Namespace alias for Boost.Hana, used for compile-time sequences and heterogeneous containers. More...

Namespaces
namespace	multiarray

Classes
struct	ConstReferenceMF
	Metafunction yielding the const-reference type of `State`. Defaults to `const State&`. Specialized for view types to return a const view. More...

struct	ConstReferenceMF< MultiArrayView< T, RANK > >

class	MultiArray
	Owning, move-only, rank-`RANK` array. Non-copyable; follows value semantics regarding constness. More...

class	MultiArrayView
	A non-owning, strided view over a contiguous buffer. Should be passed by value. More...

struct	ReferenceMF
	Metafunction yielding the reference type of `State`. Defaults to `State&`. Specialized for view types to return the view itself, since views are already reference-like. More...

struct	ReferenceMF< MultiArrayView< T, RANK > >

Concepts
concept	scalar
	Concept satisfied by scalar numeric types usable as operator coefficients: any type convertible to `double` or `dcomp`.

Typedefs
template<size_t RANK>
using	Extents = std::array< size_t, RANK >
	Compile-time–fixed shape and stride descriptor for a rank-`RANK` array. Should be passed by value, but can be `std::move`d in class constructors.

template<typename T , size_t RANK>
using	MultiArrayConstView = MultiArrayView< const T, RANK >
	Convenience alias: a view over immutable elements.

using	LogTree = json::object
	Namespace alias for Boost.JSON, used for structured logging and JSON serialization.

template<typename State >
using	Reference = typename ReferenceMF< State >::type
	Convenience alias for `ReferenceMF<State>::type`.

template<typename State >
using	ConstReference = typename ConstReferenceMF< State >::type
	Convenience alias for `ConstReferenceMF<State>::type`.

Functions
template<typename Type , std::size_t... sizes>
constexpr auto	concatenate (const std::array< Type, sizes > &... arrays)
	Concatenates multiple `std::array` instances of different sizes into one.

template<size_t RANK>
auto &	incrementMultiIndex (Extents< RANK > &idx, Extents< RANK > extents)
	Increments a multi-index in last-index-fastest order, in-place.

auto &	incrementMultiIndex (Extents< 0 > &idx, Extents< 0 >)
	Rank-0 no-op overload of `incrementMultiIndex` to satisfy template instantiation for degenerate cases.

template<typename T1 , typename T2 , size_t RANK>
void	checkExtents (MultiArrayConstView< T1, RANK > m1, MultiArrayConstView< T2, RANK > m2, std::string message)
	Debug-mode extent check between two views. Throws `std::runtime_error` on mismatch.

template<typename T1 , typename T2 , size_t RANK>
bool	isEqual (MultiArrayConstView< T1, RANK > m1, MultiArrayConstView< T2, RANK > m2)
	Element-by-element equality test. Traverses all elements via `incrementMultiIndex`.

template<typename T , size_t RANK>
void	checkContiguous (MultiArrayView< T, RANK > mav, std::string message)
	Debug-mode check that a view covers its storage as an owning `MultiArray` of the same extents would: offset 0 and first-index-fastest strides. Throws `std::invalid_argument` otherwise. For functions that address the flat storage directly; a sub-block or slice view fails it.

template<size_t RANK>
auto	vectorize (MultiArray< dcomp, RANK > &ma)
	Maps a mutable `MultiArray<dcomp,RANK>` to an Eigen column vector (no data copy).

template<size_t RANK>
auto	vectorize (const MultiArray< dcomp, RANK > &ma)
	Maps a const `MultiArray<dcomp,RANK>` to a const Eigen column vector (no data copy).

template<size_t TWO_TIMES_RANK> requires ( !(TWO_TIMES_RANK%2) )
Extents< TWO_TIMES_RANK/2 >	halveExtents (Extents< TWO_TIMES_RANK > extents)
	Extracts the first half of a rank-`2R` extent array, verifying that both halves are equal.

template<size_t TWO_TIMES_RANK>
auto	matricize (MultiArray< dcomp, TWO_TIMES_RANK > &ma)
	Maps a mutable rank-`2R` `MultiArray<dcomp>` to an Eigen square matrix (no data copy). The matrix dimension is `prod(extents[0..R-1])`; requires equal first and second half extents.

