Function template checking if the object stored in an nxobject instance is an instance of nxattribute. If this is the case true is returned, otherwise false. The function does not test for the validity of an object. It just provides runtime information about the type of the object stored in the nxobject instance.

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	reference to an instance of nxobject<GTYPE,FTYPE,ATYPE>

Returns: true if o is an attribute, false otherwise

template<template< nximp_code > class OTYPE, nximp_code IMPID>

bool pni::io::nx::is_class	(	const OTYPE< IMPID > &	object,
		const pni::core::string &	type
	)

This function template checks whether or not a group is of a particular type.

Exceptions

invalid_object_error	if parent group is not valid
shape_mismatch_error	the attribute is not a scalar
type_error	the attribute type is not supported
io_error	attribute data retrieval failed
object_error	in case of any other error

Template Parameters

OTYPE	nexus object template
IMPID	implementation ID of the object

Parameters

object	the group to check
type	the type we want ot check for

Returns: true if the group is of that type, false otherwise

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

bool pni::io::nx::is_class	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	o,
		const pni::core::string &	c
	)

Returns true if a group stored in an instance of nxobject is member of a particular class.

Exceptions

invalid_object_error	if parent group is not valid
shape_mismatch_error	the attribute is not a scalar
type_error	the attribute type is not supported
io_error	attribute data retrieval failed
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject
c	Nexus class to check for

Returns: true if group class and c match, false otherwise

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

bool pni::io::nx::is_field ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

noexcept

Function template testing if the object stored in an instance of nxobject is an instance of nxfield. If this is the case true is returned, false otherwise. The function does not test for validity of an object. It just helps to retrieve type information at runtime.

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of nxobject<GTYPE,FTYPE,ATYPE,LTYPE>

Returns: true if the object is a field, false otherwise

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

bool pni::io::nx::is_group ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

noexcept

Template function testing if the object stored in an instance of nxobject is an instance of nxgroup. If this is the case true is returned, false otherwise. The function does not test for the validity of the stored object. It just provides type information about the stored object at runtime.

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	reference to nxobject<GTYPE,FTYPE,ATYPE,LTYPE>

Returns: true if object is a group, false otherwise

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

bool pni::io::nx::is_link ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

noexcept

Template function testing if the object stored in an instance of nxobject is an instance of nxlink. If this is the case true is returned, false otherwise. The function does not test for the validity of the stored object. It just provides type information about the stored object at runtime.

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	reference to nxobject<GTYPE,FTYPE,ATYPE,LTYPE>

Returns: true if object is a group, false otherwise

template<typename OTYPE >

bool pni::io::nx::is_valid ( const OTYPE & o )

noexcept

Check if the passed object is valid and return true if this is the case. This template code takes instances

nxattribute
nxfield
nxgroup
nxfile
nxlink

as input arguments.

Exceptions

object_error if the validity check fails

Template Parameters

OTYPE object type

Parameters

o	instance of OTYPE

Returns: true if the object is valid

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

bool pni::io::nx::is_valid ( const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > & o )

noexcept

Test the validity of an object stored in an nxobject instance by calling the is_valid method on the particular instance.

auto o = ....;
if(!is_valid(o))
{
    std::cerr<<"Nexus object is not valid - abort program!"<<std::endl;
    return -1;
}

Exceptions

object_error if validity check fails

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	reference to nxobject<GTYPE,FTYPE,ATYPE,LTYPE>

Returns: true if valid, false otherwise

template<template< nximp_code > class OTYPE, nximp_code IMPID, typename ATYPE >

void pni::io::nx::read	(	const OTYPE< IMPID > &	o,
		ATYPE &	a
	)

Read data form an attribute or field type instance. This function tempalte reads the entire content of the field or attribute. The exceptions which are thrown here depend on ATYPE.

