There is an HHL example in IBM Qiskit
If I run on that website (click "Try") in Section 4 and set
time=np.pi*3/4, I get 100% fidelity as expected. However, if I copy those code and run it on my server or in the IBM Q account, it is no longer 100%.
I also try with my other matrix which I expect to have an exact solution. Again, I get 100% fidelity if I modify the code in that website but I get only 80% if I run on my server. The matrix I am trying is
[[1 -0.5],[-0.5, 1]] which has an exact solution if
Do you know why? Are they calling different functions? How do I solve this problem?
I also want to learn how they calculate fidelity. Do you know where I can find the details of