https://drive.google.com/file/d/1Za1PIjx3_14hZ3qYyEXmtqiQiHw3Mo_D/view?usp=share_linkWhy does random forest score differ from r2-score since random forest uses r2-score for evaluation?[enter image description here]enter image description here
The reason two score are differing.
rf = RandomForestRegressor(n_estimators= 100, max_depth = 10, max_features='sqrt')
rf.fit(X_train, y_train)
y_pred=rf.predict(X_test)
print(rf.score(X_test,y_test))
print(r2_score(y_pred,y_test))
output:
0.7111716587426178,
0.6246564690587202
Related
I am new in Machine learning, and I want to detect emotions from the face.
Preprocessing: I used equalizeHist to equalizes the histogram of grayscale images (JAFFE database with 213 images), in the goal to normalizes the brightness and increases the contrast of the image.
Feature extraction: I extract features with Gabors filters from images, and I get a matrix of 213x120. I split data: 60% train data and 40% test data, and I normalize it.
Train and test: for training the model, I use SVM classifier with an RBF kernel. With grid-search, I select the best couple C, gamma (using 10-fold cross-validation). Then, I test the performance of the model on the test data (unseen data), and I get 89% accuracy.
The problem is when I want to predict emotion from a new input face, I get a false result.. Is it an overfitting problem?
UPDATE 1: feature extraction
gf = GaborFilter(ksize=(11, 11), freq_nbr=5, or_nbr=8, lambd=4, sigma=8, gamma=5, psi=5*np.pi/6) #Gabor filter with *cv2.getGaborKernel*
data = []
for j in range(len(roi1_images)): # len(roi1_images) = 213
vect1 = feature_extraction_roi_avr(roi1_images[j], gf.kernels) # feature vect from left eye
vect2 = feature_extraction_roi_avr(roi2_images[j], gf.kernels) # feature vect from right eye (40 features)
vect3 = feature_extraction_roi_avr(roi3_images[j], gf.kernels) # feature vect from mouth (40 features)
vect = np.concatenate((vect1, vect2, vect3), axis=None) # feature vect of one face (40 features)
data.append(vect)
data = np.array(data) # Data matrix (213, 120)
UPDATE 2: Learn and test model
clf = GridSearchCV(estimator=SVC(kernel='rbf'), param_grid=svm_parameters, cv=10, n_jobs=-1) # grid search with 10fold cross validation
scaler = StandardScaler()
# Split data
X_train_, X_test_, y_train, y_test = train_test_split(data, data_labels, random_state=0, test_size=0.4, stratify=data_labels)
X_train = scaler.fit_transform(X_train) # Normalize train data
clf.fit(X_train, y_train) # fit SVM model
X_test = scaler.transform(X_test) # Normalize test data
score = clf.score(X_test, y_test) # calculate mean accuracy
print(score) # score accuracy = 0.8953488372093024
UPDATE 3: predict new input
landmarks, gs_image = detect_landmarks(path_image)
roi1_image = extract_roi(gs_image, landmarks, 1) #extract region 1 (eye 1)
roi2_image = extract_roi(gs_image, landmarks, 2) #extract region 2 (eye 2)
roi3_image = extract_roi(gs_image, landmarks, 3) #extract region 3 (eye 3)
vect1 = feature_extraction_roi_avr(roi1_image, gf.kernels)
vect2 = feature_extraction_roi_avr(roi2_image, gf.kernels)
vect3 = feature_extraction_roi_avr(roi3_image, gf.kernels)
vect = np.concatenate((vect1, vect2, vect3), axis=0)
vect = np.reshape(vect, (1,-1))
vect = scaler.transform(vect)
class_ = clf.predict(vect)[0]
print(class_,end=" ")
I am trying to classify 2 classes of images. Though I am getting high train and validation accuracy (0.97) after 10 epochs, my test results are awful (precision 0.48) and the confusion matrix shows the network is predicting the images for the wrong class (attached results).
