The Snapshot¶
This notebook sheds some light on the snapshot of instruments.
NOTE: this notebook uses a depreated Loop construct for some of its examples. Please, instead, refer to Working with snapshots notebook from ``docs/examples/DataSet` <DataSet/Working%20with%20snapshots.ipynb>`__.
[1]:
import json
import os
from pprint import pprint
import qcodes as qc
from qcodes.instrument_drivers.mock_instruments import DummyInstrument
from qcodes.station import Station
from qcodes_loop.loops import Loop
# For this tutorial, we initialise our favourite pair of mock instruments,
# a DMM and a DAC
dmm = DummyInstrument('dmm', gates=['v1', 'v2'])
dac = DummyInstrument('dac', gates=['ch1', 'ch2'])
station = Station(dmm, dac)
Logging hadn't been started.
Activating auto-logging. Current session state plus future input saved.
Filename : C:\Users\a-halakh\.qcodes\logs\command_history.log
Mode : append
Output logging : True
Raw input log : False
Timestamping : True
State : active
Qcodes Logfile : C:\Users\a-halakh\.qcodes\logs\200324-30512-qcodes.log
False
The main point of having a Station is that it snapshots the state of all added instruments. But what does that mean? Recall that an instrument is, loosely speaking, a collection of Parameters.
Parameter snapshot¶
[2]:
# Each parameter has a snapshot, containing information about its current value,
# when that value was set, what the allowed values are, etc.
pprint(dmm.v1.snapshot())
{'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dmm_v1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'label': 'Gate v1',
'name': 'v1',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 18:47:43',
'unit': 'V',
'vals': '<Numbers -800<=v<=400>',
'value': 0}
Instrument snapshot¶
[3]:
# Each instrument has a snapshot that is basically the snapshots of all the parameters
pprint(dmm.snapshot())
{'__class__': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'functions': {},
'name': 'dmm',
'parameters': {'IDN': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dmm_IDN',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'label': 'IDN',
'name': 'IDN',
'post_delay': 0,
'raw_value': {'firmware': None,
'model': 'dmm',
'serial': None,
'vendor': None},
'ts': '2020-03-24 18:47:43',
'unit': '',
'vals': '<Anything>',
'value': {'firmware': None,
'model': 'dmm',
'serial': None,
'vendor': None}},
'v1': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dmm_v1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'label': 'Gate v1',
'name': 'v1',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 18:47:43',
'unit': 'V',
'vals': '<Numbers -800<=v<=400>',
'value': 0},
'v2': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dmm_v2',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'label': 'Gate v2',
'name': 'v2',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 18:47:43',
'unit': 'V',
'vals': '<Numbers -800<=v<=400>',
'value': 0}},
'submodules': {}}
Sweep snapshot¶
[4]:
# When running QCoDeS loops, something is being swept. This is controlled with the `sweep` of a parameter.
# Sweeps also have snapshots
a_sweep = dac.ch1.sweep(0, 10, num=25)
pprint(a_sweep.snapshot())
{'parameter': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dac_ch1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dac',
'inter_delay': 0,
'label': 'Gate ch1',
'name': 'ch1',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 18:47:43',
'unit': 'V',
'vals': '<Numbers -800<=v<=400>',
'value': 0},
'values': [{'first': 0.0, 'last': 10.0, 'num': 25, 'type': 'linear'}]}
Loop/Measurement snapshot¶
[5]:
# All this is of course nice since a snapshot is saved every time a measurement is
# performed. Let's see this in action with a Loop.
# This is a qcodes_loop.loop, sweeping a dac gate and reading a dmm voltage
lp = Loop(dac.ch1.sweep(0, 1, num=10), 0).each(dmm.v1)
# before the loop runs, the snapshot is quite modest; it contains the snapshots of
# the two involved parameters and the sweep
pprint(lp.snapshot())
{'__class__': 'qcodes.loops.ActiveLoop',
'actions': [{'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dmm_v1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'label': 'Gate v1',
'name': 'v1',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 18:47:43',
'unit': 'V',
'vals': '<Numbers -800<=v<=400>',
'value': 0}],
'delay': 0,
'sweep_values': {'parameter': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dac_ch1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dac',
'inter_delay': 0,
'label': 'Gate ch1',
'name': 'ch1',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 18:47:43',
'unit': 'V',
'vals': '<Numbers -800<=v<=400>',
'value': 0},
'values': [{'first': 0.0,
'last': 1.0,
'num': 10,
'type': 'linear'}]},
'then_actions': []}
[6]:
# After the loop has run, the dataset contains more information, in particular the
# snapshots for ALL parameters off ALL instruments in the station
data = lp.run('data/dataset')
pprint(data.snapshot())
