scipy.sparse.

vstack#

scipy.sparse.vstack(blocks, format=None, dtype=None)[source]#

Stack sparse arrays vertically (row wise)

Parameters:

blocks: sequence of sparse arrays with compatible shapes
formatstr, optional: sparse format of the result (e.g., “csr”) by default an appropriate sparse array format is returned. This choice is subject to change.
dtypedtype, optional: The data-type of the output array. If not given, the dtype is determined from that of blocks.

Returns:

new_arraysparse matrix or array

If any block in blocks is a sparse array, return a sparse array. Otherwise return a sparse matrix.

If you want a sparse array built from blocks that are not sparse arrays, use block(vstack(blocks)) or convert one block e.g. blocks[0] = csr_array(blocks[0]).

See also

hstack: stack sparse matrices horizontally (column wise)

Examples

>>> from scipy.sparse import coo_array, vstack
>>> A = coo_array([[1, 2], [3, 4]])
>>> B = coo_array([[5, 6]])
>>> vstack([A, B]).toarray()
array([[1, 2],
       [3, 4],
       [5, 6]])