There are only 2 classes in the dataset, each class has 10,000 image examples (after augmentation). I am using the VGG16 network. The full dataset is split 20% to test set (this split was performed by taking random images from each class therefore it is shuffled). The remaining images are split to 80% train and 20% valid sets (as indicated in the ImageDataGenerator line of the code). So in the end there are:
12,904 Train images belonging to 2 classes
3,224 Valid images belonging to 2 classes
4,032 Test images belonging to 2 classes
This is my code:
def CNN(CNN='VGG16', choice='predict', prediction='./dataset/Test/image.jpg'):
''' Train images using one of several CNNs '''
Train = './dataset/Train'
Tests = './dataset/Test'
shape = (224, 224)
epochs = 10
batches = 16
classes = []
for c in os.listdir(Train): classes.append(c)
IDG = keras.preprocessing.image.ImageDataGenerator(validation_split=0.2)
train = IDG.flow_from_directory(Train, target_size=shape, color_mode='rgb',
classes=classes, batch_size=batches, shuffle=True, subset='training')
valid = IDG.flow_from_directory(Train, target_size=shape, color_mode='rgb',
classes=classes, batch_size=batches, shuffle=True, subset='validation')
tests = IDG.flow_from_directory(Tests, target_size=shape, color_mode='rgb',
classes=classes, batch_size=batches, shuffle=True)
input_shape = train.image_shape
if CNN == 'VGG16' or 'vgg16':
model = VGG16(weights=None, input_shape=input_shape,
classes=len(classes))
elif CNN == 'VGG19' or 'vgg19':
model = VGG19(weights=None, input_shape=input_shape,
classes=len(classes))
elif CNN == 'ResNet50' or 'resnet50':
model = ResNet50(weights=None, input_shape=input_shape,
classes=len(classes))
elif CNN == 'DenseNet201' or 'densenet201':
model = DenseNet201(weights=None, input_shape=input_shape,
classes=len(classes))
model.compile(optimizer=keras.optimizers.SGD(
lr=1e-3,
decay=1e-6,
momentum=0.9,
nesterov=True),
loss='categorical_crossentropy',
metrics=['accuracy'])
Esteps = int(train.samples/train.next()[0].shape[0])
Vsteps = int(valid.samples/valid.next()[0].shape[0])
if choice == 'train':
history= model.fit_generator(train,
steps_per_epoch=Esteps,
epochs=epochs,
validation_data=valid,
validation_steps=Vsteps,
verbose=1)
plt.plot(history.history['loss'])
plt.plot(history.history['val_loss'])
plt.title('Model Loss')
plt.ylabel('Loss')
plt.xlabel('Epoch')
plt.legend(['Train', 'Validation'], loc='upper left')
plt.show()
plt.plot(history.history['acc'])
plt.plot(history.history['val_acc'])
plt.title('Model Accuracy')
plt.ylabel('Accuracy')
plt.xlabel('Epoch')
plt.legend(['Train', 'Validation'], loc='upper left')
plt.show()
Y_pred = model.predict_generator(tests, verbose=1)
y_pred = np.argmax(Y_pred, axis=1)
matrix = confusion_matrix(tests.classes, y_pred)
df_cm = pd.DataFrame(matrix, index=classes, columns=classes)
plt.figure(figsize=(10,7))
sn.heatmap(df_cm, annot=True)
print(classification_report(tests.classes,y_pred,target_names=classes))
model.save_weights('weights.h5')
elif choice == 'predict':
model.load_weights('./weights.h5')
img = image.load_img(prediction, target_size=shape)
im = image.img_to_array(img)
im = np.expand_dims(im, axis=0)
if CNN == 'VGG16' or 'vgg16':
im = keras.applications.vgg16.preprocess_input(im)
prediction = model.predict(im)
print(prediction)
elif CNN == 'VGG19' or 'vgg19':
im = keras.applications.vgg19.preprocess_input(im)
prediction = model.predict(im)
print(prediction)
elif CNN == 'ResNet50' or 'resnet50':
im = keras.applications.resnet50.preprocess_input(im)
prediction = model.predict(im)
print(prediction)
print(keras.applications.resnet50.decode_predictions(prediction))
elif CNN == 'DenseNet201' or 'densenet201':
im = keras.applications.densenet201.preprocess_input(im)
prediction = model.predict(im)
print(prediction)
print(keras.applications.densenet201.decode_predictions(prediction))
CNN(CNN='VGG16', choice='train')
Results:
precision recall f1-score support
Predator 0.49 0.49 0.49 2016
Omnivore 0.49 0.49 0.49 2016
accuracy -- -- 0.49 4032
I suspect that the ImageDataGenerator() is not shuffling the images "before" the train/valid split. If this is the case how can i force the ImageDataGenerator here in Keras to shuffle the dataset before the split?
