Fix MeasureMulti*PauliSum

[yannick-couzinie]

Not sure whether I am misunderstanding the function.

self.measure_multiple_times returns a [len(obs_list), num_wires] tensor, you have to take the product over the wires first to get the measurement of the Pauli string and then sum over the obs_list (multiplied by coefficients in the case of MeasureMultiQubitPaulisum.

[yannick-couzinie]

I don't think NumPy 2 has the "complex_" datatype any more . This last commit, strictly speaking, has nothing to do with MeasureMultiPauliSum, but should get the workflows to run. I have run the workflow

       python3 examples/qubit_rotation/qubit_rotation.py --epochs 1
        python3 examples/vqe/vqe.py --epochs 1 --steps_per_epoch 1
        python3 examples/train_unitary_prep/train_unitary_prep.py --epochs 1
        python3 examples/train_state_prep/train_state_prep.py --epochs 1
        python3 examples/superdense_coding/superdense_coding_torchquantum.py
        python3 examples/regression/run_regression.py --epochs 1
        python3 examples/param_shift_onchip_training/param_shift.py
        python3 examples/mnist/mnist_2qubit_4class.py --epochs 1
        python3 examples/hadamard_grad/circ.py
        python3 examples/encoder_examples/encoder_8x2ry.py
        python3 examples/converter_tq_qiskit/convert.py
        python3 examples/amplitude_encoding_mnist/mnist_new.py --epochs 1
        python3 examples/amplitude_encoding_mnist/mnist_example.py --epochs 1
        python3 examples/PauliSumOp/pauli_sum_op.py
        python3 examples/regression/new_run_regression.py --epochs 1
        python3 examples/quanvolution/quanvolution_trainable_quantum_layer.py --epochs 1
        python3 examples/grover/grover_example_sudoku.py
        python3 examples/param_shift_onchip_training/param_shift.py
        python3 examples/quanvolution/quanvolution.py --epochs 1
        python3 examples/quantum_lstm/qlstm.py --epochs 1
        python3 examples/qaoa/max_cut_backprop.py --steps 1
        python3 examples/optimal_control/optimal_control.py --epochs 1
        python3 examples/optimal_control/optimal_control_gaussian.py --epochs 1
        python3 examples/optimal_control/optimal_control_multi_qubit.py --epochs 1
        python3 examples/save_load_example/save_load.py
        python3 examples/mnist/mnist.py --epochs 1

locally and it finishes fine with NumPy 1.26.1.

[01110011011101010110010001101111]

Yeah, thanks for the fix, haven’t yet looked at breaking changes from numpy 2.0. I’ll likely open a PR for that later.
Re: a review for this PR, I haven’t deal too much with our measure functions so will need to redirect the review to other maintainers.

[yannick-couzinie]

Thanks! I can reverse that commit on requirements.txt if need be at least the workflows run now, the linting problem is that expval is defined when running measurements.py as main, while expval is also the name of a function. The fix is just to rename the expval in the main block at the bottom, can include it here if you want it, but it is a really straightforward fix.

[01110011011101010110010001101111]

This looks good to me, thanks for the PR! I’ll merge into dev!