numpy.bmat#

numpy.bmat(obj, ldict=None, gdict=None)[source]#

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

Parameters:

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

Returns:

outmatrix: 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

>>> import numpy as np
>>> A = np.asmatrix('1 1; 1 1')
>>> B = np.asmatrix('2 2; 2 2')
>>> C = np.asmatrix('3 4; 5 6')
>>> D = np.asmatrix('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]])