If shuffling is not the case, how can i solve my issue? what am I doing wrong?
So your model is basically overfitting, which means that it is "memorizing" your training set. I have a few suggestions:
check that your 2 prediction classes are balanced in your training set. I.e. 50-50 split of 0 and 1. For example, if 90% of your training data is labeled 0, then your model will simply predict everything to be 0 and get right in the validation 90% of the time.
if your training data is already balanced, it means that your model isn't generalizing. Perhaps you could try using the pre-trained model instead of custom training every layer of VGG? You can load the pre-trained weights of VGG but do not include top and train only the dense layers.
Use cross validation. Reshuffle the data in each validation and see whether results in the test set improve.
Somehow, the image generator of Keras works well when combined with fit() or fit_generator() function, but fails miserably when combined
with predict_generator() or the predict() function.
When using Plaid-ML Keras back-end for AMD processor, I would rather loop through all test images one-by-one and get the prediction for each image in each iteration.
import os
from PIL import Image
import keras
import numpy
# code for creating dan training model is not included
print("Prediction result:")
dir = "/path/to/test/images"
files = os.listdir(dir)
correct = 0
total = 0
#dictionary to label all animal category class.
classes = {
0:'This is Cat',
1:'This is Dog',
}
for file_name in files:
total += 1
image = Image.open(dir + "/" + file_name).convert('RGB')
image = image.resize((100,100))
image = numpy.expand_dims(image, axis=0)
image = numpy.array(image)
image = image/255
pred = model.predict_classes([image])[0]
animals_category = classes[pred]
if ("cat" in file_name) and ("cat" in sign):
print(correct,". ", file_name, animals_category)
correct+=1
elif ("dog" in file_name) and ("dog" in animals_category):
print(correct,". ", file_name, animals_category)
correct+=1
print("accuracy: ", (correct/total))
I'm trying to predict 'news' data by 'LSTM Many to One' model. I used keras. What should I change in my model to increase accuracy?
Current accuracy is : 55%
number of labels are : 68
data dimensions:
train_seq_x (16254, 499)
encoded_train_y (16254, 68)
test_seq_x (1807, 499)
test_y (1807,)
Model definition:
def train_model(classifier, feature_vector_train, label, feature_vector_valid, is_neural_net):
classifier.fit(feature_vector_train, label,epochs=10,batch_size=32,validation_split=0.05,shuffle=False)
#predict the labels on validation dataset
predictions = classifier.predict(feature_vector_valid)
if is_neural_net:
predictions = predictions.argmax(axis=-1)
return metrics.accuracy_score(predictions, test_y)
def create_rnn_lstm():
input_layer = layers.Input((train_seq_x.shape[1], ))
embedding_layer = layers.Embedding(len(word_index) + 1, 300, weights=[embedding_matrix], trainable=False)(input_layer)
lstm_layer1 = layers.LSTM(128)(embedding_layer)
output_layer2 = layers.Dense(68, activation="softmax")(lstm_layer1)
model = models.Model(inputs=input_layer, outputs=output_layer2)
model.compile(optimizer=optimizers.Adam(), loss='categorical_crossentropy',metrics=['accuracy'])
return model
classifier = create_rnn_lstm()
classifier.summary()
accuracy = train_model(classifier, train_seq_x, encoded_train_y, test_seq_x, is_neural_net=True)
print "LSTM, Word Embeddings", accuracy
I have created h20 random forest model for fraud prediction.now while scoring using predict function for test data. I got below dataframe from predict function output.
