Using val_loss or val_accuracy with Predefined Validation

[Yosafat1997]

Dear devs,
I want to use tune-sklearn with my predefined dataset in Keras CNN model. I using similar pattern like GridSearchCV but instead rely on loss and accuracy, i want to use loss or accuracy from validation set and make my code like this:

...
        filepath="/content/gdrive/MyDrive/Paper Reproduce/weights-improvement-{epoch:02d}-{accuracy:.2f}.hdf5"
        checkpoint = ModelCheckpoint(filepath, monitor='loss', verbose=1, save_best_only=True, mode='min')
        early_stopping = EarlyStopping(monitor='loss', mode='min')
        callbacks_list = [checkpoint,early_stopping]
        model = KerasClassifier(build_fn=GetModel,verbose=1)
        pds = PredefinedSplit(test_fold = folding)
        grid = TuneGridSearchCV(estimator=model, param_grid=para, n_jobs=1, cv=pds, refit=True)
        grid_result = grid.fit(tX, tY, callbacks = callbacks_list)
        print("Best: %f using %s" % (grid_result.best_score_, grid_result.best_params_))
        good_params = grid_result.best_params_
        print(types(good_params),' ',good_params)
        model_test = GetModel(dropout_rate=grid_result.best_params_['dropout_rate'],
                         feature_len=grid_result.best_params_['feature_len'],
                         wconv=grid_result.best_params_['wconv'],
                         epc=grid_result.best_params_['epc'])
        test_seq(start_sddb,start_normal,test_dt,model_test)
...

And define my predefined validation set like this:

def folding_maker(train,valid):
    t = [train,valid]
    t = pd.concat(t)
    tY = t.pop('CLASS').to_numpy()
    tY = to_categorical(tY)
    t = t.drop(columns=['RECORD_NAME','Minute']).to_numpy()
    t = np.expand_dims(t,axis=-1)
    folded = [-1 if x in train.index else 0 for x in valid.index]
    return t,tY,folded

however when i change the monitor to val_loss it gives me error:

WARNING:tensorflow:Early stopping conditioned on metric `val_loss` which is not available. Available metrics are: loss,accuracy

and when i set it to loss, it works, but the updated value always reseted to -inf following by tracing error:

Epoch 00001: loss improved from inf to 0.56859, saving model to XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
WARNING:tensorflow:6 out of the last 11 calls to <function Model.make_test_function.<locals>.test_function at 0x7f8fa00df6a8> triggered tf.function retracing. Tracing is expensive and the excessive number of tracings could be due to (1) creating @tf.function repeatedly in a loop, (2) passing tensors with different shapes, (3) passing Python objects instead of tensors. For (1), please define your @tf.function outside of the loop. For (2), @tf.function has experimental_relax_shapes=True option that relaxes argument shapes that can avoid unnecessary retracing. For (3), please refer to https://www.tensorflow.org/guide/function#controlling_retracing and https://www.tensorflow.org/api_docs/python/tf/function for  more details.
2/2 [==============================] - 0s 69ms/step - loss: 0.0000e+00 - accuracy: 1.0000

The `start_trial` operation took 2.656 s, which may be a performance bottleneck.

5/5 [==============================] - 2s 239ms/step - loss: 0.9378 - accuracy: 0.7908

Epoch 00001: loss improved from inf to 0.47824, saving model to XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
WARNING:tensorflow:6 out of the last 11 calls to <function Model.make_test_function.<locals>.test_function at 0x7f9176998bf8> triggered tf.function retracing. Tracing is expensive and the excessive number of tracings could be due to (1) creating @tf.function repeatedly in a loop, (2) passing tensors with different shapes, (3) passing Python objects instead of tensors. For (1), please define your @tf.function outside of the loop. For (2), @tf.function has experimental_relax_shapes=True option that relaxes argument shapes that can avoid unnecessary retracing. For (3), please refer to https://www.tensorflow.org/guide/function#controlling_retracing and https://www.tensorflow.org/api_docs/python/tf/function for  more details.
2/2 [==============================] - 0s 58ms/step - loss: 0.0000e+00 - accuracy: 1.0000

The `start_trial` operation took 2.662 s, which may be a performance bottleneck.

My validation data consist of 3 record which contain 30 data for each class (A and B). so by two class it must be 60 data for validation.

[richardliaw]

@Yosafat1997 does it work if you do sklearn.model_selection.GridSearch instead?