I want to compare the theoretical output of a circuit measurement with the actual output from a real quantum computer. I can approximate the ideal output by running the circuit on a simulator. However when you're measuring a state in superposition, the results you get from a simulator are still nondeterministic, making them not ideal for comparison.
For instance, when measuring a single qubit in even superposition (the state $\frac{1}{\sqrt{2}}(|0\rangle + |1\rangle)$, the ideal result would be that you measure $|0\rangle$ with probability $0.5$ and $|1\rangle$ with probability $0.5$. However, when running on a simulator, you might naturally get $|0\rangle$ with probability $0.501$ and $|1\rangle$ with probability $0.499$:
In other words, knowing that the theoretical probability of obtaining state $|\phi\rangle$ when measuring a state $|\psi\rangle$ is $\langle\phi|\psi\rangle$, is there a function in Qiskit to calculate this value from a circuit or state, or to get the ideal probability distribution that I can compare my actual distribution against?