Templated sparse vector class. More...
#include <itpp/base/svec.h>
Public Member Functions | |
Sparse_Vec () | |
Default constructor. | |
Sparse_Vec (int sz, int data_init=200) | |
Initiate an empty sparse vector. | |
Sparse_Vec (const Sparse_Vec< T > &v) | |
Initiate a new sparse vector. | |
Sparse_Vec (const Vec< T > &v) | |
Initiate a new sparse vector from a dense vector. | |
Sparse_Vec (const Vec< T > &v, T epsilon) | |
Initiate a new sparse vector from a dense vector. Elements of v larger than epsilon are copied into the new sparse vector. | |
~Sparse_Vec () | |
Destructor. | |
void | set_size (int sz, int data_init=-1) |
Set the size sz of the sparse vector. Default value data_init=-1 => allocated size for the data is not changed. | |
int | size () const |
Returns the size of the sparse vector. | |
int | nnz () |
Number of non-zero elements in the sparse vector. | |
double | density () |
Returns the density of the sparse vector: (number of non-zero elements)/(size of the vector) | |
void | set_small_element (const T &epsilon) |
Set that all elements smaller than epsilon should be set to zero. | |
void | remove_small_elements () |
void | resize_data (int new_size) |
Set the maximum number of non-zero elements to new_size . | |
void | compact () |
Set the maximum number of non-zero elements equal to the actual number of non-zero elements. | |
void | full (Vec< T > &v) const |
Returns a full, dense vector in v . | |
Vec< T > | full () const |
Returns a full, dense vector. | |
T | operator() (int i) const |
Returns the element with index i . | |
void | set (int i, T v) |
Set element i equal to v . | |
void | set (const ivec &index_vec, const Vec< T > &v) |
Set the elements of the sparse vector with indices index_vec to the values in v . | |
void | set_new (int i, T v) |
Set a new element with index i equal to v . | |
void | set_new (const ivec &index_vec, const Vec< T > &v) |
Set new elements with indices index_vec equal to the values in v (no check whether the same index is used several times) | |
void | add_elem (const int i, const T v) |
Add element i with v . | |
void | add (const ivec &index_vec, const Vec< T > &v) |
Add v to the elements specified by index_vec with v . | |
void | zeros () |
Set the sparse vector to the all zero vector (removes all non-zero elements) | |
void | zero_elem (const int i) |
Set the i-th element to zero (i.e. clear that element if it contains a non-zero value) | |
void | clear () |
Clear all non-zero elements of the sparse vector. | |
void | clear_elem (const int i) |
Clear the i-th element (if it contains a non-zero value) | |
void | get_nz_data (int p, T &data_out) |
Extract the reference to the p-th non-zero data element. | |
T | get_nz_data (int p) |
Returns the p-th non-zero data element. | |
int | get_nz_index (int p) |
Returns the vector index of the p-th non-zero element. | |
void | get_nz (int p, int &idx, T &dat) |
Returns the p-th non-zero value in dat and the corresponding vector index in idx . | |
ivec | get_nz_indices () |
Return the indices of non-zero values. | |
Sparse_Vec< T > | get_subvector (int i1, int i2) const |
Return sparse subvector from index i1 to index i2 . | |
T | sqr () const |
Returns the sum of all values squared. | |
void | operator= (const Sparse_Vec< T > &v) |
Assign sparse vector the value and length of the sparse vector v . | |
void | operator= (const Vec< T > &v) |
Assign sparse vector the value and length of the dense vector v . | |
Sparse_Vec< T > | operator- () const |
Returns the sign inverse of all elements in the sparse vector. | |
bool | operator== (const Sparse_Vec< T > &v) |
Compare two sparse vectors. False if wrong sizes or different values. | |
void | operator+= (const Sparse_Vec< T > &v) |
Add sparse vector v to all non-zero elements of the sparse vector. | |
void | operator+= (const Vec< T > &v) |
Add vector v to all non-zero elements of the sparse vector. | |
void | operator-= (const Sparse_Vec< T > &v) |
