initial_state parameter yields an error

[mdecandia]

When submitting a problem that specifies an initial_state, the inspector fails to start up as the below error is thrown:

ERROR    dwave.inspector.server:app.py:1891 Exception on /api/problems/d6684f12-cc17-4ba3-a4bf-74c3e2dc31db [GET]
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/flask/app.py", line 2446, in wsgi_app
    response = self.full_dispatch_request()
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/flask/app.py", line 1952, in full_dispatch_request
    return self.finalize_request(rv)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/flask/app.py", line 1967, in finalize_request
    response = self.make_response(rv)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/flask/app.py", line 2111, in make_response
    rv = jsonify(rv)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/flask/json/__init__.py", line 370, in jsonify
    dumps(data, indent=indent, separators=separators) + "\n",
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/flask/json/__init__.py", line 211, in dumps
    rv = _json.dumps(obj, **kwargs)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/__init__.py", line 238, in dumps
    **kw).encode(obj)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/encoder.py", line 199, in encode
    chunks = self.iterencode(o, _one_shot=True)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/encoder.py", line 257, in iterencode
    return _iterencode(o, 0)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/flask/json/__init__.py", line 100, in default
    return _json.JSONEncoder.default(self, o)
  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/json/encoder.py", line 179, in default
    raise TypeError(f'Object of type {o.__class__.__name__} '
TypeError: Object of type int8 is not JSON serializable

The browser window shows a blue screen with Error: Unexpected token < in JSON at position 0
Example problem:

        h = {}
        J = {(0, 4): 1}

        # get solver properties
        anneal_offset_ranges = solver.properties['anneal_offset_ranges']
        num_qubits = solver.properties['num_qubits']
        anneal_offset = [0] * num_qubits

        for i in solver.nodes:
            anneal_offset[i] = anneal_offset_ranges[i][0]

        forward_answer = solver.sample_ising(h, J, annealing_time=25)
        i5 = int(5.0 / 95 * len(forward_answer.samples))
        initial = dict(zip(forward_answer.variables, forward_answer.sampleset._record[i5].sample))

        params = {
            "anneal_offsets": anneal_offset,
            "anneal_schedule": [[0.0, 1.0], [10.0, 1.0]],
            "h_gain_schedule": [[0.0, 1.0], [10.0, 1.0]],
            "initial_state": initial,
            "reinitialize_state": True
        }

        # sample
        response = solver.sample_ising(h, J, **params)

        # inspect
        dwave.inspector.show((h, J), response)

[randomir]

The problem here is not with the initial_state per se, it's that numpy.ndarray is not JSON serializable by default -- and you're using it for (some) params.

A general fix will be with #81.

[randomir]

Fixed with #135.