A walk with fastai2 - Tabular - Study Group and Online Lectures Megathread

Passing in empty list works !!

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Typo in 02_permutation… nb.
to = TabularPandas(…should be y_block=RegressionBlock()…) and not block_y =

They updated the syntax around a few days ago. I’ll go make that adjustment.

Edit: this has been fixed @Srinivas

Thanks

Thanks for the reply. I did not see them in the arguments in the doc thus thought they are deprecated. My bad!

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Hi @zdw2126062 I encountered the same error.
Does that mean having momentum does not have a positive effect on a tabular models?
Also, since momentum is not used will it be a good idea to use weight decay as an optimisation instead of momentum?

@AjayStark no see Sylvain comments about tabular_config. I’ll try to show an example next week.

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Oh, thanks for pointing out. Got it ! :slight_smile:

After assigning momentum using config=tabular_config(), how to pass config into tabular_learner() ?

Just pass it in as config. IE:

tabular_learner(dls, layers, config=config)

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Ooops silly one. Didn’t see config in the arguments list.

And is it same as creating a Tabularmodel first with the ps and embed_p

You can pass it in as below:-

config = tabular_config(ps=[0.001,0.01], embed_p = 0.04)

learn = tabular_learner(dls,
layers=[100,50],
config = config,
metrics=[accuracy])

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Yeah got it, Thank you :slight_smile:

@muellerzr when is the lesson4 going to be?


Just came to know about this, how are you currently doing Zach?. Hope all it’s well and do take adequate rest as required.

As mentioned earlier they are now on Wednesdays. I’m doing fine currently thank you for asking.

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@muellerzr thanks a lot for your passion when teaching! :heart_eyes:

I was watching your awesome video A walk with fastai2 - Tabular - Lesson 3 and I had a couple questions:

  1. Why is your test dataloader using df.iloc[:100]. Aren’t these rows used for training already? Or was this choice done just for the sake of illustration of how ClassConfusion works?

  2. When looking at the plots, in (<50K, >= 50K) the actual class was <50K and the predicted >=50K for the df.iloc[:100] that were wrongly classified. Is this statement correct? I just wanted to make sure.

  1. Where can I find reliable and understandable information for how fastai tabular embedding work? I understand how they are generated for NLP but to me this part is still very unclear for tabular data. :grimacing:

To everyone, any good courses you would recommend about explainability? I would like to learn more about how SHAP works and what the different plots mean.

Just for the sake of visualization :slight_smile:

Yup you’re correct!

See here, an article by Rachel back in 2018 (but nothing’s changed :wink: )

https://www.fast.ai/2018/04/29/categorical-embeddings/

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Here’s a Kaggle mini-series (I think that’s what it’s called) that looks pretty good. Covers permutation importance along with SHAP and a few others:

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Thanks a lot! Quick doubt. How can I extract a row from here?

I tried learn.dls.valid_ds.iloc[800,:] as I would in pandas but I get TypeError: only list-like objects are allowed to be passed to isin(), you passed a [slice]. Note that type(learn.dls.valid_ds) is not dataframe but fastai2.tabular.core.TabularPandas

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Promise I’m not ignoring you :slight_smile: I’ll be able to get back to you on this either Tuesday evening or Wednesday evening at the latest :slight_smile: Apologies!

Also in regards to this week, I’m currently working on traveling home which will be on Wednesday when we would normally do class, so for everyone’s ease it’ll be same time on Thursday. I appreciate your understanding and my apologies. Next week once we start NLP there shouldn’t be any issues whatsoever in terms of weird set backs thanks to covid (And those will be at our regular Wednesday time)

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