A volume data subfile written inside an H5 file. More...

#include <VolumeData.hpp>

Public Member Functions
	VolumeData (bool subfile_exists, detail::OpenGroup &&group, hid_t location, const std::string &name, uint32_t version=1)
	VolumeData (const VolumeData &)=delete
VolumeData &	operator= (const VolumeData &)=delete
	VolumeData (VolumeData &&)=delete
VolumeData &	operator= (VolumeData &&)=delete
const std::string &	get_header () const
uint32_t	get_version () const
void	write_volume_data (size_t observation_id, double observation_value, const std::vector< ElementVolumeData > &elements, const std::optional< std::vector< char > > &serialized_domain=std::nullopt, const std::optional< std::vector< char > > &serialized_observation_functions_of_time=std::nullopt, const std::optional< std::vector< char > > &serialized_global_functions_of_time=std::nullopt)
	Write volume data at an observation id and observation value.
bool	has_domain () const
bool	has_global_functions_of_time () const
template<size_t SpatialDim>
void	extend_connectivity_data (const std::vector< size_t > &observation_ids)
	Overwrites the current connectivity dataset with a new one. This new connectivity dataset builds connectivity within each block in the domain for each observation id in a list of observation id's.
void	write_tensor_component (const size_t observation_id, const std::string &component_name, const DataVector &contiguous_tensor_data, bool overwrite_existing=false)
void	write_tensor_component (const size_t observation_id, const std::string &component_name, const std::vector< float > &contiguous_tensor_data, bool overwrite_existing=false)
std::vector< size_t >	list_observation_ids () const
	List all the integral observation ids in the subfile.
double	get_observation_value (size_t observation_id) const
	Get the observation value at the the integral observation id in the subfile.
size_t	find_observation_id (double observation_value, const std::optional< double > &observation_value_epsilon=std::nullopt) const
	Find the observation ID that matches the observation_value
std::vector< std::string >	list_tensor_components (size_t observation_id) const
	List all the tensor components at observation id observation_id
std::vector< std::string >	get_grid_names (size_t observation_id) const
	List the names of all the grids at observation id observation_id
TensorComponent	get_tensor_component (size_t observation_id, const std::string &tensor_component) const
	Read a tensor component with name tensor_component at observation id observation_id from all grids in the file.
std::vector< std::vector< size_t > >	get_extents (size_t observation_id) const
	Read the extents of all the grids stored in the file at the observation id observation_id
auto	get_data_by_element (std::optional< double > start_observation_value, std::optional< double > end_observation_value, const std::optional< std::vector< std::string > > &components_to_retrieve=std::nullopt) const -> std::vector< std::tuple< size_t, double, std::vector< ElementVolumeData > > >
	Retrieve volume data for IDs in [start_observation_value, end_observation_value].
size_t	get_dimension () const
	Read the dimensionality of the grids. Note : This is the dimension of the grids as manifolds, not the dimension of the embedding space. For example, the volume data of a sphere is 2-dimensional, even though each point has an x, y, and z coordinate.
std::vector< std::vector< Spectral::Basis > >	get_bases (size_t observation_id) const
	Return the basis being used for each element along each axis.
std::vector< std::vector< Spectral::Quadrature > >	get_quadratures (size_t observation_id) const
	Return the quadrature being used for each element along each axis.
std::optional< std::vector< char > >	get_domain () const
	Get the serialized domain if it was written.
std::optional< std::vector< char > >	get_functions_of_time (size_t observation_id) const
	Get the observation-specific serialized functions of time at an `observation_id` if they were written.
std::optional< std::vector< char > >	get_global_functions_of_time () const
	Get the serialized global functions of time in the subfile if they were written.
const std::string &	subfile_path () const override
	Return the path to the subfile where this object is stored.

Static Public Member Functions
static std::string	extension ()
static char	separator ()
	Return the character used as a separator between grids in the subfile.

Detailed Description

A volume data subfile written inside an H5 file.

The volume data inside the subfile can be of any dimensionality greater than zero. This means that in a 3D simulation, data on 2-dimensional surfaces are written as a VolumeData subfile. Data can be written using the write_volume_data() method. An integral observation id is used to keep track of the observation instance at which the data is written, and associated with it is a floating point observation value, such as the simulation time at which the data was written. The observation id will generally be the result of hashing the temporal identifier used for the simulation.

Grid names: The data stored in the subfile are the tensor components passed to the write_volume_data() method as a std::vector<ElementVolumeData>. Typically the GRID_NAME should be the output of the stream operator of the spatial ID of the parallel component element sending the data to be observed. For example, in the case of a dG evolution where the spatial IDs are ElementIds, the grid names would be of the form [B0,(L2I3,L2I3,L2I3)].

