GNU Octave  9.1.0
A high-level interpreted language, primarily intended for numerical computations, mostly compatible with Matlab
dim_vector Class Reference

Vector representing the dimensions (size) of an Array. More...

#include "dim-vector.h"

Public Member Functions

 dim_vector ()
 
 dim_vector (const dim_vector &dv)
 
template<typename... Ints>
 dim_vector (const octave_idx_type r, const octave_idx_type c, Ints... lengths)
 Construct dim_vector for a N dimensional array. More...
 
 dim_vector (dim_vector &&dv)
 
 ~dim_vector ()
 
bool all_ones () const
 
bool all_zero () const
 
bool any_neg () const
 
bool any_zero () const
 
Array< octave_idx_typeas_array () const
 
dim_vector as_column () const
 
dim_vector as_row () const
 
void chop_all_singletons ()
 
void chop_trailing_singletons ()
 
octave_idx_type compute_index (const octave_idx_type *idx) const
 Linear index from an index tuple. More...
 
octave_idx_type compute_index (const octave_idx_type *idx, int nidx) const
 Linear index from an incomplete index tuple (nidx < length ()). More...
 
bool concat (const dim_vector &dvb, int dim)
 This corresponds to cat(). More...
 
octave_idx_type cum_compute_index (const octave_idx_type *idx) const
 Compute a linear index from an index tuple. More...
 
dim_vector cumulative () const
 Return cumulative dimensions. More...
 
octave_idx_typeelem (int i)
 
octave_idx_type elem (int i) const
 
bool empty_2d () const
 
int first_non_singleton (int def=0) const
 
bool hvcat (const dim_vector &dvb, int dim)
 This corresponds to [,] (horzcat, dim = 0) and [;] (vertcat, dim = 1). More...
 
int increment_index (octave_idx_type *idx, int start=0) const
 Increment a multi-dimensional index tuple, optionally starting from an offset position and return the index of the last index position that was changed, or length () if just cycled over. More...
 
bool is_nd_vector () const
 
bool isvector () const
 
int length () const
 Number of dimensions. More...
 
dim_vector make_nd_vector (octave_idx_type n) const
 
octave_idx_type ndims () const
 Number of dimensions. More...
 
int num_ones () const
 
octave_idx_type numel (int n=0) const
 Number of elements that a matrix with this dimensions would have. More...
 
octave_idx_typeoperator() (int i)
 
octave_idx_type operator() (int i) const
 
dim_vectoroperator= (const dim_vector &dv)
 
dim_vectoroperator= (dim_vector &&dv)
 
dim_vector redim (int n) const
 Force certain dimensionality, preserving numel (). More...
 
void resize (int n, int fill_value=0)
 
octave_idx_type safe_numel () const
 The following function will throw a std::bad_alloc () exception if the requested size is larger than can be indexed by octave_idx_type. More...
 
dim_vector squeeze () const
 
std::string str (char sep='x') const
 
octave_idx_typexelem (int i)
 
octave_idx_type xelem (int i) const
 
bool zero_by_zero () const
 

Static Public Member Functions

static dim_vector alloc (int n)
 
static octave_idx_type dim_max ()
 

Friends

bool operator== (const dim_vector &a, const dim_vector &b)
 

Detailed Description

Vector representing the dimensions (size) of an Array.

A dim_vector is used to represent dimensions of an Array. It is used on its constructor to specify its size, or when reshaping it.

// Matrix with 10 rows and 20 columns.
// Change its size to 5 rows and 40 columns.
Matrix m2 = m.reshape (dim_vector (5, 40));
// Five dimensional Array of length 10, 20, 3, 8, 7 on each dimension.
NDArray a (dim_vector (10, 20, 3, 8, 7));
// Uninitialized array of same size as other.
NDArray b (a.dims ());
Definition: dMatrix.h:42
Vector representing the dimensions (size) of an Array.
Definition: dim-vector.h:94
T octave_idx_type m
Definition: mx-inlines.cc:781

The main thing to understand about this class, is that methods such as ndims() and numel(), return the value for an Array of these dimensions, not the actual number of elements in the dim_vector.

dim_vector d (10, 5, 3);
octave_idx_type n = d.numel (); // returns 150
octave_idx_type nd = d.ndims (); // returns 3
F77_RET_T const F77_DBLE const F77_DBLE F77_DBLE * d
octave_idx_type n
Definition: mx-inlines.cc:761

Implementation details

This implementation is more tricky than Array, but the big plus is that dim_vector requires only one allocation instead of two. It is (slightly) patterned after GCC's basic_string implementation. rep is a pointer to an array of memory, comprising count, length, and the data:

//!        <count>
//!        <ndims>
//! rep --> <dims[0]>
//!        <dims[1]>
//!        ...
//! 
The inlines count(), ndims() recover this data from the rep.  Note
that rep points to the beginning of dims to grant faster access
(reinterpret_cast is assumed to be an inexpensive operation). 

