def test_QobjHerm():
"Qobj Hermicity"
N = 10
data = np.random.random(
(N, N)) + 1j * np.random.random((N, N)) - (0.5 + 0.5j)
q = Qobj(data)
assert_equal(q.isherm, False)
data = data + data.conj().T
q = Qobj(data)
assert_(q.isherm)
q_a = destroy(5)
assert_(not q_a.isherm)
q_ad = create(5)
assert_(not q_ad.isherm)
# test addition of two nonhermitian operators adding up to a hermitian one
q_x = q_a + q_ad
assert_(q_x.isherm) # isherm use the _isherm cache from q_a + q_ad
q_x._isherm = None # reset _isherm cache
assert_(q_x.isherm) # recalculate _isherm
# test addition of one hermitan and one nonhermitian operator
q = q_x + q_a
assert_(not q.isherm)
q._isherm = None
assert_(not q.isherm)
# test addition of two hermitan operators
q = q_x + q_x
assert_(q.isherm)
q._isherm = None
assert_(q.isherm)
def test_QobjHerm():
"Qobj Hermicity"
N = 10
data = np.random.random((N, N)) + 1j * np.random.random(
(N, N)) - (0.5 + 0.5j)
q = Qobj(data)
assert_equal(q.isherm, False)
data = data + data.conj().T
q = Qobj(data)
assert_(q.isherm)
q_a = destroy(5)
assert_(not q_a.isherm)
q_ad = create(5)
assert_(not q_ad.isherm)
# test addition of two nonhermitian operators adding up to a hermitian one
q_x = q_a + q_ad
assert_(q_x.isherm) # isherm use the _isherm cache from q_a + q_ad
q_x._isherm = None # reset _isherm cache
assert_(q_x.isherm) # recalculate _isherm
# test addition of one hermitan and one nonhermitian operator
q = q_x + q_a
assert_(not q.isherm)
q._isherm = None
assert_(not q.isherm)
# test addition of two hermitan operators
q = q_x + q_x
assert_(q.isherm)
q._isherm = None
assert_(q.isherm)
def tensor(*args):
"""Calculates the tensor product of input operators.
Parameters
----------
args : array_like
``list`` or ``array`` of quantum objects for tensor product.
Returns
-------
obj : qobj
A composite quantum object.
Examples
--------
>>> tensor([sigmax(), sigmax()]) # doctest: +SKIP
Quantum object: dims = [[2, 2], [2, 2]], \
shape = [4, 4], type = oper, isHerm = True
Qobj data =
[[ 0.+0.j 0.+0.j 0.+0.j 1.+0.j]
[ 0.+0.j 0.+0.j 1.+0.j 0.+0.j]
[ 0.+0.j 1.+0.j 0.+0.j 0.+0.j]
[ 1.+0.j 0.+0.j 0.+0.j 0.+0.j]]
"""
if not args:
raise TypeError("Requires at least one input argument")
if len(args) == 1 and isinstance(args[0], (list, np.ndarray)):
# this is the case when tensor is called on the form:
# tensor([q1, q2, q3, ...])
qlist = args[0]
elif len(args) == 1 and isinstance(args[0], Qobj):
# tensor is called with a single Qobj as an argument, do nothing
return args[0]
else:
# this is the case when tensor is called on the form:
# tensor(q1, q2, q3, ...)
qlist = args
if not all([isinstance(q, Qobj) for q in qlist]):
# raise error if one of the inputs is not a quantum object
raise TypeError("One of inputs is not a quantum object")
out = Qobj()
if qlist[0].issuper:
out.superrep = qlist[0].superrep
if not all([q.superrep == out.superrep for q in qlist]):
raise TypeError("In tensor products of superroperators, all must" +
"have the same representation")
out.isherm = True
for n, q in enumerate(qlist):
if n == 0:
out.data = q.data
out.dims = q.dims
else:
out.data = zcsr_kron(out.data, q.data)
out.dims = [out.dims[0] + q.dims[0], out.dims[1] + q.dims[1]]
out.isherm = out.isherm and q.isherm
if not out.isherm:
out._isherm = None
return out.tidyup() if qutip.settings.auto_tidyup else out
def tensor(*args):
"""Calculates the tensor product of input operators.
Parameters
----------
args : array_like
``list`` or ``array`` of quantum objects for tensor product.
Returns
-------
obj : qobj
A composite quantum object.
Examples
--------
>>> tensor([sigmax(), sigmax()])
Quantum object: dims = [[2, 2], [2, 2]], \
shape = [4, 4], type = oper, isHerm = True
Qobj data =
[[ 0.+0.j 0.+0.j 0.+0.j 1.+0.j]
[ 0.+0.j 0.+0.j 1.+0.j 0.+0.j]
[ 0.+0.j 1.+0.j 0.+0.j 0.+0.j]
[ 1.+0.j 0.+0.j 0.+0.j 0.+0.j]]
"""
if not args:
raise TypeError("Requires at least one input argument")
if len(args) == 1 and isinstance(args[0], (list, np.ndarray)):
# this is the case when tensor is called on the form:
# tensor([q1, q2, q3, ...])
qlist = args[0]
elif len(args) == 1 and isinstance(args[0], Qobj):
# tensor is called with a single Qobj as an argument, do nothing
return args[0]
else:
# this is the case when tensor is called on the form:
# tensor(q1, q2, q3, ...)
qlist = args
if not all([isinstance(q, Qobj) for q in qlist]):
# raise error if one of the inputs is not a quantum object
raise TypeError("One of inputs is not a quantum object")
out = Qobj()
if qlist[0].issuper:
out.superrep = qlist[0].superrep
if not all([q.superrep == out.superrep for q in qlist]):
raise TypeError("In tensor products of superroperators, all must" +
"have the same representation")
out.isherm = True
for n, q in enumerate(qlist):
if n == 0:
out.data = q.data
out.dims = q.dims
else:
out.data = sp.kron(out.data, q.data, format='csr')
out.dims = [out.dims[0] + q.dims[0], out.dims[1] + q.dims[1]]
out.isherm = out.isherm and q.isherm
if not out.isherm:
out._isherm = None
return out.tidyup() if qutip.settings.auto_tidyup else out
