lf::base Namespace Reference

Contains basic functionality that is used by other parts of LehrFEM++. More...

Classes
class	AutoTimer
	Measures execution time between construction and destruction. AutoTimer can output either to a std::ostream or to a spdlog::logger More...
class	InvalidTypeException
	Thrown to signal that an argument passed to a function had the wrong (polymorphic) type. More...
struct	IsScalar
	Base Traits class which can be used to determine if a type T is a scalar value. More...
struct	IsScalar< std::complex< T >, std::enable_if_t< std::is_arithmetic_v< T > > >
	Also std::complex is a "scalar" type if the underlying type is a std::is_arithmetic type. More...
struct	IsScalar< T, std::enable_if_t< std::is_arithmetic_v< T > > >
	any type that is a std::is_arithmetic is also a scalar type. More...
class	LehrFemInfo
	Provides extra information about this version of LehrFEM++, in particular licensing information. More...
class	LfException
	A simple, general purpose exception class that is thrown by LehrFEM++ if something is wrong. More...
class	LineFeedFormatter
	A spdlog formatter which wraps another formatter and makes sure that if there are new lines (\n) in the log message, that the log message is still properly indented. More...
class	PredicateTrue
	A Function Object that can be invoked with any arguments and that always returns the value true. More...
class	RefEl
	Represents a reference element with all its properties. More...
class	Timer
	Timer class to measure time. More...

Concepts
concept	EigenMatrix
	Check if a given type T is an Eigen::Matrix.
concept	EigenArray
	Check if a given type T is a Eigen::Array<...>&
concept	Scalar
	Concept which is fulfilled if a type T is a scalar type, i.e. if it is a "field" in the mathematical sense.

Typedefs
using	size_type = unsigned int
	general type for variables related to size of arrays
using	glb_idx_t = unsigned int
	type for global index of mesh entities (nodes, edges, cells)
using	sub_idx_t = unsigned int
	type for local indices of sub-entities
using	dim_t = unsigned int
	type for dimensions and co-dimensions and numbers derived from them

Enumerations
enum class	RefElType : unsigned char { kPoint = 1 , kSegment = 2 , kTria = 3 , kQuad = 4 }
	An enum that defines all possible RefEl types. More...

Functions
void	AssertionFailed (const std::string &expr, const std::string &file, long line, const std::string &msg)
template<class TO, class FROM>
auto	narrow (FROM from) noexcept -> TO
	cast from to TO using static_cast. An assert will fail if this would change the value (e.g. because of overflow when an std::int64_t is converted to a std::int32_t)
void	PrintInfo (std::ostream &stream, const RefEl &ref_el, int output_ctrl)
std::ostream &	operator<< (std::ostream &stream, const RefEl &ref_el)
	Operator overload to print a RefEl to a stream, such as std::cout
std::shared_ptr< spdlog::logger >	InitLogger (const std::string &name)
	Create a spdlog logger, register it in the spdlog registry and initialize it with LehrFEM++ specific settings.
void	PrintInfo (std::ostream &stream, const RefEl &ref_el, int output_ctrl=0)
	Diagnostic output operator. Prints info about a reference element.

Variables
const unsigned int	kIdxNil = static_cast<unsigned int>(-1)
	Index flagged as invalid.
constexpr double	kPi = 3.14159265358979323846

Detailed Description

Contains basic functionality that is used by other parts of LehrFEM++.

Enumeration Type Documentation

RefElType

enum class lf::base::RefElType : unsigned char

strong

An enum that defines all possible RefEl types.

This enum is only rarely used direcly because there is a one-to-one relation between every enum value and an instance of the lf::base::RefEl class:

  RefElType::kPoint == RefEl::kPoint();
  RefElType::kSegment == RefEl::kSegment();
  RefElType::kTria == RefEl::kTria();
  RefElType::kQuad == RefEl::kQuad();

Also the enum representation is convertible into a lf::base::RefEl instance and back:

  RefElType point = RefEl::kPoint();
  auto segment = RefEl(RefElType::kSegment);

Enumerator
kPoint	Returns the (0-dimensional) reference point.
kSegment	Returns the (1-dimensional) reference segment. Node numbering with (1D) node coordinates
kTria	Returns the reference triangle. Node numbering with (2D) node coordinates and segment orientation.
kQuad	Returns the reference quadrilateral. Node numbering with (2D) node coordinates and segment orientation

Definition at line 31 of file ref_el.h.

Function Documentation

AssertionFailed()

void lf::base::AssertionFailed	(	const std::string &	expr,
		const std::string &	file,
		long	line,
		const std::string &	msg )

Definition at line 12 of file lf_assert.cc.