template<size_t TWO_TIMES_RANK>
auto	matricize (const MultiArray< dcomp, TWO_TIMES_RANK > &ma)
	Maps a const rank-`2R` `MultiArray<dcomp>` to a const Eigen square matrix (no data copy).

template<size_t RANK1, size_t RANK2>
auto	directProduct (const MultiArray< dcomp, RANK1 > &m1, const MultiArray< dcomp, RANK2 > &m2, std::function< dcomp(dcomp, dcomp)> func=std::multiplies< dcomp >{})
	Tensor (outer) product of two complex multi-arrays.

template<size_t RANK>
MultiArray< dcomp, RANK > &	conj (MultiArray< dcomp, RANK > &ma)
	In-place complex conjugation of all elements of `ma`.

template<size_t RANK>
double	frobeniusNormSqr (const MultiArray< dcomp, RANK > &ma)
	Squared Frobenius norm: \(\sum_{i}\|a_i\|^2\). Returns 0 for an empty array.

template<size_t RANK>
double	frobeniusNorm (const MultiArray< dcomp, RANK > &ma)
	Frobenius norm: \(\sqrt{\sum_{i}\|a_i\|^2}\).

template<size_t TWO_TIMES_RANK>
void	hermitianConjugateSelf (MultiArrayView< dcomp, TWO_TIMES_RANK > mav)
	In-place Hermitian conjugation of a rank-`2R` matrix view `mav`.

template<size_t TWO_TIMES_RANK>
void	twoTimesRealPartOfSelf (MultiArrayView< dcomp, TWO_TIMES_RANK > mav)
	In-place replacement of a rank-`2R` matrix view `mav` with `M + M†` (twice its Hermitian part).

std::string	toStringJSON (auto &&v)
	Serializes any JSON-convertible value to a string via `json::value_from`.

Variables
template<typename T , size_t RANK>
constexpr auto	passByValue_v< MultiArrayView< T, RANK > > = true
	`MultiArrayView` is cheap to copy and should always be passed by value.

template<typename T , size_t RANK>
constexpr auto	passByValue_v< MultiArray< T, RANK > > = false
	`MultiArray` owns its data and must not be passed by value.

template<typename T >
constexpr auto	passByValue_v =std::nullopt
	Primary template for the pass-by-value trait. Specializations are `true` for view types (e.g. `MultiArrayView`) and `false` for owning types (e.g. `MultiArray`). The primary template returns `std::nullopt` to signal the absence of a specialization.

Detailed Description

Namespace alias for Boost.Hana, used for compile-time sequences and heterogeneous containers.

Typedef Documentation

◆ ConstReference

template<typename State >

using cppqedutils::ConstReference = typedef typename ConstReferenceMF<State>::type

Convenience alias for ConstReferenceMF<State>::type.

◆ Extents

template<size_t RANK>

using cppqedutils::Extents = typedef std::array<size_t,RANK>

Compile-time–fixed shape and stride descriptor for a rank-RANK array. Should be passed by value, but can be std::moved in class constructors.

◆ LogTree

using cppqedutils::LogTree = typedef json::object

Namespace alias for Boost.JSON, used for structured logging and JSON serialization.

Alias for a JSON object used as a structured log tree. Passed through the trajectory and structure layers to accumulate human-readable, machine-parseable log data.

◆ MultiArrayConstView

template<typename T , size_t RANK>

using cppqedutils::MultiArrayConstView = typedef MultiArrayView<const T, RANK>

Convenience alias: a view over immutable elements.

◆ Reference

template<typename State >

using cppqedutils::Reference = typedef typename ReferenceMF<State>::type

Convenience alias for ReferenceMF<State>::type.

Function Documentation

◆ checkContiguous()

template<typename T , size_t RANK>

void cppqedutils::checkContiguous	(	MultiArrayView< T, RANK >	mav,
		std::string	message
	)

Debug-mode check that a view covers its storage as an owning MultiArray of the same extents would: offset 0 and first-index-fastest strides. Throws std::invalid_argument otherwise. For functions that address the flat storage directly; a sub-block or slice view fails it.

◆ checkExtents()

template<typename T1 , typename T2 , size_t RANK>

void cppqedutils::checkExtents	(	MultiArrayConstView< T1, RANK >	m1,
		MultiArrayConstView< T2, RANK >	m2,
		std::string	message
	)

Debug-mode extent check between two views. Throws std::runtime_error on mismatch.

