|
"""Base class for sparse matrices"""
get_sum_dtype, validateaxis, check_reshape_kwargs, check_shape, asmatrix)
'SparseWarning', 'SparseEfficiencyWarning']
# The formats that we might potentially understand. 'csr': [1, "Compressed Sparse Row"], 'dok': [2, "Dictionary Of Keys"], 'lil': [3, "LInked List"], 'dod': [4, "Dictionary of Dictionaries"], 'sss': [5, "Symmetric Sparse Skyline"], 'coo': [6, "COOrdinate"], 'lba': [7, "Linpack BAnded"], 'egd': [8, "Ellpack-itpack Generalized Diagonal"], 'dia': [9, "DIAgonal"], 'bsr': [10, "Block Sparse Row"], 'msr': [11, "Modified compressed Sparse Row"], 'bsc': [12, "Block Sparse Column"], 'msc': [13, "Modified compressed Sparse Column"], 'ssk': [14, "Symmetric SKyline"], 'nsk': [15, "Nonsymmetric SKyline"], 'jad': [16, "JAgged Diagonal"], 'uss': [17, "Unsymmetric Sparse Skyline"], 'vbr': [18, "Variable Block Row"], 'und': [19, "Undefined"] }
# These univariate ufuncs preserve zeros. np.sin, np.tan, np.arcsin, np.arctan, np.sinh, np.tanh, np.arcsinh, np.arctanh, np.rint, np.sign, np.expm1, np.log1p, np.deg2rad, np.rad2deg, np.floor, np.ceil, np.trunc, np.sqrt])
""" This class provides a base class for all sparse matrices. It cannot be instantiated. Most of the work is provided by subclasses. """
self._shape = None if self.__class__.__name__ == 'spmatrix': raise ValueError("This class is not intended" " to be instantiated directly.") self.maxprint = maxprint
"""See `reshape`.""" # Make sure copy is False since this is in place # Make sure format is unchanged because we are doing a __dict__ swap new_matrix = self.reshape(shape, copy=False).asformat(self.format) self.__dict__ = new_matrix.__dict__
"""Get shape of a matrix.""" return self._shape
"""reshape(self, shape, order='C', copy=False)
Gives a new shape to a sparse matrix without changing its data.
Parameters ---------- shape : length-2 tuple of ints The new shape should be compatible with the original shape. order : {'C', 'F'}, optional Read the elements using this index order. 'C' means to read and write the elements using C-like index order; e.g. read entire first row, then second row, etc. 'F' means to read and write the elements using Fortran-like index order; e.g. read entire first column, then second column, etc. copy : bool, optional Indicates whether or not attributes of self should be copied whenever possible. The degree to which attributes are copied varies depending on the type of sparse matrix being used.
Returns ------- reshaped_matrix : sparse matrix A sparse matrix with the given `shape`, not necessarily of the same format as the current object.
See Also -------- np.matrix.reshape : NumPy's implementation of 'reshape' for matrices """ # If the shape already matches, don't bother doing an actual reshape # Otherwise, the default is to convert to COO and use its reshape shape = check_shape(args, self.shape) order, copy = check_reshape_kwargs(kwargs) if shape == self.shape: if copy: return self.copy() else: return self
return self.tocoo(copy=copy).reshape(shape, order=order, copy=False)
"""Resize the matrix in-place to dimensions given by ``shape``
Any elements that lie within the new shape will remain at the same indices, while non-zero elements lying outside the new shape are removed.
Parameters ---------- shape : (int, int) number of rows and columns in the new matrix
Notes ----- The semantics are not identical to `numpy.ndarray.resize` or `numpy.resize`. Here, the same data will be maintained at each index before and after reshape, if that index is within the new bounds. In numpy, resizing maintains contiguity of the array, moving elements around in the logical matrix but not within a flattened representation.
We give no guarantees about whether the underlying data attributes (arrays, etc.) will be modified in place or replaced with new objects. """ # As an inplace operation, this requires implementation in each format. raise NotImplementedError( '{}.resize is not implemented'.format(type(self).__name__))
"""Cast the matrix elements to a specified type.
