Coremltools & Pytorch incompatibility

Part 1 (2020)
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  • The new Fastai framework requires torch 1.7
  • coremltools does not work with torch version above 1.6.

My model is created using the new Fastai (Spring 2020) and now I cannot convert it to a CoreML model (to be used in iOS).

This link describes the problem with coremltools and torch version 1.7: https://github.com/ultralytics/yolov5/issues/1667

Is it possible to train the network using the latest Fastai and then load it using torch 1.6 so that it can be converted to coreML using coremltools 4.0?

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You can get just the model weights using learn.save(). Then you should be able to load it in a PyTorch model that is defined in the same way. Just note that you will have to replicate the fastai inference code in pure PyTorch. I think if you are just using the model weights, training with the latest version of fastai will work.

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You should be able to install coremltools=3.4 which lets you convert to coreml to ā€˜old fashionā€™ way. :slight_smile:

Or you can use the automated solution: https://course.fast.ai/deployment_seeme_ai which automatically converts to coreml, onnx and tflite.

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Update (but need to verify): The issue seems to be fixed:

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Thanks. Thatā€™s a 3rd party service which is going to charge soon after their beta is over.

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Thanks. I ended up using the head branch from coremltool repo which is compatible with PyTorch 1.7

!pip install -Uqq git+https://github.com/apple/coremltools.git@master
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Thanks for the feedback.

Iā€™m aware of the ā€œNBā€ added to the docs page. Iā€™m the founder of SeeMe.ai, so I can inform you that although there is no official pricing yet, Iā€™m working hard on providing a generous free tier.

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Glad that worked for you, Iā€™ll try to test the coremltools 4.0 from pip which I mentionedā€¦