def axpy(x, y, a=1.0):
    """Quick level-1 call to BLAS y = a*x+y.

    Parameters
    ----------
    x : array_like
        nx1 real or complex vector
    y : array_like
        nx1 real or complex vector
    a : float
        real or complex scalar

    Returns
    -------
    y : array_like
        Input variable y is rewritten

    Notes
    -----
    The call to get_blas_funcs automatically determines the prefix for the blas
    call.

    """
    from scipy.linalg import get_blas_funcs
    fn = get_blas_funcs(['axpy'], [x, y])[0]
    fn(x, y, a)
