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keras topN顯示,自編寫程式碼案例

對於使用已經訓練好的模型,比如VGG,RESNET等,keras都自帶了一個keras.applications.imagenet_utils.decode_predictions的方法,有很多限制:

def decode_predictions(preds,top=5):
 """Decodes the prediction of an ImageNet model.

 # Arguments
 preds: Numpy tensor encoding a batch of predictions.
 top: Integer,how many top-guesses to return.

 # Returns
 A list of lists of top class prediction tuples
 `(class_name,class_description,score)`.
 One list of tuples per sample in batch input.

 # Raises
 ValueError: In case of invalid shape of the `pred` array
  (must be 2D).
 """
 global CLASS_INDEX
 if len(preds.shape) != 2 or preds.shape[1] != 1000:
 raise ValueError('`decode_predictions` expects '
    'a batch of predictions '
    '(i.e. a 2D array of shape (samples,1000)). '
    'Found array with shape: ' + str(preds.shape))
 if CLASS_INDEX is None:
 fpath = get_file('imagenet_class_index.json',CLASS_INDEX_PATH,cache_subdir='models',file_hash='c2c37ea517e94d9795004a39431a14cb')
 with open(fpath) as f:
  CLASS_INDEX = json.load(f)
 results = []
 for pred in preds:
 top_indices = pred.argsort()[-top:][::-1]
 result = [tuple(CLASS_INDEX[str(i)]) + (pred[i],) for i in top_indices]
 result.sort(key=lambda x: x[2],reverse=True)
 results.append(result)
 return results

把重要的東西挖出來,然後自己敲,這樣就OK了,下例以MNIST資料集為例:

import keras
from keras.models import Sequential
from keras.layers import Dense
import numpy as np
import tflearn
import tflearn.datasets.mnist as mnist

def decode_predictions_custom(preds,top=5):
 CLASS_CUSTOM = ["0","1","2","3","4","5","6","7","8","9"]
 results = []
 for pred in preds:
 top_indices = pred.argsort()[-top:][::-1]
 result = [tuple(CLASS_CUSTOM[i]) + (pred[i]*100,) for i in top_indices]
 results.append(result)
 return results

x_train,y_train,x_test,y_test = mnist.load_data(one_hot=True)

model = Sequential()
model.add(Dense(units=64,activation='relu',input_dim=784))
model.add(Dense(units=10,activation='softmax'))
model.compile(loss='categorical_crossentropy',optimizer='sgd',metrics=['accuracy'])
model.fit(x_train,epochs=10,batch_size=128)
# score = model.evaluate(x_test,y_test,batch_size=128)
# print(score)
preds = model.predict(x_test[0:1,:])
p = decode_predictions_custom(preds)
for (i,(label,prob)) in enumerate(p[0]):
 print("{}. {}: {:.2f}%".format(i+1,label,prob)) 
# 1. 7: 99.43%
# 2. 9: 0.24%
# 3. 3: 0.23%
# 4. 0: 0.05%
# 5. 2: 0.03%

補充知識:keras簡單的去噪自編碼器程式碼和各種型別自編碼器程式碼

我就廢話不多說了,大家還是直接看程式碼吧~

start = time()
 
from keras.models import Sequential
from keras.layers import Dense,Dropout,Input
from keras.layers import Embedding
from keras.layers import Conv1D,GlobalAveragePooling1D,MaxPooling1D
from keras import layers
from keras.models import Model
 
# Parameters for denoising autoencoder
nb_visible = 120
nb_hidden = 64
batch_size = 16
# Build autoencoder model
input_img = Input(shape=(nb_visible,))
 
encoded = Dense(nb_hidden,activation='relu')(input_img)
decoded = Dense(nb_visible,activation='sigmoid')(encoded)
 
autoencoder = Model(input=input_img,output=decoded)
autoencoder.compile(loss='mean_squared_error',optimizer='adam',metrics=['mae'])
autoencoder.summary()
 
# Train
### 加一個early_stooping
import keras 
 
early_stopping = keras.callbacks.EarlyStopping(
  monitor='val_loss',min_delta=0.0001,patience=5,verbose=0,mode='auto'
)
autoencoder.fit(X_train_np,y_train_np,nb_epoch=50,batch_size=batch_size,shuffle=True,callbacks = [early_stopping],verbose = 1,validation_data=(X_test_np,y_test_np))
# Evaluate
evaluation = autoencoder.evaluate(X_test_np,y_test_np,verbose=1)
print('val_loss: %.6f,val_mean_absolute_error: %.6f' % (evaluation[0],evaluation[1]))
 
end = time()
print('耗時:'+str((end-start)/60))

keras各種自編碼程式碼

以上這篇keras topN顯示,自編寫程式碼案例就是小編分享給大家的全部內容了,希望能給大家一個參考,也希望大家多多支援我們。