These examples show how to transmit a numeric multi-channel time series through LSL:
These examples do the same as before, but now transmit the data at the granularity of chunks. For the purposes of network transmission the same effect can be achieved by creating the inlet or outlet with an extra argument to indicate that multiple samples should be batched into a chunk for transmission.
However, since MATLAB's interpreter is relatively slow, the library calls should be made in a vectorized manner, i.e. at chunk granularity, whenever possible (at least for high-rate streams).
Note that for LSL the data is always a linear sequence of samples and data that is pushed as samples can be pulled out as chunks or vice versa:
These examples show a special-purpose use case that is mostly relevant for stimulus-presentation programs or other applications that want to emit 'event' markers or other application state.
The stream here is single-channel and has irregular sampling rate, but the value per channel is a string:
The last example shows how to attach properly formatted meta-data to a stream, and how to read it out again at the receiving end. While meta-data is strictly optional, it is very useful to make streams self-describing. LSL has adopted the convention to name meta-data fields according to the XDF file format specification whenever the content type matches (for example EEG, Gaze, MoCap, VideoRaw, etc); the spec is here.
Note that some older example programs (SendData/ReceiveData) predate this convention and name the channels inconsistently.
To run these examples, you must have added the folder include/lsl_matlab to your MATLAB path (recursively).
You can do this either via the File/Path... menu or via the command addpath(genpath('your_path_to/liblsl-1.xx/include/lsl_matlab'))
Also, if you have rebuilt the library, make sure that liblsl-1.xx/include/lsl_matlab/bin contains a copy of the library files in the liblsl-1.xx/bin.