Recently, I was doing research on QML. Qiskit gave detailed steps on how to encode data into quantum states, but I was confused about one point: there are different feature mapping methods under qiskit.circuit.library, such as : ZZFeatureMap, PauliFeatureMap, etc. I would like to ask if they have different applicability to different structured data?
Are they a general way of feature mapping?
For the study of regression datasets, which one is the best featuremap method?