I trained a Keras Sequential Model and Loaded the same later. Both the model are giving different accuracy.
I have came across a similar question but was not able solve the problem.
Sample Code :
Loading and Traing the model
model = gensim.models.FastText.load('abc.simple')
X,y = load_data()
Vectors = np.array(vectors(X))
X_train, X_test, y_train, y_test = train_test_split(Vectors, np.array(y),
test_size = 0.3, random_state = 0)
X_train = X_train.reshape(X_train.shape[0],100,max_tokens,1)
X_test = X_test.reshape(X_test.shape[0],100,max_tokens,1)
data for input to our model
print(X_train.shape)
model2 = train()
score = model2.evaluate(X_test, y_test, verbose=0)
print(score)
Training Accuracy is 90%.
Saved the Model
# Saving Model
model_json = model2.to_json()
with open("model_architecture.json", "w") as json_file:
json_file.write(model_json)
model2.save_weights("model_weights.h5")
print("Saved model to disk")
But after I restarted the kernel and just loaded the saved model and runned it on same set of data, accuracy got reduced.
#load json and create model
json_file = open('model_architecture.json', 'r')
loaded_model_json = json_file.read()
json_file.close()
loaded_model = model_from_json(loaded_model_json)
#load weights into new model
loaded_model.load_weights("model_weights.h5")
print("Loaded model from disk")
# evaluate loaded model on test data
loaded_model.compile(loss='binary_crossentropy', optimizer='rmsprop',
metrics=['accuracy'])
score = loaded_model.evaluate(X_test, y_test, verbose=0)
print(score)
Accuracy got reduced to 75% on the same set of data.
How to make it consistent ?
I have tried the following but of no help :
from keras.backend import manual_variable_initialization
manual_variable_initialization(True)
Even , I saved the whole model at once( weights and architecture) but was not able to solve this issue
Not sure, if your issue has been solved but for future comers.
I had exactly the same problem with saving and loading the weights. So on loading the model the accuracy and loss were changed greatly from 68% accuracy to 2 %. In my experiment, I am using Tensorflow as backend with Keras model layers Embedding, LSTM and Dense. My issue got solved by fixing the seed for keras which uses NumPy random generator and since I am using Tensorflow as backend, I also fixed the seed for it.
These are the lines I added at the top of my file where the model is also defined.
from numpy.random import seed
seed(42)# keras seed fixing
import tensorflow as tf
tf.random.set_seed(42)# tensorflow seed fixing
I hope this helps.
For more information have a look at this- https://machinelearningmastery.com/reproducible-results-neural-networks-keras/
I had the same problem due to a silly mistake of mine - after loading the model I had in my data generator the shuffle option (useful for the training) turned to True instead of False. After changing it to False the model predicted as expected. It would be nice if keras could take care of this automatically. This is my critical code part:
pred_generator = pred_datagen.flow_from_directory(
directory='./ims_dir',
target_size=(100, 100),
color_mode="rgb",
batch_size=1,
class_mode="categorical",
shuffle=False,
)
model = load_model(logpath_ms)
pred=model.predict_generator(pred_generator, steps = N, verbose=1)
My code worked when I scaled my dataset before reevaluating the model. I did this treatment before saving the model and had forgotten to repeat this procedure when I opened the model and wanted to evaluate it again. After I did that, the accuracy value appeared as it should \o/
model_saved = keras.models.load_model('tuned_cnn_1D_HAR_example.h5')
trainX, trainy, testX, testy = load_dataset()
trainX, testX = scale_data(trainX, testX, True)
score = model_saved.evaluate(testX, testy, verbose=0)
print("%s: %.2f%%" % (model_saved.metrics_names[1], score[1]*100))
inside of my function scale_data I used StandardScaler()
Related
I'm using a pre trained InceptionV3 on Keras to retrain the model to make a binary image classification (data labeled with 0's and 1's).
I'm reaching about 65% of accuracy on my k-fold validation with never seen data, but the problem is the model is overfitting to soon. I need to improve this average accuracy, and I guess there is something related to this overfitting problem.
Here are the loss values on epochs:
Here is the code. The dataset and label variables are Numpy Arrays.
