Hi! I'm using MLForecast for multiple unique ids, ...
# mlforecast
y
Hi! I'm using MLForecast for multiple unique ids, and I'm trying to understand how does the model work in terms of learning between different series (I'm using the LGBM regressor). Thanks!
j
the model is trained on all series
y
How does it account for the unique ID then? Since it's not a feature...
When doing inference for a series that was in the training data, will it give more weight to the learning from that specific series or is it just one model regardless of the unique id? From the explanation online it sounds like the unique id matters.
j
the id is only used to generate the features but it can be a feature as well if you provide it through
static_features
y
So if I don't use the unique id as a static feature explicitly, once the model is trained and we are doing inference there's no importance to the unique_id?....
j
it's one model, so it doesn't even know it's dealing with different series unless you provide it as a static feature, in which case it'll be used as a categorical
y
oh, interesting. So we don't really need the unique id once the model is trained
j
you need it for the forecasts because we generate future dates as a convenience, but it's just for that, convenience
👍 1
y
understood. Thank you for clarifying! one last clarification then - for training purposes, the unique_id is only used to generate features, and it does not "learn more" from series with the same unique id?
j
the unique_id is only used to generate features, and it does not "learn more" from series with the same unique id?
exactly. the model just sees all of the series at the same time and doesn't care about which is which
y
ok, thanks again for the clarification!