def _first_and_last_element ( arr ) : if isinstance ( arr , np . ndarray ) or hasattr ( arr , 'data' ) : # numpy array or sparse matrix with .data attribute data = arr . data if sparse . issparse ( arr ) else arr return data . flat [ 0 ] , data . flat [ - 1 ] else : # Sparse matrices without .data attribute. Only dok_matrix at # the time of writing, in this case indexing is fast return arr [ 0 , 0 ] , arr [ - 1 , - 1 ]
how to access a specific element of a sparse matrix python3
Returns first and last element of numpy array or sparse matrix .
def _first_and_last_element(arr):
    """Returns first and last element of numpy array or sparse matrix."""
    if isinstance(arr, np.ndarray) or hasattr(arr, 'data'):
        # numpy array or sparse matrix with .data attribute
        data = arr.data if sparse.issparse(arr) else arr
        return data.flat[0], data.flat[-1]
    else:
        # Sparse matrices without .data attribute. Only dok_matrix at
        # the time of writing, in this case indexing is fast
        return arr[0, 0], arr[-1, -1]