fixed wrong time value in Trotterized Unitary #8126 #9388
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BramDo
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manoelmarques,
woodsp-ibm and
ikkoham
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Changelog: Bugfix
| ti = Parameter("t") | ||
| u2 = Suzuki(1, order=1).convert(ti * ham) | ||
| u2_t = u2.bind_parameters({ti: time}) | ||
| self.assertEqual(u2_t, u1) |
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In addition to asserting the operators are equal, add an assertion that explicitly ensures that the coefficient is 11 and not 121.
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I will add the expliceit assertion.
| @@ -60,6 +60,8 @@ def convert(self, operator: OperatorBase) -> OperatorBase: | |||
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| if isinstance(operator.coeff, (float, ParameterExpression)): | |||
| coeff = operator.coeff | |||
| if not isinstance(coeff, float): | |||
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A positive condition is clearer than a negative condition:
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I got a DeprecationWarning: The class qiskit.opflow.evolutions.trotterizations.suzuki.Suzuki is deprecatied as of qiskit-terra 0.24.0. I propose to add this condition in the Suzuki class in opflow, however this will only be a temporary aprovement because the opflow class is deprecated. In thw future PauliEvolutionGate could be used.
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With the removal of opflow in #11111, this PR is now obsolete. Thanks for the effort at the time, and sorry we weren't able to move it merge before opflow was removed. |
Summary
fixes #8126
Details and comments
Fix wrong time value in Trotterized unitary #8126.
When Computing a suzuki decomposition of a Hamiltonian for a given time t, if t is a float, everything works fine.
If t is a Parameter object the value gets squared when it is bound.
This is tested with function test_suzuki_trotterization_time_parameter(self).