Difference between revisions of "DataHub"

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Line 53: Line 53:
  
 
import time
 
import time
−
import numpy as np
+
import random
 
import keyboard
 
import keyboard
−
import random
+
from pylsl import StreamInfo, StreamOutlet
−
from pylsl import StreamInfo, StreamOutlet, local_clock
 
−
from LSLsettings import MarkerStreamSettings, DynamicMultiChannelStreamSettings
 
  
−
print(f"Setting up streams...")
+
from pylsl import local_clock
−
marker_settings = MarkerStreamSettings()
 
  
−
# info marker StreamInfo, outlet
+
# --- Setup Marker Stream ---
 +
print("Setting up marker stream...")
 
marker_info = StreamInfo(
 
marker_info = StreamInfo(
−
     name=marker_settings.stream_name,
+
     name="MarkerStream",
−
     type=marker_settings.stream_type,
+
     type="Markers",
−
     channel_count=marker_settings.channel_count,
+
     channel_count=1,
−
     nominal_srate=marker_settings.sample_rate,
+
     nominal_srate=0, # Irregular sampling
−
     channel_format=marker_settings.channel_format,
+
     channel_format="string",
−
     source_id=marker_settings.source_id
+
     source_id="MarkerSource"
 
)
 
)
−
marker_outlet = StreamOutlet(marker_info, chunk_size=marker_settings.push_chunk_size)
+
marker_outlet = StreamOutlet(marker_info, chunk_size=1)
  
−
data_settings = DynamicMultiChannelStreamSettings(
+
# --- Setup Data Stream ---
−
    n_channels=4,
+
print("Setting up data stream...")
−
     stream_name="TestStream",
+
data_info = StreamInfo(
−
     stream_type="TestData",
+
     name="TestStream",
−
     sample_rate=100,
+
     type="TestData",
−
     channel_names=["A", "B", "C", "D"]
+
     channel_count=4,
 +
    nominal_srate=100,
 +
     channel_format="float32",
 +
    source_id="TestStream_Source"
 
)
 
)
  
−
# info data StreamInfo, outlet
+
channels = data_info.desc().append_child("channels")
−
data_info = StreamInfo(
+
for name in ["A", "B", "C", "D"]:
−
    name=data_settings.stream_name,
+
     chan = channels.append_child("channel")
−
    type=data_settings.stream_type,
+
     chan.append_child_value("name", name)
−
     channel_count=data_settings.channel_count,
+
     chan.append_child_value("unit", "unitless")
−
     nominal_srate=data_settings.sample_rate,
+
     chan.append_child_value("type", "TestData")
−
     channel_format=data_settings.channel_format,
 
−
     source_id=data_settings.source_id
 
−
)
 
−
data_outlet = StreamOutlet(data_info, chunk_size=data_settings.push_chunk_size)
 
  
−
running = True
+
data_outlet = StreamOutlet(data_info, chunk_size=1)
−
marker_outlet.push_sample(["Start"])
 
−
buffer_dtype = object if data_settings.channel_format == "string" else float
 
−
buffer_in = np.array(data_settings.default_buffer, dtype=buffer_dtype)
 
  
 +
# --- Start Streaming ---
 
print("Start streaming... Press 'q' to stop.")
 
print("Start streaming... Press 'q' to stop.")
 +
marker_outlet.push_sample(["Start"])
  
−
while not(keyboard.is_pressed('q')):
+
while not keyboard.is_pressed('q'):
−
 
+
     random_numbers = [random.randint(1, 2) for _ in range(4)]
−
     random_numbers = [random.randint(0, 1) for _ in range(4)]
 
−
    random_numbers = [num + 1 for num in random_numbers]
 
 
     data_outlet.push_sample(random_numbers)
 
     data_outlet.push_sample(random_numbers)
−
 
+
     time.sleep(0.01)
−
     time.sleep(data_settings.push_interval)
 
  
 
marker_outlet.push_sample(["Stop"])
 
marker_outlet.push_sample(["Stop"])
−
 
+
print("Streaming stopped.")
−
</syntaxhighlight>
 
−
 
 
−
the settings.py file for LSL:
 
−
<syntaxhighlight lang="python" line>
 
−
# settings.py
 
−
 
 
−
class BaseSettings:
 
−
    """Basisklasse met standaardinstellingen voor een LSL stream."""
 