Definition at line 91 of file dim-vector.h.

Constructor & Destructor Documentation

◆ dim_vector() [1/4]

template<typename... Ints>
dim_vector::dim_vector ( const octave_idx_type  r,
const octave_idx_type  c,
Ints...  lengths 
)
inline

Construct dim_vector for a N dimensional array.

Each argument to constructor defines the length of an additional dimension. A dim_vector always represents a minimum of 2 dimensions (just like an Array has at least 2 dimensions) and there is no upper limit on the number of dimensions.

dim_vector dv (7, 5);
Matrix mat (dv);

The constructed dim_vector dv will have two elements, $[7, 5]$, one for each dimension. It can then be used to construct a Matrix with such dimensions, i.e., 7 rows and 5 columns.

NDArray x (dim_vector (7, 5, 10));
F77_RET_T const F77_DBLE * x

This will construct a 3 dimensional NDArray of lengths 7, 5, and 10, on the first, second, and third dimension (rows, columns, and pages) respectively.

Note that that there is no constructor that accepts only one dimension length to avoid confusion. The source for such confusion is that constructor could mean:

  • a column vector, i.e., assume $[N, 1]$;
  • a square matrix, i.e., as is common in Octave interpreter;
  • support for a 1 dimensional Array (does not exist);

Using r, c, and lengths... as arguments, allow us to check at compile time that there's at least 2 dimensions specified, while maintaining type safety.

Definition at line 139 of file dim-vector.h.

References r.

◆ dim_vector() [2/4]

dim_vector::dim_vector ( )
inlineexplicit

Definition at line 184 of file dim-vector.h.

Referenced by hvcat().

◆ dim_vector() [3/4]

dim_vector::dim_vector ( const dim_vector dv)
inline

Definition at line 190 of file dim-vector.h.

◆ dim_vector() [4/4]

dim_vector::dim_vector ( dim_vector &&  dv)
inline

Definition at line 196 of file dim-vector.h.

◆ ~dim_vector()

dim_vector::~dim_vector ( )
inline

Definition at line 242 of file dim-vector.h.

Member Function Documentation

◆ all_ones()

◆ all_zero()

bool dim_vector::all_zero ( ) const
inline

Definition at line 300 of file dim-vector.h.

Referenced by octave_map::concat(), and Ffind().

◆ alloc()

static dim_vector dim_vector::alloc ( int  n)
inlinestatic

◆ any_neg()

bool dim_vector::any_neg ( ) const
inline

Definition at line 357 of file dim-vector.h.

Referenced by Array< T, Alloc >::resize().

◆ any_zero()

◆ as_array()

Array< octave_idx_type > dim_vector::as_array ( ) const

Definition at line 266 of file dim-vector.cc.

References elem(), and ndims().

Referenced by octave_base_value::dump().

◆ as_column()

dim_vector dim_vector::as_column ( ) const
inline

Definition at line 379 of file dim-vector.h.

References numel().

Referenced by Ffind().

◆ as_row()

dim_vector dim_vector::as_row ( ) const
inline

Definition at line 387 of file dim-vector.h.

References numel().

Referenced by squeeze().

◆ chop_all_singletons()

void dim_vector::chop_all_singletons ( )

Definition at line 50 of file dim-vector.cc.

References ndims(), and xelem().

Referenced by Array< T, Alloc >::assign(), squeeze(), and zero_dims_inquire().

◆ chop_trailing_singletons()

void dim_vector::chop_trailing_singletons ( )
inline

◆ compute_index() [1/2]

octave_idx_type dim_vector::compute_index ( const octave_idx_type idx) const
inline

Linear index from an index tuple.

Definition at line 456 of file dim-vector.h.

References compute_index().

Referenced by Array< T, Alloc >::compute_index_unchecked(), do_bsxfun_op(), and do_inplace_bsxfun_op().