Subtract sparse vector v from all non-zero elements of the sparse vector. | |
void | operator-= (const Vec< T > &v) |
Subtract vector v from all non-zero elements of the sparse vector. | |
void | operator*= (const T &v) |
Multiply the scalar v to all non-zero elements of the sparse vector. | |
void | operator/= (const T &v) |
Divide all non-zero elements of the sparse vector with the scalar v . | |
Friends | |
Sparse_Vec< T > | operator+ (const Sparse_Vec< T > &v1, const Sparse_Vec< T > &v2) |
Addition v1+v2 where v1 and v2 are sparse vector. | |
T | operator* (const Sparse_Vec< T > &v1, const Sparse_Vec< T > &v2) |
Scalar product v1*v2 where v1 and v2 are sparse vectors. | |
T | operator* (const Sparse_Vec< T > &v1, const Vec< T > &v2) |
Scalar product v1*v2 where v1 is a sparse vector and v2 is a dense vector. | |
T | operator* (const Vec< T > &v1, const Sparse_Vec< T > &v2) |
Scalar product v1*v2 where v1 is a dense vector and v2 is a sparse vector. | |
Sparse_Vec< T > | elem_mult (const Sparse_Vec< T > &v1, const Sparse_Vec< T > &v2) |
Element wise multiplication of two sparse vectors. | |
Vec< T > | elem_mult (const Sparse_Vec< T > &v1, const Vec< T > &v2) |
Element wise multiplication of a sparse vector and a dense vector. | |
Sparse_Vec< T > | elem_mult_s (const Sparse_Vec< T > &v1, const Vec< T > &v2) |
Element wise multiplication of a sparse vector and a dense vector returning a sparse vector. | |
Vec< T > | elem_mult (const Vec< T > &v1, const Sparse_Vec< T > &v2) |
Element wise multiplication of a a dense vector and a sparse vector. | |
Sparse_Vec< T > | elem_mult_s (const Vec< T > &v1, const Sparse_Vec< T > &v2) |
Element wise multiplication of a a dense vector and a sparse vector returning a sparse vector. | |
Templated sparse vector class.
A sparse vector is a vector where most elements are zero. The maximum number of none-zero elements is a parameter to the constructor. The elements are stored in random order, i.e. they are not sorted.
Sparse_Vec< T >::Sparse_Vec | ( | int | sz, |
int | data_init = 200 |
||
) |
Sparse_Vec< T >::Sparse_Vec | ( | const Sparse_Vec< T > & | v | ) |
Sparse_Vec< T >::Sparse_Vec | ( | const Vec< T > & | v | ) |
Initiate a new sparse vector from a dense vector.
v | The elements of v are copied into the new sparse vector |
Definition at line 421 of file svec.h.
References itpp::min(), and itpp::Vec< Num_T >::size().
Sparse_Vec< T >::Sparse_Vec | ( | const Vec< T > & | v, |
T | epsilon | ||
) |
Initiate a new sparse vector from a dense vector. Elements of v
larger than epsilon
are copied into the new sparse vector.
v
larger than abs(epsilon)
are copied into the new sparse vector. Definition at line 442 of file svec.h.
References itpp::abs(), itpp::eps, itpp::min(), and itpp::Vec< Num_T >::size().
void Sparse_Vec< T >::set_size | ( | int | sz, |
int | data_init = -1 |
||
) |
Set the size sz
of the sparse vector. Default value data_init=-1
=>
allocated size for the data is not changed.
sz | Size of the sparse vector (i.e. maximum index is (sz - 1)) |
data_init | Maximum number of non-zero elements in the sparse vector (default value -1 => allocated size for the data is not changed) |
void Sparse_Vec< T >::remove_small_elements | ( | ) |
Removes all elements that are smaller than epsilon from the non-zero elements.
epsilon=0
. Definition at line 499 of file svec.h.
References itpp::abs(), and itpp::eps.
Referenced by itpp::Sparse_Vec< bin >::get_nz(), itpp::Sparse_Vec< bin >::get_nz_data(), itpp::Sparse_Vec< bin >::get_nz_index(), and itpp::Sparse_Vec< bin >::nnz().
void Sparse_Vec< T >::resize_data | ( | int | new_size | ) |
Set the maximum number of non-zero elements to new_size
.
new_size | The new maximum number of non-zero elements. |
Definition at line 524 of file svec.h.
References it_assert.
Referenced by itpp::elem_mult(), itpp::Sparse_Vec< T >::get_subvector(), and itpp::operator+().
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