InitLogger()

std::shared_ptr< spdlog::logger > lf::base::InitLogger

(

const std::string &

name

)

Create a spdlog logger, register it in the spdlog registry and initialize it with LehrFEM++ specific settings.

Parameters

name	The name of the logger, is usually equal to the fully-scoped variable name, e.g. lf::mesh::hybrid2d::Mesh::Logger or lf::assemble::AssembleMatrixLogger

Returns

The initialized logger

LehrFEM++ uses spdlog loggers to provide the user with additional information about long running operations. These loggers are either associated with a class, in which case they are static, public member functions of this class (e.g. lf::mesh::hybrid2d::Mesh::Logger()) or they are associated with a free function in which case they are retrieved through a global free function lying in the same namespace as the free function (e.g. lf::assemble::AssembleMatrixLogger()).

You should use InitLogger() to initialize these loggers. In this way, we can set some sensible defaults for all LehrFEM++ loggers at one central location.

Note

So far a call to this method is essentially forwarded to spdlog::stdout_color_mt() and the formatter is set to a LineFeedFormatter.

auto logger = lf::base::InitLogger("logger_name");
logger->info("Hello, World!");

This will output:

[2024-10-07 18:07:21.081] [logger_name] [info] Hello, World!

Definition at line 16 of file spdlog_utils.cc.

Referenced by lf::assemble::AssembleMatrixLogger(), lf::fe::DiffusionElementMatrixProviderLogger(), lf::uscalfe::LinearFeLocalLoadVectorLogger(), lf::mesh::hybrid2d::Mesh::Logger(), lf::mesh::hybrid2d::MeshFactory::Logger(), lf::mesh::utils::TorusMeshBuilder::Logger(), lf::mesh::utils::TPQuadMeshBuilder::Logger(), lf::mesh::utils::TPTriagMeshBuilder::Logger(), lf::refinement::MeshHierarchy::Logger(), lf::uscalfe::LinearFELaplaceElementMatrix::Logger(), lf::fe::MassEdgeMatrixProviderLogger(), lf::uscalfe::MassEdgeMatrixProviderLogger(), lf::fe::MassElementMatrixProviderLogger(), lf::uscalfe::ReactionDiffusionElementMatrixProviderLogger(), lf::fe::ScalarLoadEdgeVectorProviderLogger(), lf::uscalfe::ScalarLoadEdgeVectorProviderLogger(), lf::fe::ScalarLoadElementVectorProviderLogger(), lf::uscalfe::ScalarLoadElementVectorProviderLogger(), and lf::mesh::test_utils::WatertightLogger().

narrow()

template<class TO, class FROM>

auto lf::base::narrow ( FROM from ) -> TO

noexcept

cast from to TO using static_cast. An assert will fail if this would change the value (e.g. because of overflow when an std::int64_t is converted to a std::int32_t)

Template Parameters

TO	Type to which we want to convert
FROM	Type from which we convert

Parameters

from	original value

Returns

static_cast<TO>(std::forward<FROM>(from))

Definition at line 31 of file narrow.h.

Referenced by lf::geometry::SegmentO1::ChildGeometry(), lf::geometry::TriaO1::ChildGeometry(), lf::refinement::Hybrid2DRefinementPattern::ChildPolygons(), lf::io::GmshReader::InitGmshFile(), lf::io::GmshReader::InitGmshFile(), lf::fe::MeshFunctionGradFE< SCALAR_FE, SCALAR_COEFF >::operator()(), lf::mesh::Mesh::PrintInfo(), and lf::io::writeTikZ().

operator<<()

std::ostream & lf::base::operator<< ( std::ostream & stream, const RefEl & ref_el )

inline

Operator overload to print a RefEl to a stream, such as std::cout

Parameters

stream	The stream to which this function should output
ref_el	The reference element to write to stream.

Returns

The stream itself.

Note

This function directly calls RefEl::ToString().

Usage example

  std::cout << RefEl::kSegment();  // prints "kSegment"

Definition at line 535 of file ref_el.h.

References lf::base::RefEl::ToString().

PrintInfo() [1/2]

void lf::base::PrintInfo ( std::ostream & stream, const RefEl & ref_el, int output_ctrl )

related

Definition at line 17 of file ref_el.cc.

Variable Documentation

kPi

double lf::base::kPi = 3.14159265358979323846

constexpr

Definition at line 39 of file types.h.

Referenced by lf::mesh::utils::TorusMeshBuilder::Build().