Migrating Evaluating and exporting scikit-learn metrics in a Keras callback example to Keras 3

[sitamgithub-MSIT]

This PR changes the Evaluating and exporting scikit-learn metrics in a Keras callback example to keras 3.0 [TF Only Backend].

For example, here is the notebook link provided:
https://colab.research.google.com/drive/1rG2dhTVwJI4_FV3zgNtaxeq2lF7TN-Y1?usp=sharing

cc: @divyashreepathihalli @fchollet

The following describes the Git difference for the changed files:

Changes:

diff --git a/examples/keras_recipes/sklearn_metric_callbacks.py b/examples/keras_recipes/sklearn_metric_callbacks.py
index d40cda34..9839b35d 100644
--- a/examples/keras_recipes/sklearn_metric_callbacks.py
+++ b/examples/keras_recipes/sklearn_metric_callbacks.py
@@ -33,9 +33,10 @@ import os
 
 os.environ["KERAS_BACKEND"] = "tensorflow"
 
-import tensorflow as tf
-import keras as keras
+import keras
+from keras import ops
 from keras import layers
+import tensorflow as tf
 from sklearn.metrics import jaccard_score
 import numpy as np
 import os
@@ -56,7 +57,7 @@ class JaccardScoreCallback(keras.callbacks.Callback):
         self.keras_metric.reset_state()
         predictions = self.model.predict(self.x_test)
         jaccard_value = jaccard_score(
-            np.argmax(predictions, axis=-1), self.y_test, average=None
+            ops.argmax(predictions, axis=-1), self.y_test, average=None
         )
         self.keras_metric.update_state(jaccard_value)
         self._write_metric(
@@ -89,8 +90,8 @@ input_shape = (28, 28, 1)
 x_train = x_train.astype("float32") / 255
 x_test = x_test.astype("float32") / 255
 # Make sure images have shape (28, 28, 1)
-x_train = np.expand_dims(x_train, -1)
-x_test = np.expand_dims(x_test, -1)
+x_train = ops.expand_dims(x_train, -1)
+x_test = ops.expand_dims(x_test, -1)
 print("x_train shape:", x_train.shape)
 print(x_train.shape[0], "train samples")
 print(x_test.shape[0], "test samples")
@@ -120,7 +121,7 @@ epochs = 15
 
 model.compile(loss="categorical_crossentropy", optimizer="adam", metrics=["accuracy"])
 callbacks = [
-    JaccardScoreCallback(model.name, x_test, np.argmax(y_test, axis=-1), "logs")
+    JaccardScoreCallback(model.name, x_test, ops.argmax(y_test, axis=-1), "logs")
 ]
 model.fit(
     x_train,
(END)

[sitamgithub-MSIT]

The Tensorflow backend worked well. For other backends, validation_split was a problem. So, I tried with validation_data instead but still got an attribute error.

If the changes are all approved in the.py file,. Then I will change the rest of the files accordingly, with updated dates.

[fchollet]

For other backends, validation_split was a problem. So, I tried with validation_data instead but still got an attribute error.

What was the error in either case? Can you share a Colab to reproduce?

[sitamgithub-MSIT]

For other backends, validation_split was a problem. So, I tried with validation_data instead but still got an attribute error.

What was the error in either case? Can you share a Colab to reproduce?

For jax: https://colab.research.google.com/drive/1MziZSUWEuseaQ6DL_6ykaY9jDk4I2WpB?usp=sharing
For pytotch: https://colab.research.google.com/drive/1FBDxozi6YzzlUNjgz6seKo-xQxbs06JB?usp=sharing

Both the Colabs show the problem with validation_split.

[fchollet]

Thanks for the report. It looks like we only support np arrays and tf tensors for validation_split. This can be fixed easily, actually. Let me just do that in Keras.

[fchollet]

Done. You can retry after building Keras from sources.

[sitamgithub-MSIT]

Done. You can retry after building Keras from sources.

I tried, and the problem of validation split is solved, but errors are still there. For pytorch, TypeError: can't convert cuda:0 device type tensor to numpy. Use Tensor.cpu() to copy the tensor to host memory first. For jax, AttributeError: 'ArrayImpl' object has no attribute 'numpy'

You can check the notebooks for errors.

[fchollet]

Just replace .numpy() with ops.convert_to_numpy which should work with any tensor.

[sitamgithub-MSIT]

Just replace .numpy() with ops.convert_to_numpy which should work with any tensor.

Thanks, it helped the Jax backend. But pytorch is still giving the error TypeError: can't convert cuda:0 device type tensor to numpy. Use Tensor.cpu() to copy the tensor to host memory first.

[sitamgithub-MSIT]

Just replace .numpy() with ops.convert_to_numpy which should work with any tensor.

Thanks, it helped the Jax backend. But pytorch is still giving the error TypeError: can't convert cuda:0 device type tensor to numpy. Use Tensor.cpu() to copy the tensor to host memory first.

I looked over the code again and think the JacardScoreCallback is the cause. Although I attempted, I kept receiving the same error. The only thing causing issues is the torch backend. So, what ought to I do with this PR? Should I point out that the PR currently supports both Jax and TensorFlow backends?

cc: @fchollet

[fchollet]

What's the complete stack trace?