Machine Learning

1 readers

1 users here now

Community Rules:

Be nice. No offensive behavior, insults or attacks: we encourage a diverse community in which members feel safe and have a voice.
Make your post clear and comprehensive: posts that lack insight or effort will be removed. (ex: questions which are easily googled)
Beginner or career related questions go elsewhere. This community is focused in discussion of research and new projects that advance the state-of-the-art.
Limit self-promotion. Comments and posts should be first and foremost about topics of interest to ML observers and practitioners. Limited self-promotion is tolerated, but the sub is not here as merely a source for free advertisement. Such posts will be removed at the discretion of the mods.

founded 1 year ago

MODERATORS

communick@academy.garden

[D] Branching Submodel in Keras and Tensorflow (alien.top)

submitted 11 months ago by work_account_mp@alien.top to c/machinelearning@academy.garden

4 comments fedilink hide all child comments

Let's say I have a model, which has 2 inputs. The first input is a number, and the second input is another number, which in reality is a class.

This model is split into 2 submodels. First sub-model works on the input, and the second sub-model works on the output of the first sub-model.

The value of the first input will very greatly by the output of the second. Thus, I wish to be able to have multiple candidates of the first sub-model, and dynamically select which one to use at each step, both during training and inference, based on the value (class) of the second input.

I did not manage to achieve this. I tried using the tf.cond, the tf.switch_case and several other things, but I never managed. When I asked chat GPT it said I should be using PyTorch for this. Is there really no way to do this ?

top 4 comments

sorted by: hot top controversial new old

[–] iateatoilet@alien.top 1 points 11 months ago (1 children)

Sounds like you want a mixture of experts for the first model, with the categorical distribution a function of the second model output. You can put this together straightforwardly in tf/pytorch/whatever, but will be lower level to implement (ie if you think there's a keras layer or something it is unlikely)

[–] work_account_mp@alien.top 1 points 11 months ago (1 children)

I'm not sure what you mean to be honest. I have a model where the first part is a submodel that is then used later on in the main model. Since there are different behaviour patterns here depending on the category (second input) i was wondering if it would be possible to have say 4 submodels corresponding with 4 classes, and use the corresponding one both during training when updating weights, and also during inference.

something like

value = Input()
categ = Input()

dense0, dense1 = Dense(5), Dense(5)

if categ == 0:
    first_layer = dense0
else:
    first_layer = dense1

# use first_layer accordingly...

[–] puppet_pals@alien.top 1 points 11 months ago (1 children)

Looks good. You probably want something like:

tf.cond(categ==0, dense0(inputs), dense1(inputs))

[–] work_account_mp@alien.top 1 points 11 months ago

I've got 8 categories and a lot of data, so the problem with this is that it becomes really slow, because it expects the inputs to have been passed through already.