深度學習模型調參-基於keras的python學習筆記(四)
阿新 • • 發佈:2019-01-14
版權宣告:本文為博主原創文章,未經博主允許不得轉載。 https://blog.csdn.net/weixin_44474718/article/details/86250535
適用於少量資料的實驗是非常有效的方法。
from keras.models import Sequential
from keras.layers import Dense
import numpy as np
from sklearn.model_selection import GridSearchCV
from keras.wrappers.scikit_learn import KerasClassifier
# 構建模型
def create_model(optimizer='adam', init='glorot_uniform'):
# 構建模型
model = Sequential()
model.add(Dense(units=12, kernel_initializer=init, input_dim=8, activation='relu'))
model.add(Dense(units=8, kernel_initializer=init, activation='relu'))
model.add(Dense(units=1, kernel_initializer= init, activation='sigmoid'))
# 編譯模型
model.compile(loss='binary_crossentropy', optimizer=optimizer, metrics=['accuracy'])
return model
seed = 7
# 設定隨機數種子
np.random.seed(seed)
# 匯入資料
dataset = np.loadtxt('pima-indians-diabetes.csv', delimiter=',')
# 分割輸入x和輸出Y
x = dataset[:, 0 : 8]
Y = dataset[ :, 8]
#建立模型 for scikit-learn
model = KerasClassifier(build_fn=create_model, verbose=0)
# 構建需要調參的引數
param_grid = {}
param_grid['optimizer'] = ['rmsprop', 'adam']
param_grid['init'] = ['glorot_uniform', 'normal', 'uniform']
param_grid['epochs'] = [50, 100, 150, 200]
param_grid['batch_size'] = [5, 10, 20]
# 調參
grid = GridSearchCV(estimator=model, param_grid=param_grid)
results = grid.fit(x, Y)
# 輸出結果
print('Best: %f using %s' % (results.best_score_, results.best_params_))
means = results.cv_results_['mean_test_score']
stds = results.cv_results_['std_test_score']
params = results.cv_results_['params']
for mean, std, param in zip(means, stds, params):
print('%f (%f) with: %r' % (mean, std, param))
筆者用了20分鐘!!!而且執行一次不一定能找到最優的引數組合,需要多次重複執行。