import numpy as np import pandas as pd from keras.models import Sequential from keras.layers import Dense, Dropout from keras.wrappers.scikit_learn import KerasClassifier from keras.utils import np_utils from sklearn.model_selection import train_test_split, KFold, cross_val_score from sklearn.preprocessing import LabelEncoder from keras.optimizers import SGD from keras.layers import LSTM # load dataset dataframe = pd.read_csv("./data/iris1.csv", header=None) dataset = dataframe.values X = dataset[:, 0:19].astype(float) dummy_y1 = dataset[:, 19] m,n=1682,6 dum_imax=np.zeros((m,n)) # print(type(dum_imax)) for i in range(m): # print(i) # exit() if dummy_y1[i]!=0: dum_imax[i][dummy_y1[i]-1]=1 else: dum_imax[i][5]=1 # print(dum_imax) dummy_y =dum_imax print(dummy_y) print(type(dummy_y[0][0])) def baseline_model(): model = Sequential() model.add(Dense(output_dim=50, input_dim=19, activation='relu')) # model.add(LSTM(128)) model.add(Dropout(0.4)) model.add(Dense(output_dim=6, input_dim=50, activation='softmax')) # Compile model sgd = SGD(lr=0.01, decay=1e-6, momentum=0.9, nesterov=True) # model.compile(loss='categorical_crossentropy', optimizer=sgd) #编译模型。由于我们做的是二元分类,所以我们指定损失函数为binary_crossentropy,以及模式为binary #另外常见的损失函数还有mean_squared_error、categorical_crossentropy等,请阅读帮助文件。 #求解方法我们指定用adam,还有sgd、rmsprop等可选 model.compile(loss='categorical_crossentropy', optimizer=sgd, metrics=['accuracy']) return model estimator = KerasClassifier(build_fn=baseline_model, nb_epoch=40, batch_size=256) print(estimator) # splitting data into training set and test set. If random_state is set to an integer, the split datasets are fixed. X_train, X_test, Y_train, Y_test = train_test_split(X, dummy_y, test_size=0.2, random_state=0)#train_test_split是交叉验证中常用的函数,功能是从样本中随机的按比例选取train data和testdata, print(len(X_train[0])) print(len(Y_train[0])) estimator.fit(X_train, Y_train,nb_epoch = 100)#训练模型,学习一百次 # make predictions print(X_test) pred = estimator.predict(X_test) print(pred) # init_lables = encoder.inverse_transform(pred) # print(init_lables) # inverse numeric variables to initial categorical labels # init_lables = encoder.inverse_transform(pred) # print(init_lables) # k-fold cross-validate # seed = 42 # np.random.seed(seed) ''' n_splits : 默认3,最小为2;K折验证的K值 shuffle : 默认False;shuffle会对数据产生随机搅动(洗牌) random_state :默认None,随机种子 ''' kfold = KFold(n_splits=5, shuffle=True)#定义5折,在对数据进行划分之前,对数据进行随机混洗 results = cross_val_score(estimator, X, dummy_y, cv=kfold)#在数据集上,使用k fold交叉验证,对估计器estimator进行评估。 print("baseline:%.2f%%(%.2f%%)"%(results.mean()*100,results.std()*100))#返回的结果,是10次数据集划分后,每次的评估结果。评估结果包括平均准确率和标准差
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