def csr2coo(x, data, indices):
"""Converts a CSR-matrix to COO format.
Args:
x (cupyx.scipy.sparse.csr_matrix): A matrix to be converted.
data (cupy.ndarray): A data array for converted data.
indices (cupy.ndarray): An index array for converted data.
Returns:
cupyx.scipy.sparse.coo_matrix: A converted matrix.
"""
if not check_availability('csr2coo'):
raise RuntimeError('csr2coo is not available.')
handle = device.get_cusparse_handle()
m = x.shape[0]
nnz = len(x.data)
row = cupy.empty(nnz, 'i')
cusparse.xcsr2coo(
handle, x.indptr.data.ptr, nnz, m, row.data.ptr,
cusparse.CUSPARSE_INDEX_BASE_ZERO)
# data and indices did not need to be copied already
return cupyx.scipy.sparse.coo_matrix(
(data, (row, indices)), shape=x.shape)
def csc2coo(x, data, indices):
"""Converts a CSC-matrix to COO format.
Args:
x (cupyx.scipy.sparse.csc_matrix): A matrix to be converted.
data (cupy.ndarray): A data array for converted data.
indices (cupy.ndarray): An index array for converted data.
Returns:
cupyx.scipy.sparse.coo_matrix: A converted matrix.
"""
handle = device.get_cusparse_handle()
n = x.shape[1]
nnz = len(x.data)
col = cupy.empty(nnz, 'i')
cusparse.xcsr2coo(handle, x.indptr.data.ptr, nnz, n, col.data.ptr,
cusparse.CUSPARSE_INDEX_BASE_ZERO)
# data and indices did not need to be copied already
return cupyx.scipy.sparse.coo_matrix((data, (indices, col)), shape=x.shape)