−
    def __init__(self):
 
−
        self.stream_name = "BaseStream"
 
−
        self.stream_type = "Unknown"
 
−
        self.channel_count = 1
 
−
        self.sample_rate = 0
 
−
        self.channel_format = "float32"
 
−
        self.source_id = "BaseSource"
 
−
 
 
−
        self.channel_names = []
 
−
        self.push_chunk_size = 1
 
−
        self.push_interval = 0.001
 
−
 
 
−
        self.use_random_data = False
 
−
        self.dummy_string = "Test"
 
−
        self.random_string_options = ["A", "B", "C"]
 
−
 
 
−
        self.verbose = True
 
−
        self.quit_method = "psychopy"
 
−
        self.user_stop_message = "Press ENTER/RETURN to stop acquisition."
 
−
 
 
−
        self.default_buffer = ["Test"]
 
−
 
 
−
        # the scope is not implemented yet
 
−
        self.scope = "lan"
 
−
 
 
−
    def get_stream_options(self):
 
−
        if self.scope in ["local", "lan", "internet"]:
 
−
            return dict()
 
−
        else:
 
−
            raise ValueError(f"Unknown scope: {self.scope}")
 
−
 
 
−
 
 
−
class DynamicMultiChannelStreamSettings(BaseSettings):
 
−
    def __init__(
 
−
        self,
 
−
        n_channels=8,
 
−
        stream_name="DynamicStream",
 
−
        stream_type="EEG",
 
−
        sample_rate=256,
 
−
        channel_format="float32",
 
−
        channel_names=None
 
−
    ):
 
−
        super().__init__()
 
−
        self.stream_name = stream_name
 
−
        self.stream_type = stream_type
 
−
        self.channel_count = n_channels
 
−
        self.sample_rate = sample_rate
 
−
        self.channel_format = channel_format
 
−
        self.source_id = f"{stream_name}_Source"
 
−
 
 
−
        if channel_names is not None:
 
−
            if len(channel_names) != n_channels:
 
−
                raise ValueError(f"Number of channel names ({len(channel_names)}) does not match n_channels ({n_channels})")
 
−
            self.channel_names = channel_names
 
−
        else:
 
−
            self.channel_names = [f"Chan{i+1}" for i in range(n_channels)]
 
−
 
 
−
        self.default_buffer = [0.0 for _ in range(n_channels)]
 
−
 
 
−
class MarkerStreamSettings(BaseSettings):
 
−
    def __init__(self):
 
−
        super().__init__()
 
−
        self.stream_name = "MarkerStream"
 
−
        self.stream_type = "Markers"
 
−
        self.channel_count = 1
 
−
        self.sample_rate = 0  # 0 Hz = irregular sampling
 
−
        self.channel_format = "string"
 
−
        self.source_id = "MarkerSource"
 
−
 
 
−
        self.channel_names = []  # niet nodig voor markers
 
−
        self.default_buffer = ["TestMarker"]
 
 
</syntaxhighlight>
 
</syntaxhighlight>
  

Latest revision as of 11:24, 28 April 2025

DataHub
Developer(s)Christian Kothe; Chadwick Boulay.
Development status-in development-
Written inC, C++, Python, Java, C#, MATLAB
Operating systemWindows, Linux, MacOS, Android, iOS
TypeData collection
LicenseOpen source
WebsiteLSL webpage

Resources

DataHub
Downloads
Manuals
Templates

The DataHub Makes use of the lab streaming layer. The lab streaming layer (LSL) is a system for the unified collection of measurement time series in research experiments that handles both the networking, time-synchronization, (near-) real-time access as well as optionally the centralized collection, viewing and disk recording of the data.