◆ concatenate()

template<typename Type , std::size_t... sizes>

constexpr auto cppqedutils::concatenate ( const std::array< Type, sizes > &... arrays )

constexpr

Concatenates multiple std::array instances of different sizes into one.

Overcomes the limitation that std::views::join cannot join std::array instances of different sizes, since the size is part of the type. Uses C++17 fold expressions.

Template Parameters

Type	The element type, common to all input arrays.
sizes	The sizes of the input arrays, deduced from the arguments.

Parameters

arrays The arrays to concatenate.

Returns: A new std::array<Type, (sizes+...)> containing all elements in order.

See also: http://stackoverflow.com/a/42774523/1171157

◆ conj()

template<size_t RANK>

MultiArray< dcomp, RANK > & cppqedutils::conj ( MultiArray< dcomp, RANK > & ma )

In-place complex conjugation of all elements of ma.

◆ directProduct()

template<size_t RANK1, size_t RANK2>

auto cppqedutils::directProduct	(	const MultiArray< dcomp, RANK1 > &	m1,
		const MultiArray< dcomp, RANK2 > &	m2,
		std::function< dcomp(dcomp, dcomp)>	func = `std::multiplies<dcomp>{}`
	)

Tensor (outer) product of two complex multi-arrays.

Returns a MultiArray<dcomp, RANK1+RANK2> with extents concatenate(m1.extents, m2.extents). Element (i,j) of the result is func(m1[i], m2[j]); defaults to pointwise multiplication. Storage layout: result[i + stride*j] where stride = m1.dataView.size().

◆ frobeniusNorm()

template<size_t RANK>

double cppqedutils::frobeniusNorm ( const MultiArray< dcomp, RANK > & ma )

Frobenius norm: \(\sqrt{\sum_{i}|a_i|^2}\).

◆ frobeniusNormSqr()

template<size_t RANK>

double cppqedutils::frobeniusNormSqr ( const MultiArray< dcomp, RANK > & ma )

Squared Frobenius norm: \(\sum_{i}|a_i|^2\). Returns 0 for an empty array.

◆ halveExtents()

template<size_t TWO_TIMES_RANK>
requires ( !(TWO_TIMES_RANK%2) )

Extents< TWO_TIMES_RANK/2 > cppqedutils::halveExtents ( Extents< TWO_TIMES_RANK > extents )

Extracts the first half of a rank-2R extent array, verifying that both halves are equal.

A MultiArray<dcomp, 2R> with equal first and second half extents represents a square matrix (or tensor product of square matrices) of total dimension prod(extents[0..R-1]). Throws std::invalid_argument in debug mode if the two halves differ.

◆ hermitianConjugateSelf()

template<size_t TWO_TIMES_RANK>

void cppqedutils::hermitianConjugateSelf ( MultiArrayView< dcomp, TWO_TIMES_RANK > mav )

In-place Hermitian conjugation of a rank-2R matrix view mav.

Conjugates the diagonal, and swaps (i,j) and (j,i) while conjugating both. Operates directly on flat storage, so mav must be full and contiguous (checked by checkContiguous in debug builds); pass an owning array as ma.mutableView().

◆ incrementMultiIndex() [1/2]

auto & cppqedutils::incrementMultiIndex	(	Extents< 0 > &	idx,
		Extents< 0 >
	)

inline

Rank-0 no-op overload of incrementMultiIndex to satisfy template instantiation for degenerate cases.

◆ incrementMultiIndex() [2/2]

template<size_t RANK>

auto & cppqedutils::incrementMultiIndex	(	Extents< RANK > &	idx,
		Extents< RANK >	extents
	)

Increments a multi-index in last-index-fastest order, in-place.

Note: The iteration order is the opposite of the memory order: storage is first-index-fastest (see multiarray::calculateStrides), so successive multi-indices are not adjacent in memory unless all axes but the last have extent 1.

The iteration pattern is: increment the last index; on overflow, reset it to zero and carry to the previous index. The loop termination guard is idx[0] != extents[0] — once the leading index overflows the array is exhausted. The final increment leaves idx in an out-of-bounds state, consistent with how unchecked iterators work.

Note: TODO: formulate as a std::ranges-compliant range; see SliceIterator.h for a draft.