dataset = joblib.load(path_to_dataset)
labels = joblib.load(path_to_labels)
le = LabelEncoder()
labels = le.fit_transform(labels)
labels = to_categorical(labels, 2)
X_train, X_test, y_train, y_test = sk.train_test_split(dataset, labels, test_size=0.2)
X_train, X_val, y_train, y_val = sk.train_test_split(X_train, y_train, test_size=0.25) # 0.25 x 0.8 = 0.2
X_train = np.array(X_train)
y_train = np.array(y_train)
X_val = np.array(X_val)
y_val = np.array(y_val)
X_test = np.array(X_test)
y_test = np.array(y_test)
aug = ImageDataGenerator(
rotation_range=20,
zoom_range=0.15,
horizontal_flip=True,
fill_mode="nearest")
pre_trained_model = InceptionV3(input_shape = (299, 299, 3),
include_top = False,
weights = 'imagenet')
for layer in pre_trained_model.layers:
layer.trainable = False
x = layers.Flatten()(pre_trained_model.output)
x = layers.Dense(1024, activation = 'relu')(x)
x = layers.Dropout(0.2)(x)
x = layers.Dense(2, activation = 'softmax')(x) #already tried with sigmoid activation, same behavior
model = Model(pre_trained_model.input, x)
model.compile(optimizer = RMSprop(lr = 0.0001),
loss = 'binary_crossentropy',
metrics = ['accuracy']) #Already tried with Adam optimizer, same behavior
es = EarlyStopping(monitor='val_loss', mode='min', verbose=1, patience=100)
mc = ModelCheckpoint('best_model_inception_rmsprop.h5', monitor='val_accuracy', mode='max', verbose=1, save_best_only=True)
history = model.fit(x=aug.flow(X_train, y_train, batch_size=32),
validation_data = (X_val, y_val),
epochs = 100,
callbacks=[es, mc])
The training dataset has 2181 images and validation has 727 images.
Something is wrong, but I can't tell what...
Any thoughts of what can be done to improve it?
One way to avoid overfitting is to use a lot of data. The main reason overfitting happens is because you have a small dataset and you try to learn from it. The algorithm will have greater control over this small dataset and it will make sure it satisfies all the datapoints exactly. But if you have a large number of datapoints, then the algorithm is forced to generalize and come up with a good model that suits most of the points.
Suggestions:
Use a lot of data.
Use less deep network if you have a small number of data samples.
If 2nd satisfies then don't use huge number of epochs - Using many epochs leads is kinda forcing your model to learn that and your model will learn it well but can not generalize.
From your loss graph , i see that the model is generalized at early epoch ( where there is intersection of both the train & val score) so plz try to use the model saved at that epoch ( and not the later epochs which seems to overfit)
Second option what you have is use lot of training samples..
If you have less no. of training samples then use data augmentations
Have you tried following?
Using a higher dropout value
Lower Learning Rate (lr=0.00001 or lr=0.000001 ...)
More data augmentation you can use.
It seems to me your data amount is low. You may use a lower ratio for test and validation (10%, 10%).
I am new to deep learning and doing some classification problems.
I use EarlyStopping and ModelCheckpoint in my callbacks list but when training is starting, the baseline of the model checkpoint is negative infinity and overwrite 'best_model.h5'.
However, 'best_model.h5' already store my last best model. I want to set the baseline of ModelCheckpoint to the performance of my last best model on the data.
Can anyone help me?
es = EarlyStopping(monitor='val_accuracy', mode='max', verbose=1, patience=3)
mc = ModelCheckpoint('best_model.h5', monitor='val_accuracy', mode='max', save_best_only=True, verbose=1)
model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
model.fit(x_train, y_train, validation_data=(x_valid, y_valid), batch_size=400,\
epochs=20, callbacks=[es, mc])
enter image description here
Do this:
mc = ModelCheckpoint('best_model-{epoch:04d}_{val_accuracy:.2f}.h5', monitor='val_accuracy', mode='max', save_best_only=True, verbose=1)
This will save your new best model with epoch number and validation_accuracy without overwriting best_model.h5. This should later help you pick the best models and compare.
I think your problem was you wanted to save the val_acc before the first epoch - Back to the mechanism of a general machine learning problem, I don't think the accuracy value before the first iteration makes sense to a comparison (your model has not been trained on the given dataset). If you do want, you could check the validation loss (val_loss) if possible.
But if you want to save the log of your training process, you don't need to save model for each epoch. You could use the history function as (import matplotlib.pyplot as plt)
results = model.fit(x_train, y_train, validation_data=(x_valid, y_valid), batch_size=400,epochs=20, callbacks=[es, mc])
plt.figure(figsize=(8, 8))
plt.title("Learning curve")
plt.plot(results.history["loss"], label="loss")
plt.plot(results.history["val_loss"], label="val_loss")
plt.xlabel("Epochs")
plt.ylabel("Loss")
plt.legend()
plt.savefig('loss.png')
plt.figure(figsize=(8, 8))
plt.title("Learning curve")
plt.plot(results.history["acc"], label="accuracy")
plt.plot(results.history["val_acc"], label="accuracy")
plt.xlabel("Epochs")
plt.ylabel("Accuracy")
plt.legend()
plt.savefig('acc.png')
I'm currently trying to use sklearn to correlate population stagnation and happiness internationally. I've prepared and cleaned datasets with pandas, but for some reason, any model I try will not train. One of my columns for the data was countries, so I used pandas get_dummies function to account for feeding strings into the models. My shapes for the training and testing variables are as follows: (617, 67),(617,),(151, 67),(151,).