Installation

Our support for LSL is mainly done in python. Download python here: Please choose a 64 bit version.. Run the installer and make sure to add Python to the file path (it's an option in the installer). Open a command prompt, start with upgrading the pip installer by typing:
c:>python -m pip install --upgrade pip
Then:
c:>pip install pylsl

more info: cross platform pylsl

Versions

The TSG uses the version 1.15.0. Open a command and type the following to find the version used:

c:>python
>>> import pylsl
>>> print(pylsl.__version__)

Usage

Python

Example demonstrating how to send LSL stream and marker data: 

 1#!/usr/bin/env python3.10
 2# -*- coding: utf-8 -*-
 3
 4import time
 5import random
 6import keyboard
 7from pylsl import StreamInfo, StreamOutlet
 8
 9from pylsl import local_clock
10
11# --- Setup Marker Stream ---
12print("Setting up marker stream...")
13marker_info = StreamInfo(
14    name="MarkerStream",
15    type="Markers",
16    channel_count=1,
17    nominal_srate=0,  # Irregular sampling
18    channel_format="string",
19    source_id="MarkerSource"
20)
21marker_outlet = StreamOutlet(marker_info, chunk_size=1)
22
23# --- Setup Data Stream ---
24print("Setting up data stream...")
25data_info = StreamInfo(
26    name="TestStream",
27    type="TestData",
28    channel_count=4,
29    nominal_srate=100,
30    channel_format="float32",
31    source_id="TestStream_Source"
32)
33
34channels = data_info.desc().append_child("channels")
35for name in ["A", "B", "C", "D"]:
36    chan = channels.append_child("channel")
37    chan.append_child_value("name", name)
38    chan.append_child_value("unit", "unitless")
39    chan.append_child_value("type", "TestData")
40
41data_outlet = StreamOutlet(data_info, chunk_size=1)
42
43# --- Start Streaming ---
44print("Start streaming... Press 'q' to stop.")
45marker_outlet.push_sample(["Start"])
46
47while not keyboard.is_pressed('q'):
48    random_numbers = [random.randint(1, 2) for _ in range(4)]
49    data_outlet.push_sample(random_numbers)
50    time.sleep(0.01)
51
52marker_outlet.push_sample(["Stop"])
53print("Streaming stopped.")

Matlab

Please, read the instructions on the GitHub labstreaminglayer website (https://github.com/labstreaminglayer/liblsl-Matlab) on how to prepare Matlab to work with LSL. You can either use the latest release for your Matlab version, or if that doesn't workout well, build it from the source files. Make sure to add the liblsl-Matlab folder to your path recursively to make it available to your own scripts.

A short example for sending lsl streaming data: 

 1%% instantiate the library
 2disp('Loading library...');
 3lib = lsl_loadlib();
 4
 5% make a new stream outlet
 6disp('Creating a new streaminfo...');
 7info = lsl_streaminfo(lib,'BioSemi','EEG',8,100,'cf_float32','sdfwerr32432');
 8
 9disp('Opening an outlet...');
10outlet = lsl_outlet(info);
11
12% send data into the outlet, sample by sample
13disp('Now transmitting data...');
14while true
15    outlet.push_sample(randn(8,1));
16    pause(0.01);
17end

A short example for receiving lsl streaming data: 

 1%% instantiate the library
 2disp('Loading the library...');
 3lib = lsl_loadlib();
 4
 5% resolve a stream...
 6disp('Resolving an EEG stream...');
 7result = {};
 8while isempty(result)
 9    result = lsl_resolve_byprop(lib,'type','EEG'); end
10
11% create a new inlet
12disp('Opening an inlet...');
13inlet = lsl_inlet(result{1});
14
15disp('Now receiving data...');
16while true
17    % get data from the inlet
18    [vec,ts] = inlet.pull_sample();
19    % and display it
20    fprintf('%.2f\t',vec);
21    fprintf('%.5f\n',ts);
22end
Retrieved from "http://tsgdoc.socsci.ru.nl/index.php?title=DataHub&oldid=5972"