Keras layer feature labels - python-3.x

Is keras model layer ferature labels are same to the orginal labels
model.add(Flatten())
model.add(Dense(380,name = 'dense_1'))
model.add(Activation('relu'))
model.add(Dropout(0.1))
model.add(Dense(classes_num ))
model.add(Activation('softmax'))
model.compile(optimizer='rmsprop', loss='categorical_crossentropy',
metrics=['accuracy',mean_pred,recall,precision,fmeasure, matthews_correlation,kullback_leibler_divergence,
binary_crossentropy])
model.summary()
print('model complied!!')
print('starting training....')
history = model.fit(X_train, Y_train, epochs=epochs, batch_size=64,validation_data=(X_test, Y_test))
extract =Model(model.input,[model.get_layer("dense_1").output,model.output])
test_feature,test_labels= extract.predict(X_test)
Is the test_labels and y_test are same or not.If i want to use the layer features what labels i should use

test_label is a decimals that shows probability of membership in each class and it is not same as y_test. if you get index of maximum value in output of softmax layer it shows the class that your network determine according to inputs.

Related

How to add the Count Vectorizer to Simple RNN model?

For my NLP project I used CountVectorizer to Extract Features from a dataset using vectorizer = CountVectorizer(stop_words='english') and all_features = vectorizer.fit_transform(data.Text) and i also wrote a Simple RNN model using keras but I am not sure how to do the padding and the tokeniser step and get the data be trained on the model.
my code for RNN is:
model.add(keras.layers.recurrent.SimpleRNN(units = 1000, activation='relu',
use_bias=True))
model.add(keras.layers.Dense(units=1000, input_dim = 2000, activation='sigmoid'))
model.add(keras.layers.Dense(units=500, input_dim=1000, activation='relu'))
model.add(keras.layers.Dense(units=2, input_dim=500,activation='softmax'))
model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
return model
can someone please give me some advice on this?
Thank you
add ensemble - you don't count vectorize, you use ensemble
https://github.com/dnishimoto/python-deep-learning/blob/master/UFO%20.ipynb
docs=ufo_df["summary"] #text
LABELS=['Egg', 'Cross','Sphere', 'Triangle','Disk','Oval','Rectangle','Teardrop']
#LABELS=['Triangle']
target=ufo_df[LABELS]
#print([len(d) for d in docs])
encoded_docs=[one_hot(d,vocab_size) for d in docs]
#print([np.max(d) for d in encoded_docs])
padded_docs = pad_sequences(encoded_docs, maxlen=max_length, padding='post')
#print([d for d in padded_docs])
model=Sequential()
model.add(Embedding(vocab_size, 8, input_length=max_length))
model.add(Flatten())
model.add(Dense(8, activation='softmax'))
#model.compile(optimizer='adam', loss='categorical_crossentropy', metrics=['accuracy'])
model.compile(optimizer='adam', loss='binary_crossentropy', metrics=['accuracy'])
model.fit(padded_docs, target, epochs=50, verbose=0)

Why does CNN only predict one class

I have a model that needs to detect if a plant is dead or alive. It is only predicting one class, that data is imbalanced, but i have used weights to counter the imbalance.
I have looked at loads of questions about this problem, but none seem to work, apparently this problem occurs when overfitting, so I have used dropout. But the model still only predicts one class.
Heres the model:
model=Sequential()
# Convolutional layer / input layer
model.add(Conv2D(60, 5,5, activation='relu', input_shape=np.shape(X[1])))
model.add(MaxPooling2D(pool_size=(3,3)))
model.add(Dropout(0.8))
model.add(Flatten())
model.add(Dropout(0.7))
model.add(Dense(130, activation='relu'))
model.add(Dropout(0.6))
# Output layer
model.add(Dense(2, activation='softmax'))
model.compile(loss='binary_crossentropy',
optimizer='adam',
metrics=['accuracy'])
model.fit(X, y, epochs=6, batch_size=32, class_weight=class_weight, validation_data=(X_test, y_test))
Usually it should predict both classes with 1: a healthy plant and 0:
an unhealthy plant
Since your problem is a binary classification and your output dimensionality is 2, you should change your activation to softmax.
model.add(Dense(2, activation='softmax'))
However, if you want to keep sigmoid just change your output layer units to 1, this way you will output how likely your input is one of the two classes with only one unit.
model.add(Dense(1, activation='sigmoid'))