◆ compute_index() [2/2]

octave_idx_type dim_vector::compute_index ( const octave_idx_type idx,
int  nidx 
) const
inline

Linear index from an incomplete index tuple (nidx < length ()).

Definition at line 460 of file dim-vector.h.

◆ concat()

bool dim_vector::concat ( const dim_vector dvb,
int  dim 
)

This corresponds to cat().

Definition at line 140 of file dim-vector.cc.

References chop_trailing_singletons(), ndims(), resize(), and xelem().

Referenced by Array< T, Alloc >::cat(), Sparse< T, Alloc >::cat(), and hvcat().

◆ cum_compute_index()

octave_idx_type dim_vector::cum_compute_index ( const octave_idx_type idx) const
inline

Compute a linear index from an index tuple.

Dimensions are required to be cumulative.

Definition at line 503 of file dim-vector.h.

Referenced by do_bsxfun_op(), and do_inplace_bsxfun_op().

◆ cumulative()

dim_vector dim_vector::cumulative ( ) const
inline

Return cumulative dimensions.

Definition at line 488 of file dim-vector.h.

References xelem().

Referenced by do_bsxfun_op(), and do_inplace_bsxfun_op().

◆ dim_max()

octave_idx_type dim_vector::dim_max ( )
static

Definition at line 44 of file dim-vector.cc.

References max().

Referenced by Fsizemax().

◆ elem() [1/2]

octave_idx_type& dim_vector::elem ( int  i)
inline

Definition at line 157 of file dim-vector.h.

Referenced by as_array(), and squeeze().

◆ elem() [2/2]

octave_idx_type dim_vector::elem ( int  i) const
inline

Definition at line 162 of file dim-vector.h.

◆ empty_2d()

bool dim_vector::empty_2d ( ) const
inline

Definition at line 306 of file dim-vector.h.

◆ first_non_singleton()

int dim_vector::first_non_singleton ( int  def = 0) const
inline

◆ hvcat()

bool dim_vector::hvcat ( const dim_vector dvb,
int  dim 
)

This corresponds to [,] (horzcat, dim = 0) and [;] (vertcat, dim = 1).

Definition at line 201 of file dim-vector.cc.

References dim_vector(), concat(), ndims(), and xelem().

Referenced by Array< T, Alloc >::cat(), and Sparse< T, Alloc >::cat().

◆ increment_index()

int dim_vector::increment_index ( octave_idx_type idx,
int  start = 0 
) const
inline

Increment a multi-dimensional index tuple, optionally starting from an offset position and return the index of the last index position that was changed, or length () if just cycled over.

Definition at line 473 of file dim-vector.h.

Referenced by do_bsxfun_op(), and do_inplace_bsxfun_op().

◆ is_nd_vector()

bool dim_vector::is_nd_vector ( ) const
inline

Definition at line 400 of file dim-vector.h.

Referenced by Array< T, Alloc >::is_nd_vector().

◆ isvector()

bool dim_vector::isvector ( ) const
inline

◆ length()

int dim_vector::length ( ) const
inline

Number of dimensions.

Synonymous with ndims().

While this method is not officially deprecated, consider using ndims() instead to avoid confusion. Array does not have length because of its odd definition as length of the longest dimension.

Definition at line 266 of file dim-vector.h.

◆ make_nd_vector()

dim_vector dim_vector::make_nd_vector ( octave_idx_type  n) const
inline

Definition at line 421 of file dim-vector.h.

References n, and ndims().

Referenced by Array< octave_value * >::assign().

◆ ndims()

octave_idx_type dim_vector::ndims ( ) const
inline

Number of dimensions.

Returns the number of dimensions of the dim_vector. This is number of elements in the dim_vector including trailing singletons. It is also the number of dimensions an Array with this dim_vector would have.

Definition at line 257 of file dim-vector.h.

