svec::SVector Class Reference

A container for sparse vectors. More...

#include <svector.h>

Public Member Functions
	SVector ()=default
	Construct a new SVector object with no non-zero elements.
	SVector (const Element &elm)
	Construct a new SVector object with a single non-zero element.
	SVector (const Element *const buff)
	Construct a new SVector object with non-zero elements given in buff.
Value	sum () const
	Get the sum of values.
std::size_t	NNZ () const noexcept
	Get the number of non-zero elements.
bool	isEmpty () const noexcept
	Check if any non-zero elements.
Value	getMinValue () const
	Get the minimum non-zero entry.
Value	getMaxValue () const
	Get the maximum non-zero entry.
Label	getMaxLabel () const
	Get the maximum label.
const Element *	data () const noexcept
	Directly access the non-zero elements.
bool	containsNaN () const
	Check if any elements have a NaN value.
std::vector< Element >::const_iterator	begin () const noexcept
	Start of the non-zero elements.
std::vector< Element >::const_iterator	end () const noexcept
	End of the non-zero elements.
void	add (const SVector &a, const Value &C=1.0)
	Inplace Addition (and Multiplication), s=s+a*C.
void	add (const NormalizedSVector &a, const Value &C=1.0)
	Inplace Addition (and Multiplication), s=s+a*C.
void	normalize (const Value &total=1.0)
	s=s/sum(s) * total
void	chop (const Value &ref=0.0)
	Remove small elements in s.
void	zeroEntry (const Label &l)
	Set the entry at label l to zero.
void	clear () noexcept
	Clear out all non-zero entries.

Friends
SVector	fma (const SVector &a, const Value &C, const SVector &b)
	Fused Multiply and Add, C*a+b.
SVector	operator/ (const SVector &a, const Value &C)
	Division, a/C.
SVector	operator* (const SVector &a, const Value &C)
	Multiplication, a*C.

Detailed Description

A container for sparse vectors.

The SVector class is used to store a vector \(\mathbf{s}\) in terms of its non-zero elements \(s_\ell\). The underlying storage structure is a std::vector<Element>, which allows the storage to grow dynamically as the number of non-zero elements changes.

Note

While elements \(s_\ell\) are refereed to in documentation as ''non-zero elements'', it is not guaranteed that \(s_\ell\ne 0\) until chop() is called, after which it is guaranteed \(s_\ell\gt 0\).

Constructor & Destructor Documentation

SVector() [1/2]

svec::SVector::SVector ( const Element &  elm )

inline

Construct a new SVector object with a single non-zero element.

Parameters

elm	The non-zero element

SVector() [2/2]

svec::SVector::SVector

(

const Element *const

buff

)

Construct a new SVector object with non-zero elements given in buff.

Note

The elements in buff must be sorted in ascending order by label, with no repeated labels.

Parameters

buff	A sequence of elements, ending in END_ELEMENT

Member Function Documentation

add() [1/2]

void svec::SVector::add	(	const NormalizedSVector &	a,
		const Value &	C = 1.0
	)

Inplace Addition (and Multiplication), s=s+a*C.

For an NormalizedSVector \(\tilde{\mathbf{a}}\) and a Value \(C\), changes this \(\mathbf{s}\) by

\[ \mathbf{s} \gets \mathbf{s} + \left(C \times \tilde{\mathbf{a}}\right) \]

Parameters

a	NormalizedSVector, \(\tilde{\mathbf{a}}\)
C	Value, \(C\)

add() [2/2]

void svec::SVector::add	(	const SVector &	a,
		const Value &	C = 1.0
	)

Inplace Addition (and Multiplication), s=s+a*C.

For an SVector \(\mathbf{a}\) and a Value \(C\), changes this \(\mathbf{s}\) by

\[ \mathbf{s} \gets \mathbf{s} + \left(C \times \mathbf{a}\right) \]

Parameters

a	SVector, \(\mathbf{a}\)
C	Value, \(C\)

begin()

std::vector< Element >::const_iterator svec::SVector::begin ( ) const

inlinenoexcept

Start of the non-zero elements.