Now for 2nd records it predicted 1 but probability of p1 is far less than p0. What's the correct probability scores (p0/1) and classification we can use for my fraud prediction model?
If these are not correct probabilities then calibrated probabilities calculated using parameters(calibrate_model = True) as mentioned below will give correct probability?
nfolds=5
rf1 = h2o.estimators.H2ORandomForestEstimator(
model_id = "rf_df1",
ntrees = 200,
max_depth = 4,
sample_rate = .30,
# stopping_metric="misclassification",
# stopping_rounds = 2,
mtries = 6,
min_rows = 12,
nfolds=3,
distribution = "multinomial",
fold_assignment="Modulo",
keep_cross_validation_predictions=True,
calibrate_model = True,
calibration_frame = calib,
weights_column = "weight",
balance_classes = True
# stopping_tolerance = .005)
)
predict p0 p1
1 0 0.9986012 0.000896514
2 1 0.9985695 0.000448676
3 0 0.9981387 0.000477767
The prediction labels are based on a threshold and the threshold used is generally based on the threshold that maximizes the F1 score. See the following post to learn more on how to interpret the probability results.
Details on how the calibration frame and model work can be found here and here.
I am using the keras model with the following layers to predict a label of input (out of 4 labels)
embedding_layer = keras.layers.Embedding(MAX_NB_WORDS,
EMBEDDING_DIM,
weights=[embedding_matrix],
input_length=MAX_SEQUENCE_LENGTH,
trainable=False)
sequence_input = keras.layers.Input(shape = (MAX_SEQUENCE_LENGTH,),
dtype = 'int32')
embedded_sequences = embedding_layer(sequence_input)
hidden_layer = keras.layers.Dense(50, activation='relu')(embedded_sequences)
flat = keras.layers.Flatten()(hidden_layer)
preds = keras.layers.Dense(4, activation='softmax')(flat)
model = keras.models.Model(sequence_input, preds)
model.compile(loss='categorical_crossentropy', optimizer='rmsprop', metrics=['acc'])
model.fit(X_train, Y_train, batch_size=32, epochs=100)
However, the softmax function returns a number of outputs of 4 (because I have 4 labels)
When I'm using the predict function to get the predicted Y using the same model, I am getting an array of 4 for each X rather than one single label deciding the label for the input.
model.predict(X_test, batch_size = None, verbose = 0, steps = None)
How do I make the output layer of the keras model, or the model.predict function, decide on one single label, rather than output weights for each label?
The following is a common function to sample from a probability vector
def sample(preds, temperature=1.0):
# helper function to sample an index from a probability array
preds = np.asarray(preds).astype('float64')
preds = np.log(preds) / temperature
exp_preds = np.exp(preds)
preds = exp_preds / np.sum(exp_preds)
probas = np.random.multinomial(1, preds, 1)
return np.argmax(probas)
Taken from here.
The temperature parameter decides how much the differences between the probability weights are weightd. A temperature of 1 is considering each weight "as it is", a temperature larger than 1 reduces the differences between the weights, a temperature smaller than 1 increases them.
Here an example using a probability vector on 3 labels:
p = np.array([0.1, 0.7, 0.2]) # The first label has a probability of 10% of being chosen, the second 70%, the third 20%
print(sample(p, 1)) # sample using the input probabilities, unchanged
print(sample(p, 0.1)) # the new vector of probabilities from which to sample is [ 3.54012033e-09, 9.99996371e-01, 3.62508322e-06]
print(sample(p, 10)) # the new vector of probabilities from which to sample is [ 0.30426696, 0.36962778, 0.32610526]
To see the new vector make sample return preds.