Find Most Important Input from a Neural Network

I trained a neural network with 37 Inputs. It has around 85% accuracy. Is it possible for me to find out which Input has the most effect. I tried this code but I cannot figure out how to find most important Input
weights = model.layers[0].get_weights()[0]
biases = model.layers[0].get_weights()[1]
One possible solution is to wrap your model with keras.wrappers.scikit_learn and then use Recursive Feature elimination in scikit-learn:
def create_model():
# create model
model = Sequential()
model.add(Dense(512, activation='relu'))
model.add(Dense(512, activation='relu'))
model.add(Dense(10, activation='softmax'))
# Compile model
model.compile(loss='categorical_crossentropy', optimizer='adam', metrics=['accuracy'])
return model
model = KerasClassifier(build_fn=create_model, epochs=100, batch_size=128, verbose=0)
rfe = RFE(estimator=model, n_features_to_select=1, step=1)
rfe.fit(X, y)
ranking = rfe.ranking_.reshape(digits.images[0].shape)
# Plot pixel ranking
plt.matshow(ranking, cmap=plt.cm.Blues)
plt.colorbar()
plt.title("Ranking of pixels with RFE")
plt.show()
If you need to visualize weights see here.

Input of RNN model layer how it works?

I don't understand input of RNN model. Why it show None before node size every layer. Why it is (None,1) (None,12)
This is my code.
K.clear_session()
model = Sequential()
model.add(Dense(12, input_dim=1, activation='relu'))
model.add(Dropout(0.2))
model.add(Dense(1))
model.compile(loss='mean_squared_error', optimizer='adam')
model.summary()
This is not a RNN, it's just a fully connected network (FC or Dense).
The first dimension of every tensor in a Keras network is the batch_size, which represents the number of "samples" or "examples" you are passing to the model. The value is None because this dimension is not fixed, you can have batches of any size you want.

Keras: shape error when using validation data

Trying to add validation to model.fit, but whenever I do I get an error:
ValueError: Cannot feed value of shape (6, 4, 10) for Tensor 'lstm_input_1:0', which has shape '(32, 4, 10)'
Model:
data_dim = 10
timesteps = 4
batch_size = 32
model = Sequential()
model.add(LSTM(128, batch_input_shape=(batch_size, timesteps, data_dim), return_sequences=True, stateful=True))
model.add(LSTM(64, return_sequences=True, stateful=True))
model.add(LSTM(32, stateful=True))
model.add(Dense(2, activation='softmax'))
sgd = SGD(lr=0.001, momentum=0.0, decay=0.0, nesterov=False)
model.compile(optimizer=sgd, loss='categorical_crossentropy', metrics=['accuracy'])
model.fit(x_train, y_train, nb_epoch=50, batch_size=batch_size, validation_split=0.5)
What could be the error? If I remove validation_split the training works just fine. I've also tried to manually split my training set into two and add it with validation_data=(x_val, y_val) but I got the exact same error.
The issue comes from the fact that you hard code the batch_size value of your inputs. You have fixed it to 32 and then when you try and validate your model, the validation data is sent with a batch of 6 samples, this might be because you don't have enough validation data or maybe because the number of sample isn't a multiple of 32... However, I would let the batch_size free if I was you. Like this:
model.add(LSTM(128, input_shape=(timesteps, data_dim), return_sequences=True, stateful=True))
You specify input_shape instead of batch_input_shape. That way, your network will accept any size of batch, every layer down in the stream of your model are made to adapt to any batch_size if not hardcoded.
I hope this helps :)

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