def synthesis_mat(a, b):
""" gives conbination of two matrix a and b
Parameters
----------
a, b : scipy.sparse.occ_matrix
a and b must be square matrix and
Returns
-------
out : scipy.sparse.occ_matrix
"""
(na_row, na_col) = a.shape
(nb_row, nb_col) = b.shape
n_row = na_row * nb_row
n_col = na_col * nb_col
num = len(a.data)*len(b.data)
ncol = na_col*b.col
col = bspline_bind.outer_sum(ncol, a.col)
nrow = na_row*b.row
row = outer_sum(nrow, a.row)
data = np.reshape(np.outer(b.data, a.data), (num))
return coo_matrix((data, (row, col)), shape=(n_row, n_col))
def outer_sum(a, b):
""" gives summation version of outer product
{a_i+b_j}_{i, j}
Parameters
----------
a, b : 1D numpay.array
Results
-------
out : 1D numarray.array
"""
return bspline_bind.outer_sum(a, b)