Referenced by Sparse< T, Alloc >::Sparse(), all_colon_equiv(), as_array(), Array< T, Alloc >::as_column(), Array< T, Alloc >::as_matrix(), Array< T, Alloc >::as_row(), Array< T, Alloc >::assign(), Array< T, Alloc >::cat(), octave::check_dimensions(), chop_all_singletons(), octave_uint64_matrix::complex_matrix_value(), concat(), Array< T, Alloc >::diag(), Array< T, Alloc >::dim3(), Fellipj(), Ffilter(), filter(), Flinspace(), octave_uint64_matrix::float_complex_matrix_value(), octave_uint64_matrix::float_matrix_value(), ComplexNDArray::fourier(), NDArray::fourier(), FloatComplexNDArray::fourier(), FloatNDArray::fourier(), NDArray::fourier2d(), FloatComplexNDArray::fourier2d(), FloatNDArray::fourier2d(), ComplexNDArray::fourierNd(), NDArray::fourierNd(), FloatComplexNDArray::fourierNd(), FloatNDArray::fourierNd(), freeze(), Fsize(), Fstruct2cell(), get_ra_idx(), hvcat(), ComplexNDArray::ifourier(), NDArray::ifourier(), FloatComplexNDArray::ifourier(), FloatNDArray::ifourier(), ComplexNDArray::ifourier2d(), NDArray::ifourier2d(), FloatComplexNDArray::ifourier2d(), ComplexNDArray::ifourierNd(), NDArray::ifourierNd(), FloatComplexNDArray::ifourierNd(), FloatNDArray::ifourierNd(), increment_index(), ind2sub(), index_in_bounds(), ComplexNDArray::insert(), FloatComplexNDArray::insert(), is_scalar(), is_valid_bsxfun(), is_valid_inplace_bsxfun(), isvector(), make_nd_vector(), octave_uint64_matrix::matrix_value(), SparseComplexMatrix::max(), SparseMatrix::max(), SparseComplexMatrix::min(), SparseMatrix::min(), octave_base_value::ndims(), Array< T, Alloc >::ndims(), Sparse< T, Alloc >::ndims(), num_ones(), operator<<(), Array< T, Alloc >::permute(), Array< octave_value * >::permute(), redim(), Sparse< T, Alloc >::reshape(), Sparse< T, Alloc >::resize(), octave_base_diag< DMT, MT >::resize(), Array< T, Alloc >::resize(), octave_base_int_matrix< T >::save_ascii(), octave_bool_matrix::save_ascii(), octave_cell::save_ascii(), octave_complex_matrix::save_ascii(), octave_float_complex_matrix::save_ascii(), octave_float_matrix::save_ascii(), octave_matrix::save_ascii(), octave_char_matrix_str::save_ascii(), octave_struct::save_ascii(), octave_scalar_struct::save_ascii(), octave_bool_matrix::save_binary(), octave_sparse_bool_matrix::save_binary(), octave_cell::save_binary(), octave_complex_matrix::save_binary(), octave_sparse_complex_matrix::save_binary(), octave_float_complex_matrix::save_binary(), octave_float_matrix::save_binary(), octave_matrix::save_binary(), octave_sparse_matrix::save_binary(), octave_char_matrix_str::save_binary(), octave_struct::save_binary(), octave_base_int_matrix< T >::save_binary(), octave_bool_matrix::save_hdf5(), octave_cell::save_hdf5(), octave_complex_matrix::save_hdf5(), octave_float_complex_matrix::save_hdf5(), octave_float_matrix::save_hdf5(), octave_matrix::save_hdf5(), octave_char_matrix_str::save_hdf5(), octave_base_int_matrix< T >::save_hdf5_internal(), octave_base_value::size(), octave_class::size(), Array< T, Alloc >::sort(), octave_lazy_index::sort(), squeeze(), str(), vector_equivalent(), and zero_dims_inquire().

◆ num_ones()

int dim_vector::num_ones ( ) const

Definition at line 86 of file dim-vector.cc.

References ndims(), and xelem().

◆ numel()

octave_idx_type dim_vector::numel ( int  n = 0) const
inline

Number of elements that a matrix with this dimensions would have.

Return the number of elements that a matrix with this dimension vector would have, NOT the number of dimensions (elements in the dimension vector).

Definition at line 335 of file dim-vector.h.

References n.

