Lesson 3 In-Class Discussion ✅

accuracy is a metric, not a loss function. You couldn’t train well with it because it has no gradients (they’re zero everywhere pretty much). The usual loss function used is cross entropy, but it depends on your task.

3 Likes

The function isn’t coded for that so you would have to tweak its implementation.

1 Like

I want to remind everyone that as of last week, the docs now have a working search function as well.

10 Likes

yes VGG is there

https://docs.fast.ai/vision.models.html
https://pytorch.org/docs/stable/torchvision/models.html

1 Like

You are right. I was in the branch release 1.0.15, thanks

They’re not plugged in the create_cnn function yet, as they’re a bit outdated, but it shouldn’t be too much work to make them work with fastai.

Yes, if you have three classes {A, B, C}
you can train three binary classifiers:
{A, not A}
{B , not B}
{C, not C}

1 Like

Could you give more detail how you choose the threshold?

1 Like

if we have just yes or no for a given object ,is no of class one or two?

Thank you!

You try and see which value works better :wink:

That’s two classes

Single classification with two classes. Multi class is when an object can have several tags.

2 Likes

Yeah, I didn’t seem to see them in the docs. But, I like the ones present already. They seem to be really cool.

LR plot is plot vs Validation loss or Training loss

what is the loss function used for planets?

1 Like

For the deployment app, we need to " Upload your trained model file (for example stage-2.pth ) to a cloud service like Google Drive or Dropbox". How can we directly upload that saved .pth to google drive? Or how to download it to local machine and then upload it?
Thank you.

@rachel another :slight_smile:

1 Like

It’s kind of the same since it’s training for the first time on data it hasn’t seen, but it’s the training loss.

pip install --upgrade fastai

Did you try this?

1 Like