a library for connecting to experiments in python
import matplotlib.pyplot as plt
import numpy as np
from practable.core import Experiment
import time
messages = []
#modify with actual group code and experiment name
with Experiment('g-open-x3fca8','Spinner 51 (Open Days)', exact=True) as expt:
# Command a step of 2 radians & collect the data
expt.command('{"set":"mode","to":"stop"}')
expt.command('{"set":"mode","to":"position"}')
expt.command('{"set":"parameters","kp":1,"ki":0,"kd":0}')
time.sleep(0.5)
expt.command('{"set":"position","to":2}')
expt.ignore(0.5)
messages = expt.collect(1.5)
# Process the data
ts = expt.extract_series(messages, "t")
ds = expt.extract_series(messages, "d")
cs = expt.extract_series(messages, "c")
t = np.array(ts)
t = t - t[0]
# Plot the data
plt.figure()
plt.plot(t/1e3,ds,'-b',label="position")
plt.plot(t/1e3,cs,':r',label="set point")
plt.xlabel("time(s)")
plt.ylabel("position(rad)")
plt.legend()
This script produces the following text output
Command: {"set":"mode","to":"stop"}
Command: {"set":"mode","to":"position"}
Command: {"set":"parameters","kp":1,"ki":0,"kd":0}
Command: {"set":"position","to":2}
Ignoring messages for 0.5 seconds |██████████████████████████████████████████████████| 100.0% Complete
Collecting messages for 1.5 seconds |██████████████████████████████████████████████████| 100.0% Complete
An a graph:
A user name is obtained and stored locally.
Bookings last only as long as the experiment is needed, because they are cancelled when the with
environment exits. The default booking duration is 3 min.
You can use an existing booking by specifying user="cxxxxxxxxxx"
where the username is found on the user
tab of the booking system that holds the booking.
Other practable
instances can be accessed by specifying it e.g. booking-server="https://some.booking.server"
Recommend python >= 3.8 because we're using websockets 12.0