Exceptions

invalid_object_error	if the field is not valid
io_error	if reading the data fails
type_error	if the data type of ATYPE is not supported
memory_not_allocated_error	if ATYPE is an array type and its internal buffer has no memory associated with it
size_mismatch_error	if the number of elements of ATYPE and the field do not match
object_error	in case of any other error

Template Parameters

OTYPE	object template
IMPID	implementation ID for the object
ATYPE	array type where to store the data

Parameters

o	field or attribute instance
a	container instance

template<template< nximp_code > class OTYPE, nximp_code IMPID, typename ATYPE , typename... ITYPES>

void pni::io::nx::read	(	const OTYPE< IMPID > &	o,
		ATYPE &	a,
		ITYPES...	indices
	)

Read data form an attribute or field type instance. This function allows reading only a part of the field by passing a multiindex selection to the function. The exceptions which are thrown here depend on ATYPE.

Exceptions

shape_mismatch_error	if selection and field rank do not match
invalid_object_error	if the field is not valid
io_error	if reading the data fails
type_error	if the data type of ATYPE is not supported
memory_not_allocated_error	if ATYPE is an array type and its internal buffer has no memory associated with it
size_mismatch_error	if the number of elements of ATYPE and the field do not match
object_error	in case of any other error

Template Parameters

OTYPE	object template
IMPID	implementation ID for the object
ATYPE	array type where to store the data
ITYPES	index types

Parameters

o	field or attribute instance
a	container instance
indices	selection indices passed as variadic arguments

template<typename ATYPE , typename GTYPE , typename FTYPE , typename ATTYPE , typename LTYPE , typename... ITYPES>

void pni::io::nx::read	(	const nxobject< GTYPE, FTYPE, ATTYPE, LTYPE > &	o,
		ATYPE &	a,
		ITYPES...	indices
	)

This function template is a wrapper for the read_visitor. It will read data from the field or attribute stored in the variant type. Partial IO is supported only for fields. As data cannot be read from a group an exception will be thrown if the object stored in the variant type is a group object.

Exceptions

shape_mismatch_error	if selection and field rank do not match
invalid_object_error	if the field is not valid
io_error	if reading the data fails
type_error	if the data type of ATYPE is not supported
memory_not_allocated_error	if ATYPE is an array type and its internal buffer has no memory associated with it
size_mismatch_error	if the number of elements of ATYPE and the field do not match
object_error	in case of any other error

Template Parameters

ATYPE	target type for the read
GTYPE	group type
FTYPE	field type
ATTYPE	attribute type
LTYPE	link type
ITPYES	index types

Parameters

o	instance of VTYPE
a	instance of ATYPE with the data
indices	index type instances

Returns: nothing

template<typename ATYPE , typename GTYPE , typename FTYPE , typename ATTYPE , typename LTYPE >

void pni::io::nx::read	(	const nxobject< GTYPE, FTYPE, ATTYPE, LTYPE > &	o,
		ATYPE &	a,
		const std::vector< pni::core::slice > &	sel
	)

This function template is a wrapper for the read_visitor. It will read data from the field or attribute stored in the variant type. Partial IO is supported only for fields. As data cannot be read from a group an exception will be thrown if the object stored in the variant

Exceptions

shape_mismatch_error	if selection and field rank do not match
invalid_object_error	if the field is not valid
io_error	if reading the data fails
type_error	if the data type of ATYPE is not supported or the object passed by the user holds a group instance
memory_not_allocated_error	if ATYPE is an array type and its internal buffer has no memory associated with it
size_mismatch_error	if the number of elements of ATYPE and the field do not match
object_error	in case of any other error

Template Parameters

ATYPE	target type for the read
GTYPE	group type
FTYPE	field type
ATTYPE	attribute type
LTYPE	link type
ITPYES	index types

Parameters

o	instance of VTYPE
a	instance of ATYPE with the data
sel	selection from which to read

Returns: nothing

template<template< nximp_code > class OTYPE, nximp_code IMPID>

void pni::io::nx::set_class	(	const OTYPE< IMPID > &	o,
		const pni::core::string &	nxclass
	)

Sets the NX_class attribute at a group to a particular value.

Exceptions

type_error	if o is not a group
invalid_object_error	if the group is not valid
type_error	if the data type is not supported
object_error	in case of any other error

Template Parameters

OTYPE	object template
IMPID	implementation ID of the object

Parameters

o	group instance for which to set NX_class
nxclass	the value of NX_class

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

void pni::io::nx::set_class	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	o,
		const pni::core::string &	c
	)

Set the NX_class attribute for a group stored in an instance of nxobject.