Parameters ---------- dtype : string or numpy dtype Typecode or data-type to which to cast the data. casting : {'no', 'equiv', 'safe', 'same_kind', 'unsafe'}, optional Controls what kind of data casting may occur. Defaults to 'unsafe' for backwards compatibility. 'no' means the data types should not be cast at all. 'equiv' means only byte-order changes are allowed. 'safe' means only casts which can preserve values are allowed. 'same_kind' means only safe casts or casts within a kind, like float64 to float32, are allowed. 'unsafe' means any data conversions may be done. copy : bool, optional If `copy` is `False`, the result might share some memory with this matrix. If `copy` is `True`, it is guaranteed that the result and this matrix do not share any memory. """
dtype = np.dtype(dtype) if self.dtype != dtype: return self.tocsr().astype( dtype, casting=casting, copy=copy).asformat(self.format) elif copy: return self.copy() else: return self
"""Upcast matrix to a floating point format (if necessary)"""
fp_types = ['f', 'd', 'F', 'D']
if self.dtype.char in fp_types: return self else: for fp_type in fp_types: if self.dtype <= np.dtype(fp_type): return self.astype(fp_type)
raise TypeError('cannot upcast [%s] to a floating ' 'point format' % self.dtype.name)
for r in xrange(self.shape[0]): yield self[r, :]
"""Maximum number of elements to display when printed.""" return self.maxprint
"""Number of non-zero entries, equivalent to
np.count_nonzero(a.toarray())
Unlike getnnz() and the nnz property, which return the number of stored entries (the length of the data attribute), this method counts the actual number of non-zero entries in data. """ raise NotImplementedError("count_nonzero not implemented for %s." % self.__class__.__name__)
"""Number of stored values, including explicit zeros.
Parameters ---------- axis : None, 0, or 1 Select between the number of values across the whole matrix, in each column, or in each row.
See also -------- count_nonzero : Number of non-zero entries """ raise NotImplementedError("getnnz not implemented for %s." % self.__class__.__name__)
def nnz(self): """Number of stored values, including explicit zeros.
See also -------- count_nonzero : Number of non-zero entries """ return self.getnnz()
"""Format of a matrix representation as a string.""" return getattr(self, 'format', 'und')
def __repr__(self): _, format_name = _formats[self.getformat()] return "<%dx%d sparse matrix of type '%s'\n" \ "\twith %d stored elements in %s format>" % \ (self.shape + (self.dtype.type, self.nnz, format_name))
def __str__(self): maxprint = self.getmaxprint()
A = self.tocoo()
# helper function, outputs "(i,j) v" def tostr(row, col, data): triples = zip(list(zip(row, col)), data) return '\n'.join([(' %s\t%s' % t) for t in triples])
if self.nnz > maxprint: half = maxprint // 2 out = tostr(A.row[:half], A.col[:half], A.data[:half]) out += "\n :\t:\n" half = maxprint - maxprint//2 out += tostr(A.row[-half:], A.col[-half:], A.data[-half:]) else: out = tostr(A.row, A.col, A.data)
return out
if self.shape == (1, 1): return self.nnz != 0 else: raise ValueError("The truth value of an array with more than one " "element is ambiguous. Use a.any() or a.all().")
# What should len(sparse) return? For consistency with dense matrices, # perhaps it should be the number of rows? But for some uses the number of # non-zeros is more important. For now, raise an exception! raise TypeError("sparse matrix length is ambiguous; use getnnz()" " or shape[0]")
"""Return this matrix in the passed sparse format.
Parameters ---------- format : {str, None} The desired sparse matrix format ("csr", "csc", "lil", "dok", ...) or None for no conversion. copy : bool, optional If True, the result is guaranteed to not share data with self.
Returns ------- A : This matrix in the passed sparse format.
