AttributeError: 'NumpyArrayIterator' object has no attribute 'classes'

Question

I get this error:

I am trying to make a confusion matrix to evaluate the Neural Net I have trained. I am using ImageDatagenerator and datagen.flow functions for before the fit_generator function for training.

For predictions I use the predict_generator function on the test set. All is working fine so far. Issue arrises in the following:

test_generator.reset()
pred = model.predict_generator(test_generator, steps=len(test_generator), verbose=2)

from sklearn.metrics import classification_report, confusion_matrix, cohen_kappa_score

y_pred = np.argmax(pred, axis=1)

print('Confusion Matrix')
print(pd.DataFrame(confusion_matrix(test_generator.classes, y_pred)))

I should be seeing a confusion matrix but instead I see an error. I ran the same code with sample data before I ran on the actual dataset and that did show me the results.

If I understand well, you want to make confusion_matrix of test_generator classes and predicted (y_pred) classes? — FirePower
– FirePower, Commented Oct 30, 2019 at 13:12

FirePower · Accepted Answer · 2019-10-31 10:54:56Z

1

First you need to extract labels from generator and then put them in confusion_matrix function.
To extract labels use x_gen,y_gen = test_generator.next(), just pay attention that labels are one hot encoded.

Example:

test_generator.reset()
pred = model.predict_generator(test_generator, steps=len(test_generator), verbose=2)

from sklearn.metrics import classification_report, confusion_matrix, cohen_kappa_score

y_pred = np.argmax(pred, axis=1)

x_gen,y_gen = test_generator.next()
y_gen = np.argmax(y_gen, axis=1)

print('Confusion Matrix')
print(pd.DataFrame(confusion_matrix(y_gen, y_pred)))

edited Oct 31, 2019 at 10:54

answered Oct 31, 2019 at 9:00

FirePower

4425 silver badges13 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Fauz Over a year ago

That gives me the following error: ValueError: Found input variables with inconsistent numbers of samples: [32, 8871] y_gen should also be 8871.

Collectives™ on Stack Overflow

AttributeError: 'NumpyArrayIterator' object has no attribute 'classes'

1 Answer 1

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related