Returns the (constant) beginning iterator for the underlying std::vector<Element>

Returns

std::vector<Element>::const_iterator

chop()

void svec::SVector::chop

(

const Value &

ref = 0.0

)

Remove small elements in s.

For any \(s_l\le \varepsilon R \), \( s_l \gets 0 \). Where \( \varepsilon \) is machine precision.

Parameters

ref

\( R \)

clear()

void svec::SVector::clear ( )

inlinenoexcept

Clear out all non-zero entries.

This has the effect of \(\mathbf{s}\gets\mathbf{0}\).

Note

Does not change the allocated memory

containsNaN()

bool svec::SVector::containsNaN

(

)

const

Check if any elements have a NaN value.

Returns

true if any non-zero elements has a value of NaN

false otherwise

data()

const Element * svec::SVector::data ( ) const

inlinenoexcept

Directly access the non-zero elements.

Returns a direct pointer to the memory array used by the underlying std::vector<Element>

end()

std::vector< Element >::const_iterator svec::SVector::end ( ) const

inlinenoexcept

End of the non-zero elements.

Returns the (constant) end iterator for the underlying std::vector<Element>

Returns

std::vector<Element>::const_iterator

getMaxLabel()

Label svec::SVector::getMaxLabel

(

)

const

Get the maximum label.

Returns zero if NNZ()==0

Returns

Label

getMaxValue()

Value svec::SVector::getMaxValue

(

)

const

Get the maximum non-zero entry.

Returns

Value

getMinValue()

Value svec::SVector::getMinValue

(

)

const

Get the minimum non-zero entry.

Returns

Value

isEmpty()

bool svec::SVector::isEmpty ( ) const

inlinenoexcept

Check if any non-zero elements.

Returns

true if NNZ()==0

false if NNZ()!=0

NNZ()

std::size_t svec::SVector::NNZ ( ) const

inlinenoexcept

Get the number of non-zero elements.

Returns the number of non-zero elements in this \(\mathbf{s}\)

normalize()

void svec::SVector::normalize

(

const Value &

total = 1.0

)

s=s/sum(s) * total

If sum(s) is zero or sum(s)/total is subnormal, \(\mathbf{s}\gets\mathbf{0}\).

Parameters

total

sum()

Value svec::SVector::sum

(

)

const

Get the sum of values.

Returns

Value

zeroEntry()

void svec::SVector::zeroEntry

(

const Label &

l

)

Set the entry at label l to zero.

\[ s_l \gets 0 \]

Parameters

l	the label to set to zero

Friends And Related Symbol Documentation

fma

SVector fma ( const SVector &  a, const Value &  C, const SVector &  b  )

friend

Fused Multiply and Add, C*a+b.

For two SVector \(\mathbf{a}\) and \(\mathbf{b}\) and a Value \(C\), returns

\[ \left(C \times \mathbf{a}\right) + \mathbf{b} \]

Parameters

a	SVector, \(\mathbf{a}\)
C	Value, \(C\)
b	SVector, \(\mathbf{b}\)

Returns

SVector

operator*

SVector operator* ( const SVector &  a, const Value &  C  )

friend

Multiplication, a*C.

For a SVector \(\mathbf{a}\) and a Value \(C\), returns

\[ \mathbf{a} * C \]

Parameters

a	SVector, \(\mathbf{a}\)
C	Value, \(C\)

Returns

SVector

operator/

SVector operator/ ( const SVector &  a, const Value &  C  )

friend

Division, a/C.

For a SVector \(\mathbf{a}\) and a Value \(C\), returns

\[ \mathbf{a} / C \]

Parameters

a	SVector, \(\mathbf{a}\)
C	Value, \(C\)

Returns

SVector

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

• /home/runner/work/flexELA/flexELA/src/svector/svector.h