Error: float() argument must be a string or a number, not 'ArrayBox'

[kaipengliuHIT]

When I run ：
import autograd.numpy as npa
a = npa.ones((7,7))
b = 2 * npa.ones((3,3))
a[2:5, 3:6] = b.flatten().reshape((3,3))
def objective(b):
a[2:5, 3:6] = b.flatten().reshape((3,3))
acs = sum(rhoxy)
return acs
objective_jac = jacobian(objective, mode='reverse')
aa = objective_jac(b)

I will get this error:

---

TypeError Traceback (most recent call last)
TypeError: float() argument must be a string or a number, not 'ArrayBox'

The above exception was the direct cause of the following exception:

ValueError Traceback (most recent call last)
in
8 return acs
9 objective_jac = jacobian(objective, mode='reverse')
---> 10 aa = objective_jac(b)

D:\Anaconda3\envs\ceviche\lib\site-packages\autograd-1.3-py3.7.egg\autograd\wrap_util.py in nary_f(*args, **kwargs)
18 else:
19 x = tuple(args[i] for i in argnum)
---> 20 return unary_operator(unary_f, x, *nary_op_args, **nary_op_kwargs)
21 return nary_f
22 return nary_operator

D:\CEVICHE\ceviche\jacobians.py in jacobian_reverse(fun, x)
30 def jacobian_reverse(fun, x):
31 """ Compute jacobian of fun with respect to x using reverse mode differentiation"""
---> 32 vjp, ans = make_vjp(fun, x)
33 grads = map(vjp, vspace(ans).standard_basis())
34 m, n = _jac_shape(x, ans)

D:\Anaconda3\envs\ceviche\lib\site-packages\autograd-1.3-py3.7.egg\autograd\core.py in make_vjp(fun, x)
8 def make_vjp(fun, x):
9 start_node = VJPNode.new_root()
---> 10 end_value, end_node = trace(start_node, fun, x)
11 if end_node is None:
12 def vjp(g): return vspace(x).zeros()

D:\Anaconda3\envs\ceviche\lib\site-packages\autograd-1.3-py3.7.egg\autograd\tracer.py in trace(start_node, fun, x)
8 with trace_stack.new_trace() as t:
9 start_box = new_box(x, t, start_node)
---> 10 end_box = fun(start_box)
11 if isbox(end_box) and end_box._trace == start_box._trace:
12 return end_box._value, end_box._node

D:\Anaconda3\envs\ceviche\lib\site-packages\autograd-1.3-py3.7.egg\autograd\wrap_util.py in unary_f(x)
13 else:
14 subargs = subvals(args, zip(argnum, x))
---> 15 return fun(*subargs, **kwargs)
16 if isinstance(argnum, int):
17 x = args[argnum]

in objective(b)
4 a[2:5, 3:6] = b.flatten().reshape((3,3))
5 def objective(b):
----> 6 a[2:5, 3:6] = b.flatten().reshape((3,3))
7 acs = sum(rhoxy)
8 return acs

ValueError: setting an array element with a sequence.