""" if format is None or format == self.format: if copy: return self.copy() else: return self else: try: convert_method = getattr(self, 'to' + format) except AttributeError: raise ValueError('Format {} is unknown.'.format(format)) else: return convert_method(copy=copy)
################################################################### # NOTE: All arithmetic operations use csr_matrix by default. # Therefore a new sparse matrix format just needs to define a # .tocsr() method to provide arithmetic support. Any of these # methods can be overridden for efficiency. ####################################################################
"""Point-wise multiplication by another matrix """ return self.tocsr().multiply(other)
"""Element-wise maximum between this and another matrix.""" return self.tocsr().maximum(other)
"""Element-wise minimum between this and another matrix.""" return self.tocsr().minimum(other)
"""Ordinary dot product
Examples -------- >>> import numpy as np >>> from scipy.sparse import csr_matrix >>> A = csr_matrix([[1, 2, 0], [0, 0, 3], [4, 0, 5]]) >>> v = np.array([1, 0, -1]) >>> A.dot(v) array([ 1, -3, -1], dtype=int64)
""" return self * other
"""Element-wise power.""" return self.tocsr().power(n, dtype=dtype)
return self.tocsr().__eq__(other)
return self.tocsr().__ne__(other)
return self.tocsr().__lt__(other)
return self.tocsr().__gt__(other)
return self.tocsr().__le__(other)
return self.tocsr().__ge__(other)
return abs(self.tocsr())
return self.tocsr()._add_sparse(other)
return self.tocoo()._add_dense(other)
return self.tocsr()._sub_sparse(other)
return self.todense() - other
# note: this can't be replaced by other + (-self) for unsigned types return other - self.todense()
if isscalarlike(other): if other == 0: return self.copy() # Now we would add this scalar to every element. raise NotImplementedError('adding a nonzero scalar to a ' 'sparse matrix is not supported') elif isspmatrix(other): if other.shape != self.shape: raise ValueError("inconsistent shapes") return self._add_sparse(other) elif isdense(other): other = broadcast_to(other, self.shape) return self._add_dense(other) else: return NotImplemented
return self.__add__(other)
if isscalarlike(other): if other == 0: return self.copy() raise NotImplementedError('subtracting a nonzero scalar from a ' 'sparse matrix is not supported') elif isspmatrix(other): if other.shape != self.shape: raise ValueError("inconsistent shapes") return self._sub_sparse(other) elif isdense(other): other = broadcast_to(other, self.shape) return self._sub_dense(other) else: return NotImplemented
if isscalarlike(other): if other == 0: return -self.copy() raise NotImplementedError('subtracting a sparse matrix from a ' 'nonzero scalar is not supported') elif isdense(other): other = broadcast_to(other, self.shape) return self._rsub_dense(other) else: return NotImplemented
"""interpret other and call one of the following
self._mul_scalar() self._mul_vector() self._mul_multivector() self._mul_sparse_matrix() """
M, N = self.shape
if other.__class__ is np.ndarray: # Fast path for the most common case if other.shape == (N,): return self._mul_vector(other) elif other.shape == (N, 1): return self._mul_vector(other.ravel()).reshape(M, 1) elif other.ndim == 2 and other.shape[0] == N: return self._mul_multivector(other)
if isscalarlike(other): # scalar value return self._mul_scalar(other)
if issparse(other): if self.shape[1] != other.shape[0]: raise ValueError('dimension mismatch') return self._mul_sparse_matrix(other)
# If it's a list or whatever, treat it like a matrix other_a = np.asanyarray(other)
if other_a.ndim == 0 and other_a.dtype == np.object_: # Not interpretable as an array; return NotImplemented so that # other's __rmul__ can kick in if that's implemented. return NotImplemented
try: other.shape except AttributeError: other = other_a
if other.ndim == 1 or other.ndim == 2 and other.shape[1] == 1: # dense row or column vector if other.shape != (N,) and other.shape != (N, 1): raise ValueError('dimension mismatch')
result = self._mul_vector(np.ravel(other))
if isinstance(other, np.matrix): result = asmatrix(result)