rf_class = RandomForestClassifier(n_estimators=5)
log_class = LogisticRegression()
svm_class = SVC(kernel='rbf', C=1E11, verbose=False)
def run(model, model_name='this model', trainX=trainX, trainY=trainY, testX=testX, testY=testY):
# print(cross_val_score(model, trainX, trainY, scoring='accuracy', cv=10))
accuracy = cross_val_score(model, trainX, trainY,
scoring='accuracy', cv=2).mean() * 100
model.fit(trainX, trainY)
testAccuracy = model.score(testX, testY)
print("Training accuracy of "+model_name+" is: ", accuracy)
print("Testing accuracy of "+model_name+" is: ", testAccuracy*100)
print('\n')
# run(rf_class,'log')
model = log_class
model.fit(trainX,trainY)
perm = PermutationImportance(model, random_state=1).fit(testX, testY)
eli5.show_weights(perm, feature_names=feature_names)
Is my dataset simply too small to train on? Are the dummies too much for the models? Any help that can be offered is greatly appreciated.
I am going to fine-tune InceptionV3 model using my self-defined dataset. Unfortunately, when using model.fit to train, here comes the error below:
ValueError: Error when checking target: expected dense_6 to have shape (4,) but got array with shape (1,)
Firstly, I load my own dataset as training_data which contains a pair of image and corresponding label. Then, I use the code below to convert them into specific array-type(img_new and label_new) so that it's compatible to Keras's inputs of both data and labels.
for img, label in training_data:
img_new[i,:,:,:] = img
label_new[i,:] = label
i=i+1
Second, I fine tune the Inception Model below.
InceptionV3_model=keras.applications.inception_v3.InceptionV3(include_top=False,
weights='imagenet',
input_tensor=None,
input_shape=None,
pooling=None,
classes=1000)
#InceptionV3_model.summary()
# add a global spatial average pooling layer
x = InceptionV3_model.output
x = GlobalAveragePooling2D()(x)
# let's add a fully-connected layer
x = Dense(1024, activation='relu')(x)
# and a logistic layer -- let's say we have 4 classes
predictions = Dense(4, activation='softmax')(x)
# this is the model we will train
model = Model(inputs=InceptionV3_model.input, outputs=predictions)
# Transfer Learning
for layer in model.layers[:311]:
layer.trainable = False
for layer in model.layers[311:]:
layer.trainable = True
from keras.optimizers import SGD
model.compile(optimizer=SGD(lr=0.001, momentum=0.9), loss='categorical_crossentropy')
model.fit(x=X_train, y=y_train, batch_size=3, epochs=3, validation_split=0.2)
model.save_weights('first_try.h5')
Does anyone have ideas of what is wrong while training using model.fit?
Sincerely thanks for your kind help.
The error is caused because my labels r integers, I gotta compile it by sparse_categorical_crossentropy which is set for integer labels instead of categorical_crossentropy which is used for one-hot encoding.
Sincerely thank for the help by #Amir very much. :-)
I am trying to fine-tune pre-trained Inceptionv3 in Keras for a multi-label (17) prediction problem.
Here's the code:
# create the base pre-trained model
base_model = InceptionV3(weights='imagenet', include_top=False)
# add a new top layer
x = base_model.output
predictions = Dense(17, activation='sigmoid')(x)
# this is the model we will train
model = Model(inputs=base_model.input, outputs=predictions)
# we need to recompile the model for these modifications to take effect
# we use SGD with a low learning rate
from keras.optimizers import SGD
model.compile(loss='binary_crossentropy', # We NEED binary here, since categorical_crossentropy l1 norms the output before calculating loss.
optimizer=SGD(lr=0.0001, momentum=0.9))
# Fit the model (Add history so that the history may be saved)
history = model.fit(x_train, y_train,
batch_size=128,
epochs=1,
verbose=1,
callbacks=callbacks_list,
validation_data=(x_valid, y_valid))
But I got into the following error message and had trouble deciphering what it is saying:
ValueError: Error when checking target: expected dense_1 to have 4
dimensions, but got array with shape (1024, 17)
It seems to have something to do with that it doesn't like my one-hot encoding for the labels as target. But how do I get 4 dimensions target?
It turns out that the code copied from https://keras.io/applications/ would not run out-of-the-box.
The following post has helped me:
Keras VGG16 fine tuning
The changes I need to make are the following:
Add in the input shape to the model definition base_model = InceptionV3(weights='imagenet', include_top=False, input_shape=(299,299,3)), and
Add a Flatten() layer to flatten the tensor output:
x = base_model.output
x = Flatten()(x)
predictions = Dense(17, activation='sigmoid')(x)
Then the model works for me!