human
Here's a good function header given the following:
I wrote the below code

    (m, n) = Jop.shape
    def matvec(x):
        x_free = x.ravel().copy()
        x_free[active_set] = 0
        return Jop.matvec((x * d))
    def rmatvec(x):
        r = (d * Jop.rmatvec(x))
        r[active_set] = 0
        return r
    return LinearOperator((m, n), matvec=matvec, rmatvec=rmatvec, dtype=float)

What's a good function header?
assistant
#Here's a good function header.

def lsmr_operator(Jop, d, active_set):