◆ isEqual()

template<typename T1 , typename T2 , size_t RANK>

bool cppqedutils::isEqual	(	MultiArrayConstView< T1, RANK >	m1,
		MultiArrayConstView< T2, RANK >	m2
	)

Element-by-element equality test. Traverses all elements via incrementMultiIndex.

Note: Not spelled operator== — this can be an expensive operation.

◆ matricize() [1/2]

template<size_t TWO_TIMES_RANK>

auto cppqedutils::matricize ( const MultiArray< dcomp, TWO_TIMES_RANK > & ma )

Maps a const rank-2R MultiArray<dcomp> to a const Eigen square matrix (no data copy).

◆ matricize() [2/2]

template<size_t TWO_TIMES_RANK>

auto cppqedutils::matricize ( MultiArray< dcomp, TWO_TIMES_RANK > & ma )

Maps a mutable rank-2R MultiArray<dcomp> to an Eigen square matrix (no data copy). The matrix dimension is prod(extents[0..R-1]); requires equal first and second half extents.

◆ toStringJSON()

std::string cppqedutils::toStringJSON ( auto && v )

Serializes any JSON-convertible value to a string via json::value_from.

Parameters

v	Any value for which `boost::json::value_from` is defined.

Returns: A JSON string representation of v.

◆ twoTimesRealPartOfSelf()

template<size_t TWO_TIMES_RANK>

void cppqedutils::twoTimesRealPartOfSelf ( MultiArrayView< dcomp, TWO_TIMES_RANK > mav )

In-place replacement of a rank-2R matrix view mav with M + M† (twice its Hermitian part).

The diagonal becomes 2*re(mav(i,i)). For each pair i < j, mav(i,j) becomes mav(i,j) + conj(mav(j,i)), and mav(j,i) its conjugate. C++QED's master equation uses it to complete \((H_\text{eff}/i)\rho\) to \((H_\text{eff}/i)\rho + \rho\,(H_\text{eff}/i)^\dagger\), and to make \(\rho\) exactly Hermitian after each step. Operates directly on flat storage, so mav must be full and contiguous (checked by checkContiguous in debug builds).

◆ vectorize() [1/2]

template<size_t RANK>

auto cppqedutils::vectorize ( const MultiArray< dcomp, RANK > & ma )

Maps a const MultiArray<dcomp,RANK> to a const Eigen column vector (no data copy).

◆ vectorize() [2/2]

template<size_t RANK>

auto cppqedutils::vectorize ( MultiArray< dcomp, RANK > & ma )

Maps a mutable MultiArray<dcomp,RANK> to an Eigen column vector (no data copy).

Variable Documentation

◆ passByValue_v

template<typename T >

constexpr auto cppqedutils::passByValue_v =std::nullopt

constexpr

Primary template for the pass-by-value trait. Specializations are true for view types (e.g. MultiArrayView) and false for owning types (e.g. MultiArray). The primary template returns std::nullopt to signal the absence of a specialization.

◆ passByValue_v< MultiArray< T, RANK > >

template<typename T , size_t RANK>

constexpr auto cppqedutils::passByValue_v< MultiArray< T, RANK > > = false

constexpr

MultiArray owns its data and must not be passed by value.

◆ passByValue_v< MultiArrayView< T, RANK > >

template<typename T , size_t RANK>

constexpr auto cppqedutils::passByValue_v< MultiArrayView< T, RANK > > = true

constexpr

MultiArrayView is cheap to copy and should always be passed by value.

Namespaces

Classes

Concepts

Typedefs

Functions

Variables

Detailed Description

Typedef Documentation

◆ ConstReference

◆ Extents

◆ LogTree

◆ MultiArrayConstView

◆ Reference

Function Documentation

◆ checkContiguous()

◆ checkExtents()

◆ concatenate()

◆ conj()

◆ directProduct()

◆ frobeniusNorm()

◆ frobeniusNormSqr()

◆ halveExtents()

◆ hermitianConjugateSelf()

◆ incrementMultiIndex() [1/2]

◆ incrementMultiIndex() [2/2]

◆ isEqual()

◆ matricize() [1/2]

◆ matricize() [2/2]

◆ toStringJSON()

◆ twoTimesRealPartOfSelf()

◆ vectorize() [1/2]

◆ vectorize() [2/2]

Variable Documentation

◆ passByValue_v

◆ passByValue_v< MultiArray< T, RANK > >

◆ passByValue_v< MultiArrayView< T, RANK > >