# This is the snapshot that get's saved to disk alongside your data.
# It's worthwhile familiarising yourself with it, so that you may retrieve
# valuable information down the line!
Started at 2020-03-24 18:47:43
DataSet:
location = 'data/2020-03-24/#014_{name}_18-47-43'
<Type> | <array_id> | <array.name> | <array.shape>
Setpoint | dac_ch1_set | ch1 | (10,)
Measured | dmm_v1 | v1 | (10,)
Finished at 2020-03-24 18:47:43
{'__class__': 'qcodes.data.data_set.DataSet',
'arrays': {'dac_ch1_set': {'__class__': 'qcodes.data.data_array.DataArray',
'action_indices': (),
'array_id': 'dac_ch1_set',
'full_name': 'dac_ch1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dac',
'inter_delay': 0,
'is_setpoint': True,
'label': 'Gate ch1',
'name': 'ch1',
'post_delay': 0,
'raw_value': 0,
'shape': (10,),
'unit': 'V',
'vals': '<Numbers -800<=v<=400>'},
'dmm_v1': {'__class__': 'qcodes.data.data_array.DataArray',
'action_indices': (0,),
'array_id': 'dmm_v1',
'full_name': 'dmm_v1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'is_setpoint': False,
'label': 'Gate v1',
'name': 'v1',
'post_delay': 0,
'raw_value': 0,
'shape': (10,),
'unit': 'V',
'vals': '<Numbers -800<=v<=400>'}},
'formatter': 'qcodes.data.gnuplot_format.GNUPlotFormat',
'io': '<DiskIO, '
"base_location='C:\\\\Users\\\\a-halakh\\\\Documents\\\\Microsoft\\\\Qcodes\\\\docs\\\\examples\\\\legacy'>",
'location': 'data/2020-03-24/#014_{name}_18-47-43',
'loop': {'__class__': 'qcodes.loops.ActiveLoop',
'actions': [{'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dmm_v1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'label': 'Gate v1',
'name': 'v1',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 18:47:43',
'unit': 'V',
'vals': '<Numbers -800<=v<=400>',
'value': 0}],
'delay': 0,
'sweep_values': {'parameter': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dac_ch1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dac',
'inter_delay': 0,
'label': 'Gate ch1',
'name': 'ch1',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 18:47:43',
'unit': 'V',
'vals': '<Numbers -800<=v<=400>',
'value': 0},
'values': [{'first': 0.0,
'last': 1.0,
'num': 10,
'type': 'linear'}]},
'then_actions': [],
'ts_end': '2020-03-24 18:47:43',
'ts_start': '2020-03-24 18:47:43',
'use_threads': 'data/dataset'},
'station': {'components': {},
'config': None,
'default_measurement': [],
'instruments': {'dac': {'__class__': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'functions': {},
'name': 'dac',
'parameters': {'IDN': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dac_IDN',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dac',
'inter_delay': 0,
'label': 'IDN',
'name': 'IDN',
'post_delay': 0,
'raw_value': {'firmware': None,
'model': 'dac',
'serial': None,
'vendor': None},
'ts': '2020-03-24 '
'18:47:43',
'unit': '',
'vals': '<Anything>',
'value': {'firmware': None,
'model': 'dac',
'serial': None,
'vendor': None}},
'ch1': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dac_ch1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dac',
'inter_delay': 0,
'label': 'Gate ch1',
'name': 'ch1',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 '
'18:47:43',
'unit': 'V',
'vals': '<Numbers '
'-800<=v<=400>',
'value': 0},
'ch2': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dac_ch2',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dac',
'inter_delay': 0,
'label': 'Gate ch2',
'name': 'ch2',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 '
'18:47:43',
'unit': 'V',
'vals': '<Numbers '
'-800<=v<=400>',
'value': 0}},
'submodules': {}},
'dmm': {'__class__': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'functions': {},
'name': 'dmm',
'parameters': {'IDN': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dmm_IDN',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'label': 'IDN',
'name': 'IDN',
'post_delay': 0,
'raw_value': {'firmware': None,
'model': 'dmm',
'serial': None,
'vendor': None},
'ts': '2020-03-24 '
'18:47:43',
'unit': '',
'vals': '<Anything>',
'value': {'firmware': None,
'model': 'dmm',
'serial': None,
'vendor': None}},
'v1': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dmm_v1',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'label': 'Gate v1',
'name': 'v1',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 '
'18:47:43',
'unit': 'V',
'vals': '<Numbers '
'-800<=v<=400>',
'value': 0},
'v2': {'__class__': 'qcodes.instrument.parameter.Parameter',
'full_name': 'dmm_v2',
'instrument': 'qcodes.instrument_drivers.mock_instruments.DummyInstrument',
'instrument_name': 'dmm',
'inter_delay': 0,
'label': 'Gate v2',
'name': 'v2',
'post_delay': 0,
'raw_value': 0,
'ts': '2020-03-24 '
'18:47:43',
'unit': 'V',
'vals': '<Numbers '
'-800<=v<=400>',
'value': 0}},
'submodules': {}}},
'parameters': {}}}
[ ]: