def extract_sparse(sparse_mat):
    """
    Extract a coordinate levele representation as a tuple for a PyTorch
    sparse tensor.
    
    Args:
    - sparse_mat (PyTorch sparse tensor) - The sparse matrix from which to
        extract coordinates and values.
        
    Returns:
    - A tuple of the indices (coordinates) of non-zero values and a
        vector of the corresponding values.
    """
    # Perform extraction
    indices = sparse_mat._indices().t().numpy()
    values = sparse_mat._values().numpy()
    
    # Return tuple
    return (indices, values)