Exceptions

type_error	if o is not a group
invalid_object_error	if the group is not valid
type_error	if the data type is not supported
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	group as instance of nxobject
c	Nexus class as string

template<typename FTYPE >

void pni::io::nx::set_unit	(	const FTYPE &	field,
		const pni::core::string &	value
	)

Set the unit for a field. The unit is stored in an attribute with name "units" of data type string. The attribute is scalar.

Exceptions

invalid_object_error	if field is not valid
type_error	if data type is not supported
io_error	if writing of the value fails
object_error	in case of any other error

Template Parameters

FTYPE field type

Parameters

field	instance of the field
value	the value for the units attribute

template<typename GTYPE , typename FTYPE , typename ATYPE , typename LTYPE >

void pni::io::nx::set_unit	(	const nxobject< GTYPE, FTYPE, ATYPE, LTYPE > &	o,
		const pni::core::string &	s
	)

Set the unit for a field. The unit is stored in an attribute with name "units" of data type string. The attribute is scalar.

Exceptions

invalid_object_error	if field is not valid
type_error	if data type is not supported
io_error	if writing of the value fails
object_error	in case of any other error

Template Parameters

GTYPE	group type
FTYPE	field type
ATYPE	attribute type
LTYPE	link type

Parameters

o	instance of the parent object
s	content of the unit string

template<template< nximp_code > class OTYPE, nximp_code IMPID, typename ATYPE >

void pni::io::nx::write	(	const OTYPE< IMPID > &	o,
		const ATYPE &	a
	)

This function writes the entire data from a field.

Exceptions

invalid_object_error	if the field is not valid
io_error	if writing the data fails
type_error	if the data type of ATYPE is not supported
memory_not_allocated_error	if ATYPE is an array type and its internal buffer has no memory associated with it
size_mismatch_error	if the number of elements of ATYPE and the field do not match
object_error	in case of any other error

Template Parameters

OTYPE	object template
IMPID	implementation ID of the object
ATYPE	storage type where the data is stored

Parameters

o	object instance to which to write the data
a	instance from which to write the data

template<template< nximp_code > class OTYPE, nximp_code IMPID, typename ATYPE , typename... ITYPES>

void pni::io::nx::write	(	const OTYPE< IMPID > &	o,
		const ATYPE &	a,
		ITYPES...	indices
	)

This function writes the entire data from a field.

Exceptions

shape_mismatch_error	if selection and field rank do not match
invalid_object_error	if the field is not valid
io_error	if reading the data fails
type_error	if the data type of ATYPE is not supported
memory_not_allocated_error	if ATYPE is an array type and its internal buffer has no memory associated with it
size_mismatch_error	if the number of elements of ATYPE and the field do not match
object_error	in case of any other error

Template Parameters

OTYPE	object template
IMPID	implementation ID of the object
ATYPE	storage type where the data is stored
ITYPES	index types

Parameters

o	object instance to which to write the data
a	instance from which to write the data
indices	selection indices passed as variadic arguments

template<typename ATYPE , typename GTYPE , typename FTYPE , typename AATYPE , typename LTYPE , typename... ITYPES>

void pni::io::nx::write	(	nxobject< GTYPE, FTYPE, AATYPE, LTYPE > &&	o,
		const ATYPE &	a,
		ITYPES...	indices
	)

This function template is a wrapper for the write_visitor. It will write data to the field or attribute stored in the variant type. Partial IO is supported only for fields. As data cannot be written to a group an exception will be thrown if the object stored in the variant type is a group object.

Exceptions

shape_mismatch_error	if selection and field rank do not match
invalid_object_error	if the field is not valid
io_error	if writing the data fails
type_error	if the data type of ATYPE is not supported
memory_not_allocated_error	if ATYPE is an array type and its internal buffer has no memory associated with it
size_mismatch_error	if the number of elements of ATYPE and the field do not match
object_error	in case of any other error

Template Parameters

ATYPE	data holding type
VTYPE	variant type
ITPYES	index types

Parameters

o	instance of VTYPE
a	instance of ATYPE with the data
indices	index type instances

Modules

Functions

Detailed Description

Function Documentation