Classe « lil_array »

Informations générales

Héritage

    builtins.object
        sparray
builtins.object
    IndexMixin
builtins.object
    _spbase
        _lil_base
            lil_array

Définition

class lil_array(_lil_base, sparray):

help(lil_array)

Row-based LIst of Lists sparse array.

This is a structure for constructing sparse arrays incrementally.
Note that inserting a single item can take linear time in the worst case;
to construct the array efficiently, make sure the items are pre-sorted by
index, per row.

This can be instantiated in several ways:
    lil_array(D)
        where D is a 2-D ndarray

    lil_array(S)
        with another sparse array or matrix S (equivalent to S.tolil())

    lil_array((M, N), [dtype])
        to construct an empty array with shape (M, N)
        dtype is optional, defaulting to dtype='d'.

Attributes
----------
dtype : dtype
    Data type of the array
shape : 2-tuple
    Shape of the array
ndim : int
    Number of dimensions (this is always 2)
nnz
size
data
    LIL format data array of the array
rows
    LIL format row index array of the array
T

Notes
-----
Sparse arrays can be used in arithmetic operations: they support
addition, subtraction, multiplication, division, and matrix power.

Advantages of the LIL format
    - supports flexible slicing
    - changes to the array sparsity structure are efficient

Disadvantages of the LIL format
    - arithmetic operations LIL + LIL are slow (consider CSR or CSC)
    - slow column slicing (consider CSC)
    - slow matrix vector products (consider CSR or CSC)

Intended Usage
    - LIL is a convenient format for constructing sparse arrays
    - once an array has been constructed, convert to CSR or
      CSC format for fast arithmetic and matrix vector operations
    - consider using the COO format when constructing large arrays

Data Structure
    - An array (``self.rows``) of rows, each of which is a sorted
      list of column indices of non-zero elements.
    - The corresponding nonzero values are stored in similar
      fashion in ``self.data``.

Constructeur(s)

Signature du constructeur	Description
__init__(self, arg1, shape=None, dtype=None, copy=False, *, maxprint=None)

Liste des propriétés

Nom de la propriété	Description
format	Format string for matrix. _{[extrait de format.__doc__]}
imag
ndim
nnz	Number of stored values, including explicit zeros. _{[extrait de nnz.__doc__]}
real
shape
size	Number of stored values. _{[extrait de size.__doc__]}
T	Transpose. _{[extrait de T.__doc__]}

Liste des opérateurs

Opérateurs hérités de la classe _lil_base

__getitem__, __iadd__, __imul__, __isub__, __itruediv__, __setitem__, __truediv__

Liste des opérateurs

Opérateurs hérités de la classe _spbase

__add__, __eq__, __ge__, __gt__, __le__, __lt__, __matmul__, __mul__, __ne__, __neg__, __pow__, __radd__, __rmul__, __rsub__, __rtruediv__, __sub__

Liste des méthodes

Toutes les méthodes Méthodes d'instance Méthodes statiques

Signature de la méthode	Description

Méthodes héritées de la classe sparray

__init_subclass__, __subclasshook__

Méthodes héritées de la classe _lil_base

copy, count_nonzero, getrow, getrowview, reshape, resize, toarray, tocsr, tolil, transpose

Méthodes héritées de la classe _spbase

__abs__, __bool__, __div__, __idiv__, __iter__, __len__, __nonzero__, __rdiv__, __repr__, __rmatmul__, __round__, __str__, asformat, astype, conj, conjugate, diagonal, dot, maximum, mean, minimum, multiply, nonzero, power, setdiag, sum, tobsr, tocoo, tocsc, todense, todia, todok, trace