def dot(self, o) -> "CscMat":
"""
Dot product
:param o: CscMat instance
:return: CscMat instance
"""
# 2-pass matrix multiplication
Cp = np.empty(self.n + 1, dtype=np.int32)
sptools.csc_matmat_pass1(self.n, o.m, self.indptr, self.indices,
o.indptr, o.indices, Cp)
nnz = Cp[-1]
Ci = np.empty(nnz, dtype=np.int32)
Cx = np.empty(nnz, dtype=np.float64)
sptools.csc_matmat_pass2(self.n, o.m, self.indptr, self.indices,
self.data, o.indptr, o.indices, o.data, Cp,
Ci, Cx)
return CscMat((Cx, Ci, Cp), shape=self.shape)
def csc_dot2(A: csc_matrix, B: csc_matrix):
"""
:param A:
:param B:
:return:
"""
Cp = np.empty(A.shape[0] + 1, dtype=np.int32)
sptools.csc_matmat_pass1(A.shape[0], B.shape[1], A.indptr, A.indices,
B.indptr, B.indices, Cp)
nnz = Cp[-1]
Ci = np.empty(nnz, dtype=np.int32)
Cx = np.empty(nnz, dtype=np.float64)
sptools.csc_matmat_pass2(A.shape[0], B.shape[1], A.indptr, A.indices,
A.data, B.indptr, B.indices, B.data, Cp, Ci, Cx)
N, M = A.shape[0], B.shape[1]
C = csc_matrix((Cx, Ci, Cp), shape=(N, M))
return C
def __mul__(self, other):
"""
Matrix multiplication
:param other: CscMat instance
:return: CscMat instance
"""
if isinstance(other, CscMat): # mat-mat multiplication
# 2-pass matrix multiplication
Cp = np.empty(self.n + 1, dtype=np.int32)
sptools.csc_matmat_pass1(self.n, other.m, self.indptr,
self.indices, other.indptr, other.indices,
Cp)
nnz = Cp[-1]
Ci = np.empty(nnz, dtype=np.int32)
Cx = np.empty(nnz, dtype=np.float64)
sptools.csc_matmat_pass2(self.n, other.m, self.indptr,
self.indices, self.data, other.indptr,
other.indices, other.data, Cp, Ci, Cx)
return CscMat(n=self.m, m=other.m, indptr=Cp, indices=Ci, data=Cx)
elif isinstance(
other, np.ndarray): # multiply by a vector or array of vectors
if len(other.shape) == 1:
y = np.zeros(self.m, dtype=np.float64)
sptools.csc_matvec(self.m, self.n, self.indptr, self.indices,
self.data, other, y)
return y
elif len(other.shape) == 2:
'''
* Input Arguments:
* I n_row - number of rows in A
* I n_col - number of columns in A
* I n_vecs - number of column vectors in X and Y
* I Ap[n_row+1] - row pointer
* I Aj[nnz(A)] - column indices
* T Ax[nnz(A)] - nonzeros
* T Xx[n_col,n_vecs] - input vector
*
* Output Arguments:
* T Yx[n_row,n_vecs] - output vector
*
* Note:
* Output array Yx must be preallocated
*
void csc_matvecs(const I n_row,
const I n_col,
const I n_vecs,
const I Ap[],
const I Ai[],
const T Ax[],
const T Xx[],
T Yx[])
'''
n_col, n_vecs = other.shape
y = np.zeros((self.m, n_vecs), dtype=np.float64)
sptools.csc_matvecs(self.m, self.n, n_vecs, self.indptr,
self.indices, self.data, other, y)
return y
elif isinstance(other, float) or isinstance(
other, int): # multiply by a scalar value
C = self.copy()
C.data *= other
return C
else:
raise Exception('Type not supported')