yzhao062/pyod

AutoEncoder does not generate a symmetric model

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#138 opened on Nov 3, 2019

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Description

Hi,

I plotted the model when printing the model summary: https://github.com/yzhao062/pyod/blob/da68f50ee79bd74777d2d406cac6dcfad412e599/pyod/models/auto_encoder.py#L187

And it seems that you added an extra layer at the beginning with the same dimension as the input. I don't know why this is required because it would generate an asymmetric model. Here is the model I printed out:

model

The final dimension would be like 645-645-100-100-500-9-500-100-100-645.

I think the problem might be caused by this line: https://github.com/yzhao062/pyod/blob/da68f50ee79bd74777d2d406cac6dcfad412e599/pyod/models/auto_encoder.py#L224

The performance is similar after I commented out the above line.

Please correct me if I miss something! Thanks!

Contributor guide

Research direction
Inspect the autoencoder model construction in pyod/models/auto encoder.py, specifically line 224, which adds an extra hidden layer with the same dimension as the input. This causes asymmetry. Commenting it out should restore symmetry. Verify by retraining and checking model summary.
Tech stack
python
Domain
machine learning
Issue type
Bug
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2
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1-3 hours
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Python
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75