if other.ndim == 2 and other.shape[1] == 1: # If 'other' was an (nx1) column vector, reshape the result result = result.reshape(-1, 1)
return result
elif other.ndim == 2: ## # dense 2D array or matrix ("multivector")
if other.shape[0] != self.shape[1]: raise ValueError('dimension mismatch')
result = self._mul_multivector(np.asarray(other))
if isinstance(other, np.matrix): result = asmatrix(result)
return result
else: raise ValueError('could not interpret dimensions')
# by default, use CSR for __mul__ handlers return self.tocsr()._mul_scalar(other)
return self.tocsr()._mul_vector(other)
return self.tocsr()._mul_multivector(other)
return self.tocsr()._mul_sparse_matrix(other)
if isscalarlike(other): return self.__mul__(other) else: # Don't use asarray unless we have to try: tr = other.transpose() except AttributeError: tr = np.asarray(other).transpose() return (self.transpose() * tr).transpose()
##################################### # matmul (@) operator (Python 3.5+) # #####################################
if isscalarlike(other): raise ValueError("Scalar operands are not allowed, " "use '*' instead") return self.__mul__(other)
if isscalarlike(other): raise ValueError("Scalar operands are not allowed, " "use '*' instead") return self.__rmul__(other)
#################### # Other Arithmetic # ####################
if isscalarlike(other): if rdivide: if true_divide: return np.true_divide(other, self.todense()) else: return np.divide(other, self.todense())
if true_divide and np.can_cast(self.dtype, np.float_): return self.astype(np.float_)._mul_scalar(1./other) else: r = self._mul_scalar(1./other)
scalar_dtype = np.asarray(other).dtype if (np.issubdtype(self.dtype, np.integer) and np.issubdtype(scalar_dtype, np.integer)): return r.astype(self.dtype) else: return r
elif isdense(other): if not rdivide: if true_divide: return np.true_divide(self.todense(), other) else: return np.divide(self.todense(), other) else: if true_divide: return np.true_divide(other, self.todense()) else: return np.divide(other, self.todense()) elif isspmatrix(other): if rdivide: return other._divide(self, true_divide, rdivide=False)
self_csr = self.tocsr() if true_divide and np.can_cast(self.dtype, np.float_): return self_csr.astype(np.float_)._divide_sparse(other) else: return self_csr._divide_sparse(other) else: return NotImplemented
return self._divide(other, true_divide=True)
# Always do true division return self._divide(other, true_divide=True)
# Implementing this as the inverse would be too magical -- bail out return NotImplemented
# Implementing this as the inverse would be too magical -- bail out return NotImplemented
return -self.tocsr()
return NotImplemented
return NotImplemented
return NotImplemented
return self.__itruediv__(other)
return NotImplemented
if self.shape[0] != self.shape[1]: raise TypeError('matrix is not square')
if isintlike(other): other = int(other) if other < 0: raise ValueError('exponent must be >= 0')
if other == 0: from .construct import eye return eye(self.shape[0], dtype=self.dtype) elif other == 1: return self.copy() else: tmp = self.__pow__(other//2) if (other % 2): return self * tmp * tmp else: return tmp * tmp elif isscalarlike(other): raise ValueError('exponent must be an integer') else: return NotImplemented
if attr == 'A': return self.toarray() elif attr == 'T': return self.transpose() elif attr == 'H': return self.getH() elif attr == 'real': return self._real() elif attr == 'imag': return self._imag() elif attr == 'size': return self.getnnz() else: raise AttributeError(attr + " not found")
""" Reverses the dimensions of the sparse matrix.
Parameters ---------- axes : None, optional This argument is in the signature *solely* for NumPy compatibility reasons. Do not pass in anything except for the default value. copy : bool, optional Indicates whether or not attributes of `self` should be copied whenever possible. The degree to which attributes are copied varies depending on the type of sparse matrix being used.
Returns ------- p : `self` with the dimensions reversed.
See Also -------- np.matrix.transpose : NumPy's implementation of 'transpose' for matrices """ return self.tocsr(copy=copy).transpose(axes=axes, copy=False)
"""Element-wise complex conjugation.
