Unable to play custom pulses with QM

[andrea-pasquale]

The following code is failing using main.

import numpy as np
from qibolab import create_platform, Custom, Pulse, PulseSequence

platform = create_platform("qw11q")

sequence = PulseSequence()

drive_channel = platform.qubits["D1"].drive
duration = 40
pulse = Pulse(amplitude=0.01,
              duration=duration,
              envelope=Custom(i_=np.ones(duration), q_=np.zeros(duration)))
sequence.append((drive_channel, pulse))


sequence |= platform.natives.single_qubit["D1"].MZ()

platform.connect()
result = platform.execute([sequence])
platform.disconnect()

Here is the error.

2024-11-14 14:12:34,561 - qm - INFO     - Starting session: 31c229f4-6d22-4c91-baec-345506575398
2024-11-14 14:12:36,796 - qm - INFO     - Octave "octave5" Health check passed, current temperature 59
2024-11-14 14:12:37,530 - qm - INFO     - Octave "octave6" Health check passed, current temperature 58
2024-11-14 14:12:37,530 - qm - INFO     - Performing health check
2024-11-14 14:12:37,550 - qm - WARNING  - Health check warning: Inter-OPX connectivity issues in OPX: con1. Missing ports are: 12, 11, 10, 9. See QM-App for more info.
2024-11-14 14:12:37,550 - qm - WARNING  - Health check warning: Inter-OPX connectivity issues in OPX: con2. Missing ports are: 12, 11, 10, 9. See QM-App for more info.
2024-11-14 14:12:37,551 - qm - WARNING  - Health check warning: Inter-OPX connectivity issues in OPX: con3. Missing ports are: 12, 11, 10, 9. See QM-App for more info.
2024-11-14 14:12:37,551 - qm - WARNING  - Health check warning: Inter-OPX connectivity issues in OPX: con4. Missing ports are: 12, 11, 10, 9. See QM-App for more info.
2024-11-14 14:12:37,551 - qm - WARNING  - Health check warning: Inter-OPX connectivity issues in OPX: con5. Missing ports are: 12, 11, 10, 9. See QM-App for more info.
2024-11-14 14:12:37,551 - qm - WARNING  - Health check warning: Inter-OPX connectivity issues in OPX: con6. Missing ports are: 12, 11, 10, 9. See QM-App for more info.
2024-11-14 14:12:37,551 - qm - WARNING  - Health check warning: Inter-OPX connectivity issues in OPX: con7. Missing ports are: 12, 11, 10, 9. See QM-App for more info.
2024-11-14 14:12:37,551 - qm - WARNING  - Health check warning: Inter-OPX connectivity issues in OPX: con8. Missing ports are: 12, 11, 10, 9. See QM-App for more info.
2024-11-14 14:12:37,551 - qm - WARNING  - Health check warning: Inter-OPX connectivity issues in OPX: con9. Missing ports are: 12, 11, 10, 9. See QM-App for more info.
2024-11-14 14:12:37,551 - qm - INFO     - Health check passed
Connected to: Rohde&Schwarz SGS100A (serial:1416.0505k02/114164, firmware:4.2.76.0-4.30.046.295) in 0.16s
Traceback (most recent call last):
  File "/nfs/users/andrea.pasquale/qibocal/test_qm.py", line 17, in <module>
    result = platform.execute([sequence])
  File "/nfs/users/andrea.pasquale/qibolab/src/qibolab/_core/platform/platform.py", line 290, in execute
    results |= self._execute(b, options, configs, sweepers)
  File "/nfs/users/andrea.pasquale/qibolab/src/qibolab/_core/platform/platform.py", line 224, in _execute
    new_result = instrument.play(configs, sequences, options, sweepers)
  File "/nfs/users/andrea.pasquale/qibolab/src/qibolab/_core/instruments/qm/controller.py", line 493, in play
    self.register_pulses(configs, sequence)
  File "/nfs/users/andrea.pasquale/qibolab/src/qibolab/_core/instruments/qm/controller.py", line 342, in register_pulses
    self.register_pulse(id, configs[id], pulse)
  File "/nfs/users/andrea.pasquale/qibolab/src/qibolab/_core/instruments/qm/controller.py", line 322, in register_pulse
    return self.config.register_iq_pulse(channel, pulse, max_voltage)
  File "/nfs/users/andrea.pasquale/qibolab/src/qibolab/_core/instruments/qm/config/config.py", line 158, in register_iq_pulse
    op = operation(pulse)
  File "/nfs/users/andrea.pasquale/qibolab/src/qibolab/_core/instruments/qm/config/pulses.py", line 25, in operation
    return str(hash(pulse))
  File "/nfs/users/andrea.pasquale/default/lib/python3.10/site-packages/pydantic/_internal/_model_construction.py", line 446, in hash_func
    return hash(getter(self.__dict__))
  File "/nfs/users/andrea.pasquale/default/lib/python3.10/site-packages/pydantic/_internal/_model_construction.py", line 446, in hash_func
    return hash(getter(self.__dict__))
TypeError: unhashable type: 'numpy.ndarray'
srun: error: fahid: task 0: Exited with exit code 1

I am guessing that the error might be caused by the fact that Custom accepts arrays which qm doesn't seems to like arrays when playing with custom pulses. Any ideas @alecandido @stavros11?

[alecandido]

I am guessing that the error might be caused by the fact that Custom accepts arrays which qm doesn't seems to like arrays when playing with custom pulses.

Nope, it's just our fault, not really QM related...

We need to name pulses for the upload, almost in every driver (actually, in all of them, ttbomk). Naming automatically is not completely trivial, and there are two main options:

1. assigning them a serial
2. make them content dependent (hashing)

Number 1. is cumbersome, since you need to always have access to a unique container, and grow it. Moreover, the second option is coming with the additional benefit of automatically deduplicating what we are uploading to the instrument (since identical pulses will have identical hashes).

Unfortunately, NumPy arrays are unhashable by default, since they are mutable (thus unsuitable for places where hashes are typically used, e.g. dict keys). But Custom is the only envelope which is parametrized by an entire array. And that's where the problem is being generated.

What we can do is to manually define the __hash__ of the Custom envelope, by hashing the data buffer of the NumPy array, instead of attempting to hash the entire Python object (which will correctly refuse to do it, generating the reported error).

[andrea-pasquale]

Since there is already an indentier for pulses in id, we could also just make qm use that instead of referring to its hash, no?

[andrea-pasquale]

After discussing offline, we've decided to fix the issue in the following way #1101

What we can do is to manually define the __hash__ of the Custom envelope, by hashing the data buffer of the NumPy array, instead of attempting to hash the entire Python object (which will correctly refuse to do it, generating the reported error).

Using the pulse id doesn't work because it will duplicate the waveform for each pulse with the same waveform.