Representation of a vector as an array for real coefficients. More...

Data Structures
struct	_realavector

Typedefs
typedef struct _realavector	realavector

typedef realavector *	prealavector

typedef const realavector *	pcrealavector

Functions
prealavector	init_realavector (prealavector v, uint dim)
	Initialize an realavector object. More...

prealavector	init_sub_realavector (prealavector v, prealavector src, uint dim, uint off)
	Initialize an realavector object to represent a subvector. More...

prealavector	init_pointer_realavector (prealavector v, preal src, uint dim)
	Initialize an realavector object using a given array for the coefficients. More...

void	uninit_realavector (prealavector v)
	Uninitialize an realavector object. More...

prealavector	new_realavector (uint dim)
	Create a new realavector object. More...

prealavector	new_sub_realavector (prealavector src, uint dim, uint off)
	Create a new realavector object representing a subvector. More...

prealavector	new_pointer_realavector (preal src, uint dim)
	Create a new realavector object using a given array for the coefficients. More...

void	del_realavector (prealavector v)
	Delete an realavector object. More...

void	resize_realavector (prealavector v, uint dim)
	Change the dimension of an realavector object without preserving its coefficients. More...

void	shrink_realavector (prealavector v, uint dim)
	Reduce the dimension of an realavector object without reallocating storage, preserving its coefficients. More...

real	getentry_realavector (pcrealavector v, uint i)
	Read a vector entry . More...

void	setentry_realavector (prealavector v, uint i, real x)
	Set a vector entry, $v_i \gets x$ . More...

real	addentry_realavector (prealavector v, uint i, real x)
	Add to a vector entry, $v_i \gets v_i + x$ . More...

uint	getactives_realavector ()
	Get number of currently initialized realavector objects. More...

size_t	getsize_realavector (pcrealavector v)
	Get size of a given realavector object. More...

size_t	getsize_heap_realavector (pcrealavector v)
	Get heap size of a given realavector object. More...

void	clear_realavector (prealavector v)
	Set a vector to zero. More...

void	fill_realavector (prealavector v, real x)
	Set all coefficients in a vector to the same value. More...

void	random_realavector (prealavector v)
	Fill a vector with random values. More...

void	copy_realavector (pcrealavector v, prealavector w)
	Copy a vector into another vector, $w \gets v$ . More...

void	copy_sub_realavector (pcrealavector v, prealavector w)
	Copy a vector into another vector, $w \gets v$ . More...

void	print_realavector (pcrealavector v)
	Print a vector. More...

void	scale_realavector (real alpha, prealavector v)
	Scale a vector by a factor $\alpha$ , $v \gets \alpha v$ . More...

real	norm2_realavector (pcrealavector v)
	Compute the Euclidean norm $\\|v\\|_2$ of a vector . More...

real	dotprod_realavector (pcrealavector x, pcrealavector y)
	Compute the Euclidean innner product $\langle x, y\rangle_2$ of two vectors and . More...

void	add_realavector (real alpha, pcrealavector x, prealavector y)
	Add two vectors, $y \gets y + \alpha x$ . More...

Detailed Description

Representation of a vector as an array for real coefficients.

The realavector class is used to handle standard linear algebra operations like adding, scaling and multiplying vectors for real valued vectors.

Attention: If one needs to have a vector field entries from a general field, then the class avector should be used instead.

Typedef Documentation

typedef const realavector* pcrealavector

Pointer to a constant avector object.

typedef realavector* prealavector

Pointer to a avector object.

typedef struct _realavector realavector

Representation of a vector as an array.

Function Documentation

void add_realavector	(	real	alpha,
		pcrealavector	x,
		prealavector	y
	)

Add two vectors, $y \gets y + \alpha x$ .

Parameters

alpha	Scaling factor $\alpha$ .
x	Source vector .
y	Target vector .

real addentry_realavector	(	prealavector	v,
		uint	i,
		real	x
	)

Add to a vector entry, $v_i \gets v_i + x$ .

Parameters

v	Vector .
i	Index .
x	Summand.

Returns: New value of .

void clear_realavector ( prealavector v )

Set a vector to zero.

Parameters

v	Target vector.

void copy_realavector	(	pcrealavector	v,
		prealavector	w
	)

Copy a vector into another vector, $w \gets v$ .

Both vectors have to be of the same dimension.

Remarks: If you want to copy between vectors of different dimension, consider using copy_sub_realavector.

Parameters

v	Source vector.
w	Target vector.

void copy_sub_realavector	(	pcrealavector	v,
		prealavector	w
	)

Copy a vector into another vector, $w \gets v$ .

If $w$ is smaller than $v$ , only the first coefficients of $v$ are copied. If $v$ is smaller than $w$ , only the first coefficients of $w$ are filled.

Parameters

v	Source vector.
w	Target vector.

void del_realavector ( prealavector v )

Delete an realavector object.

Releases the storage corresponding to the object.

Attention: Make sure that there are no submatrix objects referring to this object, since they might otherwise keep using pointers to invalid storage.

Parameters

v	Object to be deleted.

real dotprod_realavector	(	pcrealavector	x,
		pcrealavector	y
	)

Compute the Euclidean innner product $\langle x, y\rangle_2$ of two vectors $x$ and $y$ .

The Euclidean inner product is given by $\langle x, y \rangle_2 = \sum_i x_i y_i$ .

Parameters

x	Vector .
y	Vector .

Returns: Euclidean inner product $\langle x, y\rangle_2$ .

void fill_realavector	(	prealavector	v,
		real	x
	)

Set all coefficients in a vector to the same value.