If the matrix is of non-complex data type and `copy` is False, this method does nothing and the data is not copied.
Parameters ---------- copy : bool, optional If True, the result is guaranteed to not share data with self.
Returns ------- A : The element-wise complex conjugate.
""" if np.issubdtype(self.dtype, np.complexfloating): return self.tocsr(copy=copy).conj(copy=False) elif copy: return self.copy() else: return self
return self.conj(copy=copy)
# Renamed conjtranspose() -> getH() for compatibility with dense matrices """Return the Hermitian transpose of this matrix.
See Also -------- np.matrix.getH : NumPy's implementation of `getH` for matrices """ return self.transpose().conj()
return self.tocsr()._real()
return self.tocsr()._imag()
"""nonzero indices
Returns a tuple of arrays (row,col) containing the indices of the non-zero elements of the matrix.
Examples -------- >>> from scipy.sparse import csr_matrix >>> A = csr_matrix([[1,2,0],[0,0,3],[4,0,5]]) >>> A.nonzero() (array([0, 0, 1, 2, 2]), array([0, 1, 2, 0, 2]))
"""
# convert to COOrdinate format A = self.tocoo() nz_mask = A.data != 0 return (A.row[nz_mask], A.col[nz_mask])
"""Returns a copy of column j of the matrix, as an (m x 1) sparse matrix (column vector). """ # Spmatrix subclasses should override this method for efficiency. # Post-multiply by a (n x 1) column vector 'a' containing all zeros # except for a_j = 1 from .csc import csc_matrix n = self.shape[1] if j < 0: j += n if j < 0 or j >= n: raise IndexError("index out of bounds") col_selector = csc_matrix(([1], [[j], [0]]), shape=(n, 1), dtype=self.dtype) return self * col_selector
"""Returns a copy of row i of the matrix, as a (1 x n) sparse matrix (row vector). """ # Spmatrix subclasses should override this method for efficiency. # Pre-multiply by a (1 x m) row vector 'a' containing all zeros # except for a_i = 1 from .csr import csr_matrix m = self.shape[0] if i < 0: i += m if i < 0 or i >= m: raise IndexError("index out of bounds") row_selector = csr_matrix(([1], [[0], [i]]), shape=(1, m), dtype=self.dtype) return row_selector * self
# def __array__(self): # return self.toarray()
""" Return a dense matrix representation of this matrix.
Parameters ---------- order : {'C', 'F'}, optional Whether to store multi-dimensional data in C (row-major) or Fortran (column-major) order in memory. The default is 'None', indicating the NumPy default of C-ordered. Cannot be specified in conjunction with the `out` argument.
out : ndarray, 2-dimensional, optional If specified, uses this array (or `numpy.matrix`) as the output buffer instead of allocating a new array to return. The provided array must have the same shape and dtype as the sparse matrix on which you are calling the method.
Returns ------- arr : numpy.matrix, 2-dimensional A NumPy matrix object with the same shape and containing the same data represented by the sparse matrix, with the requested memory order. If `out` was passed and was an array (rather than a `numpy.matrix`), it will be filled with the appropriate values and returned wrapped in a `numpy.matrix` object that shares the same memory. """ return asmatrix(self.toarray(order=order, out=out))
""" Return a dense ndarray representation of this matrix.
Parameters ---------- order : {'C', 'F'}, optional Whether to store multi-dimensional data in C (row-major) or Fortran (column-major) order in memory. The default is 'None', indicating the NumPy default of C-ordered. Cannot be specified in conjunction with the `out` argument.
out : ndarray, 2-dimensional, optional If specified, uses this array as the output buffer instead of allocating a new array to return. The provided array must have the same shape and dtype as the sparse matrix on which you are calling the method. For most sparse types, `out` is required to be memory contiguous (either C or Fortran ordered).
