numpy.matrixlib.defmatrix

module documentation

Undocumented

Class matrix matrix(data, dtype=None, copy=True)
Function ​_convert​_from​_string Undocumented
Function ​_from​_string Undocumented
Function asmatrix Interpret the input as a matrix.
Function bmat Build a matrix object from a string, nested sequence, or array.
def _convert_from_string(data):

Undocumented

def _from_string(str, gdict, ldict):

Undocumented

@set_module('numpy')
def asmatrix(data, dtype=None):

Interpret the input as a matrix.

Unlike matrix, asmatrix does not make a copy if the input is already a matrix or an ndarray. Equivalent to matrix(data, copy=False).

Parameters

data : array_like
Input data.
dtype : data-type
Data-type of the output matrix.

Returns

mat : matrix
data interpreted as a matrix.

Examples

>>> x = np.array([[1, 2], [3, 4]])
>>> m = np.asmatrix(x)
>>> x[0,0] = 5
>>> m
matrix([[5, 2],
        [3, 4]])
@set_module('numpy')
def bmat(obj, ldict=None, gdict=None):

Build a matrix object from a string, nested sequence, or array.

Parameters

obj : str or array_like
Input data. If a string, variables in the current scope may be referenced by name.
ldict : dict, optional
A dictionary that replaces local operands in current frame. Ignored if obj is not a string or gdict is None.
gdict : dict, optional
A dictionary that replaces global operands in current frame. Ignored if obj is not a string.

Returns

out : matrix
Returns a matrix object, which is a specialized 2-D array.

See Also

block :
A generalization of this function for N-d arrays, that returns normal ndarrays.

Examples

>>> A = np.mat('1 1; 1 1')
>>> B = np.mat('2 2; 2 2')
>>> C = np.mat('3 4; 5 6')
>>> D = np.mat('7 8; 9 0')

All the following expressions construct the same block matrix:

>>> np.bmat([[A, B], [C, D]])
matrix([[1, 1, 2, 2],
        [1, 1, 2, 2],
        [3, 4, 7, 8],
        [5, 6, 9, 0]])
>>> np.bmat(np.r_[np.c_[A, B], np.c_[C, D]])
matrix([[1, 1, 2, 2],
        [1, 1, 2, 2],
        [3, 4, 7, 8],
        [5, 6, 9, 0]])
>>> np.bmat('A,B; C,D')
matrix([[1, 1, 2, 2],
        [1, 1, 2, 2],
        [3, 4, 7, 8],
        [5, 6, 9, 0]])