brainpy.math.sparse: Sparse Operators

csrmv	Product of CSR sparse matrix and a dense vector using cuSPARSE algorithm.
seg_matmul	Sparse matrix multiplication.
csr_to_dense
csr_to_coo	Given CSR (indices, indptr) return COO (row, col)
coo_to_csr	convert pre_ids, post_ids to (indices, indptr).