Returns ------- arr : ndarray, 2-dimensional An array with the same shape and containing the same data represented by the sparse matrix, with the requested memory order. If `out` was passed, the same object is returned after being modified in-place to contain the appropriate values. """ return self.tocoo(copy=False).toarray(order=order, out=out)
# Any sparse matrix format deriving from spmatrix must define one of # tocsr or tocoo. The other conversion methods may be implemented for # efficiency, but are not required. """Convert this matrix to Compressed Sparse Row format.
With copy=False, the data/indices may be shared between this matrix and the resultant csr_matrix. """ return self.tocoo(copy=copy).tocsr(copy=False)
"""Convert this matrix to Dictionary Of Keys format.
With copy=False, the data/indices may be shared between this matrix and the resultant dok_matrix. """ return self.tocoo(copy=copy).todok(copy=False)
"""Convert this matrix to COOrdinate format.
With copy=False, the data/indices may be shared between this matrix and the resultant coo_matrix. """ return self.tocsr(copy=False).tocoo(copy=copy)
"""Convert this matrix to LInked List format.
With copy=False, the data/indices may be shared between this matrix and the resultant lil_matrix. """ return self.tocsr(copy=False).tolil(copy=copy)
"""Convert this matrix to sparse DIAgonal format.
With copy=False, the data/indices may be shared between this matrix and the resultant dia_matrix. """ return self.tocoo(copy=copy).todia(copy=False)
"""Convert this matrix to Block Sparse Row format.
With copy=False, the data/indices may be shared between this matrix and the resultant bsr_matrix.
When blocksize=(R, C) is provided, it will be used for construction of the bsr_matrix. """ return self.tocsr(copy=False).tobsr(blocksize=blocksize, copy=copy)
"""Convert this matrix to Compressed Sparse Column format.
With copy=False, the data/indices may be shared between this matrix and the resultant csc_matrix. """ return self.tocsr(copy=copy).tocsc(copy=False)
"""Returns a copy of this matrix.
No data/indices will be shared between the returned value and current matrix. """ return self.__class__(self, copy=True)
""" Sum the matrix elements over a given axis.
Parameters ---------- axis : {-2, -1, 0, 1, None} optional Axis along which the sum is computed. The default is to compute the sum of all the matrix elements, returning a scalar (i.e. `axis` = `None`). dtype : dtype, optional The type of the returned matrix and of the accumulator in which the elements are summed. The dtype of `a` is used by default unless `a` has an integer dtype of less precision than the default platform integer. In that case, if `a` is signed then the platform integer is used while if `a` is unsigned then an unsigned integer of the same precision as the platform integer is used.
.. versionadded:: 0.18.0
out : np.matrix, optional Alternative output matrix in which to place the result. It must have the same shape as the expected output, but the type of the output values will be cast if necessary.
.. versionadded:: 0.18.0
Returns ------- sum_along_axis : np.matrix A matrix with the same shape as `self`, with the specified axis removed.
See Also -------- np.matrix.sum : NumPy's implementation of 'sum' for matrices
""" validateaxis(axis)
# We use multiplication by a matrix of ones to achieve this. # For some sparse matrix formats more efficient methods are # possible -- these should override this function. m, n = self.shape
# Mimic numpy's casting. res_dtype = get_sum_dtype(self.dtype)
if axis is None: # sum over rows and columns return (self * asmatrix(np.ones( (n, 1), dtype=res_dtype))).sum( dtype=dtype, out=out)
if axis < 0: axis += 2
# axis = 0 or 1 now if axis == 0: # sum over columns ret = asmatrix(np.ones( (1, m), dtype=res_dtype)) * self else: # sum over rows ret = self * asmatrix( np.ones((n, 1), dtype=res_dtype))
if out is not None and out.shape != ret.shape: raise ValueError("dimensions do not match")
return ret.sum(axis=(), dtype=dtype, out=out)
""" Compute the arithmetic mean along the specified axis.
Returns the average of the matrix elements. The average is taken over all elements in the matrix by default, otherwise over the specified axis. `float64` intermediate and return values are used for integer inputs.
Parameters ---------- axis : {-2, -1, 0, 1, None} optional Axis along which the mean is computed. The default is to compute the mean of all elements in the matrix (i.e. `axis` = `None`). dtype : data-type, optional Type to use in computing the mean. For integer inputs, the default is `float64`; for floating point inputs, it is the same as the input dtype.
.. versionadded:: 0.18.0
out : np.matrix, optional Alternative output matrix in which to place the result. It must have the same shape as the expected output, but the type of the output values will be cast if necessary.
.. versionadded:: 0.18.0
Returns ------- m : np.matrix
See Also -------- np.matrix.mean : NumPy's implementation of 'mean' for matrices
""" def _is_integral(dtype): return (np.issubdtype(dtype, np.integer) or np.issubdtype(dtype, np.bool_))
validateaxis(axis)
res_dtype = self.dtype.type integral = _is_integral(self.dtype)
# output dtype if dtype is None: if integral: res_dtype = np.float64 else: res_dtype = np.dtype(dtype).type
# intermediate dtype for summation inter_dtype = np.float64 if integral else res_dtype inter_self = self.astype(inter_dtype)
if axis is None: return (inter_self / np.array( self.shape[0] * self.shape[1]))\ .sum(dtype=res_dtype, out=out)
if axis < 0: axis += 2
# axis = 0 or 1 now if axis == 0: return (inter_self * (1.0 / self.shape[0])).sum( axis=0, dtype=res_dtype, out=out) else: return (inter_self * (1.0 / self.shape[1])).sum( axis=1, dtype=res_dtype, out=out)
"""Returns the k-th diagonal of the matrix.
Parameters ---------- k : int, optional Which diagonal to set, corresponding to elements a[i, i+k]. Default: 0 (the main diagonal).
.. versionadded:: 1.0
See also -------- numpy.diagonal : Equivalent numpy function.
Examples -------- >>> from scipy.sparse import csr_matrix >>> A = csr_matrix([[1, 2, 0], [0, 0, 3], [4, 0, 5]]) >>> A.diagonal() array([1, 0, 5]) >>> A.diagonal(k=1) array([2, 3]) """ return self.tocsr().diagonal(k=k)
""" Set diagonal or off-diagonal elements of the array.
Parameters ---------- values : array_like New values of the diagonal elements.
Values may have any length. If the diagonal is longer than values, then the remaining diagonal entries will not be set. If values if longer than the diagonal, then the remaining values are ignored.
If a scalar value is given, all of the diagonal is set to it.
k : int, optional Which off-diagonal to set, corresponding to elements a[i,i+k]. Default: 0 (the main diagonal).
""" M, N = self.shape if (k > 0 and k >= N) or (k < 0 and -k >= M): raise ValueError("k exceeds matrix dimensions") self._setdiag(np.asarray(values), k)
M, N = self.shape if k < 0: if values.ndim == 0: # broadcast max_index = min(M+k, N) for i in xrange(max_index): self[i - k, i] = values else: max_index = min(M+k, N, len(values)) if max_index <= 0: return for i, v in enumerate(values[:max_index]): self[i - k, i] = v else: if values.ndim == 0: # broadcast max_index = min(M, N-k) for i in xrange(max_index): self[i, i + k] = values else: max_index = min(M, N-k, len(values)) if max_index <= 0: return for i, v in enumerate(values[:max_index]): self[i, i + k] = v
if out is not None: if order is not None: raise ValueError('order cannot be specified if out ' 'is not None') if out.shape != self.shape or out.dtype != self.dtype: raise ValueError('out array must be same dtype and shape as ' 'sparse matrix') out[...] = 0. return out else: return np.zeros(self.shape, dtype=self.dtype, order=order)
"""Is x of a sparse matrix type?
Parameters ---------- x object to check for being a sparse matrix
Returns ------- bool True if x is a sparse matrix, False otherwise
Notes ----- issparse and isspmatrix are aliases for the same function.
Examples -------- >>> from scipy.sparse import csr_matrix, isspmatrix >>> isspmatrix(csr_matrix([[5]])) True
>>> from scipy.sparse import isspmatrix >>> isspmatrix(5) False """
|