Referenced by airy(), biry(), compute_index(), octave_float_matrix::convert_to_str_internal(), octave_matrix::convert_to_str_internal(), octave_sparse_matrix::convert_to_str_internal(), octave::dims_to_numel(), do_bessel(), do_bsxfun_op(), do_inplace_bsxfun_op(), fftw::fftNd(), filter(), Fregexprep(), Freshape(), octave::get_dimensions(), get_ra_idx(), fftw::ifftNd(), ind2sub(), octave_base_matrix< MT >::is_true(), octave_perm_matrix::is_true(), octave_cell::load_ascii(), octave_char_matrix_str::load_ascii(), octave_bool_matrix::load_binary(), octave_cell::load_binary(), octave_complex_matrix::load_binary(), octave_float_complex_matrix::load_binary(), octave_float_matrix::load_binary(), octave_matrix::load_binary(), octave_char_matrix_str::load_binary(), octave_base_int_matrix< T >::load_binary(), octave_bool_matrix::load_hdf5(), octave_cell::load_hdf5(), octave_base_value::numel(), octave_class::numel(), Sparse< T, Alloc >::reshape(), octave_bool::resize(), octave_complex::resize(), octave_float_scalar::resize(), octave_float_complex::resize(), octave_uint64_scalar::resize(), octave_scalar::resize(), octave_cell::save_ascii(), octave_char_matrix_str::save_ascii(), octave_cell::save_binary(), octave_complex_matrix::save_binary(), octave_float_complex_matrix::save_binary(), octave_float_matrix::save_binary(), octave_matrix::save_binary(), octave_char_matrix_str::save_binary(), octave_cell::save_hdf5(), octave_char_matrix_str::save_hdf5(), Array< T, Alloc >::sort(), and octave_cell::subsasgn().

◆ operator()() [1/2]

octave_idx_type& dim_vector::operator() ( int  i)
inline

Definition at line 268 of file dim-vector.h.

◆ operator()() [2/2]

octave_idx_type dim_vector::operator() ( int  i) const
inline

Definition at line 270 of file dim-vector.h.

◆ operator=() [1/2]

dim_vector& dim_vector::operator= ( const dim_vector dv)
inline

Definition at line 207 of file dim-vector.h.

◆ operator=() [2/2]

dim_vector& dim_vector::operator= ( dim_vector &&  dv)
inline

Definition at line 222 of file dim-vector.h.

◆ redim()

dim_vector dim_vector::redim ( int  n) const

Force certain dimensionality, preserving numel ().

Missing dimensions are set to 1, redundant are folded into the trailing one. If n = 1, the result is 2d and the second dim is 1 (dim_vectors are always at least 2D).

Definition at line 226 of file dim-vector.cc.

References alloc(), n, ndims(), and xelem().

Referenced by Array< T, Alloc >::as_matrix(), Array< T, Alloc >::assign(), octave_base_matrix< MT >::assign(), compute_index(), octave::dims_to_numel(), do_bsxfun_op(), do_inplace_bsxfun_op(), Fdot(), Fsize(), MArray< T >::idx_add_nd(), Sparse< T, Alloc >::index(), Array< T, Alloc >::index(), Array< T, Alloc >::insert(), Array< T, Alloc >::resize(), sub2ind(), octave_cell::subsasgn(), and tree_evaluator::visit_simple_for_command().

◆ resize()

◆ safe_numel()

octave_idx_type dim_vector::safe_numel ( ) const

The following function will throw a std::bad_alloc () exception if the requested size is larger than can be indexed by octave_idx_type.

This may be smaller than the actual amount of memory that can be safely allocated on a system. However, if we don't fail here, we can end up with a mysterious crash inside a function that is iterating over an array using octave_idx_type indices.

Definition at line 98 of file dim-vector.cc.

Referenced by Array< T, Alloc >::Array(), Sparse< T, Alloc >::Sparse(), Array< T, Alloc >::clear(), octave_base_sparse< T >::numel(), and Sparse< T, Alloc >::numel().

◆ squeeze()

dim_vector dim_vector::squeeze ( ) const

Definition at line 117 of file dim-vector.cc.

References as_row(), chop_all_singletons(), elem(), ndims(), and xelem().

Referenced by octave_map::squeeze().

◆ str()

◆ xelem() [1/2]

octave_idx_type& dim_vector::xelem ( int  i)
inline

Definition at line 151 of file dim-vector.h.

Referenced by chop_all_singletons(), concat(), cumulative(), hvcat(), num_ones(), redim(), squeeze(), and str().

◆ xelem() [2/2]

octave_idx_type dim_vector::xelem ( int  i) const
inline

Definition at line 153 of file dim-vector.h.

◆ zero_by_zero()

bool dim_vector::zero_by_zero ( ) const
inline

Friends And Related Function Documentation

◆ operator==

bool operator== ( const dim_vector a,
const dim_vector b 
)
friend

Definition at line 520 of file dim-vector.h.


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