Parameters

v	Target vector.
x	Fill value.

uint getactives_realavector ( )

Get number of currently initialized realavector objects.

Calls to initialization functions like init_realavector and constructors like new_realavector increase an internal counter, while uninit_realavector and del_realavector decrease it.

Remarks: Use this function to check whether a program correctly cleans up temporary variables.

Returns: Number of currently initialized realavector objects.

real getentry_realavector	(	pcrealavector	v,
		uint	i
	)

Read a vector entry $v_i$ .

Parameters

v	Vector .
i	Index .

Returns: Vector entry .

size_t getsize_heap_realavector ( pcrealavector v )

Get heap size of a given realavector object.

Computes the size of storage allocated for the coefficients on the heap, but not for the realavector object itself. If the object uses the coefficients of another object (e.g., if it was created using new_sub_realavector), no storage is required.

Parameters

v	Vector object.

Returns: Size of allocated heap storage in bytes.

size_t getsize_realavector ( pcrealavector v )

Get size of a given realavector object.

Computes the size of the realavector object and the storage allocated for the coefficients. If the object uses the coefficients of another object (e.g., if it was created using new_sub_realavector), no coefficient storage is added.

Parameters

v	Vector object.

Returns: Size of allocated storage in bytes.

prealavector init_pointer_realavector	(	prealavector	v,
		preal	src,
		uint	dim
	)

Initialize an realavector object using a given array for the coefficients.

Sets up the components of the object and uses the given array to represent the coefficients.

Remarks: Should always be matched by a call to uninit_realavector that will not release the coefficient storage.

Parameters

v	Object to be initialized.
src	Source array, should contain at least `dim` elements.
dim	Dimension of the new vector.

Returns: Initialized realavector object.

prealavector init_realavector	(	prealavector	v,
		uint	dim
	)

Initialize an realavector object.

Sets up the components of the object and allocates storage for the coefficient array.

Remarks: Should always be matched by a call to uninit_realavector.

Parameters

v	Object to be initialized.
dim	Dimension of the new vector.

Returns: Initialized realavector object.

prealavector init_sub_realavector	(	prealavector	v,
		prealavector	src,
		uint	dim,
		uint	off
	)

Initialize an realavector object to represent a subvector.

Sets up the components of the object and uses part of the storage of another realavector for the coefficient array, leading to a new vector representing a subvector of the source. Changes to the coefficients of the new vector also change coefficients of the source vector.

Remarks: Should always be matched by a call to uninit_realavector that will not release the coefficient storage.

Parameters

v	Object to be initialized.
src	Source vector.
dim	Dimension of the new vector.
off	Offset in the source vector, should satisfy `dim+off<=src->dim`.

Returns: Initialized realavector object.

prealavector new_pointer_realavector	(	preal	src,
		uint	dim
	)

Create a new realavector object using a given array for the coefficients.

Parameters

src	Source array, should contain at least `dim` elements.
dim	Dimension of the new vector.

Returns: New realavector object.

prealavector new_realavector ( uint dim )

Create a new realavector object.

Allocates storage for the object an sets up its components.

Remarks: Should always be matched by a call to del_realavector.

Parameters

dim	Dimension of the new vector.

Returns: New realavector object.

prealavector new_sub_realavector	(	prealavector	src,
		uint	dim,
		uint	off
	)

Create a new realavector object representing a subvector.

Allocates storage for the object, but uses part of the storage of another realavector for the coefficient array, leading to a new vector representing a subvector of the source. Changes to the coefficients of the new vector also change coefficients of the source vector.

Remarks: Should always be matched by a call to del_realavector that will not release the coefficient storage.

Parameters

src	Source vector.
dim	Dimension of the new vector.
off	Offset in the source vector, should satisfy `dim+off<=src->dim`.

Returns: New realavector object.

real norm2_realavector ( pcrealavector v )

Compute the Euclidean norm $\|v\|_2$ of a vector $v$ .

Parameters

v Vector .

Returns: Returns $\|v\|_2$ .

void print_realavector ( pcrealavector v )

Print a vector.

Parameters

v Vector .

void random_realavector ( prealavector v )

Fill a vector with random values.

Parameters

v	Target vector.

void resize_realavector	(	prealavector	v,
		uint	dim
	)

Change the dimension of an realavector object without preserving its coefficients.

Allocates new storage for the coefficients and releases the old storage.

Attention: Make sure that there are no submatrix objects referring to this object, since they will otherwise keep using pointers to invalid storage.

Parameters

v	Vector to be resized.
dim	New vector dimension.

void scale_realavector	(	real	alpha,
		prealavector	v
	)

Scale a vector $v$ by a factor $\alpha$ , $v \gets \alpha v$ .

Parameters

alpha	Scaling factor $\alpha$ .
v	Target vector .

void setentry_realavector	(	prealavector	v,
		uint	i,
		real	x
	)

Set a vector entry, $v_i \gets x$ .

Parameters

v	Vector .
i	Index .
x	New value of .

void shrink_realavector	(	prealavector	v,
		uint	dim
	)

Reduce the dimension of an realavector object without reallocating storage, preserving its coefficients.

Parameters

v	Vector to be resized.
dim	New vector dimension, not greater than `v->dim`.

void uninit_realavector ( prealavector v )

Uninitialize an realavector object.

Invalidates pointers, freeing corresponding storage if appropriate, and prepares the object for deletion.

Parameters

v	Object to be uninitialized.

Data Structures

Typedefs

Functions

Detailed Description

Typedef Documentation

Function Documentation