Quickstart

Install

irm flex.levylab.org/install.ps1 | iex

This brings in the six default packages (flex-core, flex-protocols, flex-db, flex-datatypes, flex-exp, flex-drivers). No configuration is needed — data goes to HDF5 files and a SQLite database under your user data directory. (Developing FLEX itself, or on another OS? Install editable from a clone — see the README's Development section.)

Your first experiment (no hardware needed)

from flex import Experiment, Scan, sweep, SimulatedInstrument
import numpy as np

with Experiment("jane") as exp:
    sim = exp.add(SimulatedInstrument, "demo")
    gate = sim.add_sim_parameter("gate", unit="V")
    x = sim.add_sim_parameter("x", initial=0.5, unit="V")

    Scan(sweep(gate, np.linspace(0, 1, 101), delay=0.01)) \
        .measure(sim.parameters["x"]) \
        .on_abort(lambda: gate(0)) \
        .run(exp, name="gate sweep")

What happened:

• an experiment record was created (id, user, start/end time, instruments),
• the scan swept gate, read x at every point, and wrote both columns — with units — to an HDF5 file,
• a log file captured everything, and Jupyter cells are recorded as notes,
• if you had pressed Ctrl-C, the file would have been finalized, the measurement marked aborted, and the on_abort cleanup would have run.

Browse it:

flex experiments
flex measurements <experiment-id>

A real instrument

Any VISA instrument works the same way — drivers are one inheritance:

from flex_protocols import VISAInstrument

class Keithley2400(VISAInstrument):
    def __init__(self, name="k2400", resource="GPIB0::24::INSTR"):
        super().__init__(name, resource)
        self.voltage = self.add_parameter(
            "voltage", get_cmd="SOUR:VOLT?", set_cmd="SOUR:VOLT {}",
            get_parser=float, unit="V",
        )

with Experiment("jane") as exp:
    k = exp.add(Keithley2400, resource="GPIB0::24::INSTR")
    Scan(sweep(k.voltage, np.linspace(0, 1, 51), delay=0.1)) \
        .measure(current=lambda: k.query("MEAS:CURR?")) \
        .run(exp, name="IV")

flex new driver MyInstrument --protocol visa scaffolds this for you.

Measurements without scans

For full control, drive the measurement yourself:

with exp.measurement("noise vs time") as m:
    m.register(k.voltage)              # read on every point, with units
    for _ in range(1000):
        m.read_point(t=time.time())    # registered params + your columns
    m.add_array("spectrum", psd)       # free-form arrays
    m.add_note("AC line filter engaged")

Next steps

• Build an ecosystem — configure your lab's database, storage, data format, and hooks in one file.
• LevyLab guide — CESession and the Instrument Framework.
• Dashboard — manage packages and browse experiments in the browser (python -m flex dashboard).