Data layout in the H5 file: The data are written contiguously inside of the H5 subfile, in that each tensor component has a single dataset which holds all of the data from all elements, e.g. a tensor component T_xx which is found on all grids appears in the path H5_FILE_NAME/SUBFILE_NAME.vol/OBSERVATION_ID/GRID_NAME/T_xx and that is where all of the T_xx data from all of the grids resides. Note that coordinates must be written as tensors in order to visualize the data in ParaView, Visit, etc. In order to reconstruct which data came from which grid, the get_grid_names(), and get_extents() methods list the grids and their extents in the order which they and the data were written. For example, if the first grid has name GRID_NAME with extents {2, 2, 2}, it was responsible for contributing the first 2*2*2 = 8 grid points worth of data in each tensor dataset. Use the h5::offset_and_length_for_grid function to compute the offset into the contiguous dataset that corresponds to a particular grid.

Domain and FunctionsOfTime: A serialized representation of the domain and the functions of time can be written into the subfile alongside the tensor data. Reconstructing the domain (specifically the block maps) is needed for accurate interpolation of the tensor data to another set of points. The domain is currently stored as a std::vector<char>, and it is up to the calling code to serialize and deserialize the data, taking into account that files may be written and read with different versions of the code.

Warning: Currently the topology of the grids is assumed to be tensor products of lines, i.e. lines, quadrilaterals, and hexahedrons. However, this can be extended in the future. If support for more topologies is required, please file an issue.

Member Function Documentation

◆ find_observation_id()

size_t h5::VolumeData::find_observation_id	(	double	observation_value,
		const std::optional< double > &	observation_value_epsilon = std::nullopt ) const

Find the observation ID that matches the observation_value

Details

An epsilon can be specified and the observation id that matches within the epsilon of observation_value will be returned. If there is more than one id that is within the epsilon, an error will occur. If no epsilon is specified, this function will do exact comparison.

◆ get_data_by_element()

auto h5::VolumeData::get_data_by_element	(	std::optional< double >	start_observation_value,
		std::optional< double >	end_observation_value,
		const std::optional< std::vector< std::string > > &	components_to_retrieve = std::nullopt ) const -> std::vector< std::tuple< size_t, double, std::vector< ElementVolumeData > > >

Retrieve volume data for IDs in [start_observation_value, end_observation_value].

Returns a std::vector over times, sorted in ascending order of the observation value (the time in evolutions). The vector holds a std::tuple that holds

the integral observation ID
the observation value (time in evolutions)
a vector of ElementVolumeData sorted by the elements' name string.

If start_observation_value is std::nullopt then return everything from the beginning of the data to end_observation_value. If end_observation_value is std::nullopt then return everything from start_observation_value to the end of the data.
If components_to_retrieve is std::nullopt then return all components.

◆ get_header()

const std::string & h5::VolumeData::get_header ( ) const

inline

Returns: the header of the VolumeData file

◆ get_version()

uint32_t h5::VolumeData::get_version ( ) const

inline

Returns: the user-specified version number of the VolumeData file

Note: h5::Version returns a uint32_t, so we return one here too for the version

◆ has_domain()

bool h5::VolumeData::has_domain ( ) const

Returns: true if a serialized domain has been written to the subfile.

◆ has_global_functions_of_time()

bool h5::VolumeData::has_global_functions_of_time ( ) const

Returns: true if serialized functions of time have been written to the subfile.

◆ list_observation_ids()

std::vector< size_t > h5::VolumeData::list_observation_ids ( ) const

List all the integral observation ids in the subfile.

The list of observation IDs is sorted by their observation value, as returned by get_observation_value(size_t).

◆ subfile_path()

const std::string & h5::VolumeData::subfile_path ( ) const

inlineoverridevirtual

Return the path to the subfile where this object is stored.

Implements h5::Object.

◆ write_volume_data()

void h5::VolumeData::write_volume_data	(	size_t	observation_id,
		double	observation_value,
		const std::vector< ElementVolumeData > &	elements,
		const std::optional< std::vector< char > > &	serialized_domain = std::nullopt,
		const std::optional< std::vector< char > > &	serialized_observation_functions_of_time = std::nullopt,
		const std::optional< std::vector< char > > &	serialized_global_functions_of_time = std::nullopt )

Write volume data at an observation id and observation value.

Parameters

observation_id	The integral observation id at which the data is written.
observation_value	The floating point observation value (e.g. time) at which the data is written.
elements	The volume data to write, passed as a vector of ElementVolumeData structs.
serialized_domain	An optional serialized domain. It will only be written if there is not already a domain stored in the subfile.
serialized_observation_functions_of_time	An optional serialized observation-specific functions of time. It should be valid at the given observation value, but not contain the entire history to save space.
serialized_global_functions_of_time	An optional serialized global functions of time oject. It should be valid for the entire simulation. It will be used to overwrite the existing global functions of time iff the old object was written at a smaller observation_value (i.e. an earlier time).

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

src/IO/H5/VolumeData.hpp

Public Member Functions

Static Public Member Functions