def printPCGstatus(info):
    """
    Function that takes the status result of the scipy.sparse.linalg.bicgstab
    algorithm and print it in an understandable way.
    """
    if info == 0:
        print('successful exit!')
    elif info > 0:
        print('convergence to tolerance not achieved')
        print('number of iterations: ' + str(info))
    elif info < 0:
        print('illegal input or breakdown.')
