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Python实现Keras搭建神经网络训练分类模型教程

程序员文章站 2022-07-02 20:52:35
我就废话不多说了,大家还是直接看代码吧~注释讲解版:# classifier exampleimport numpy as np# for reproducibilitynp.random.seed(...

我就废话不多说了,大家还是直接看代码吧~

注释讲解版:

# classifier example

import numpy as np
# for reproducibility
np.random.seed(1337)
# from keras.datasets import mnist
from keras.utils import np_utils
from keras.models import sequential
from keras.layers import dense, activation
from keras.optimizers import rmsprop

# 程序中用到的数据是经典的手写体识别mnist数据集
# download the mnist to the path if it is the first time to be called
# x shape (60,000 28x28), y
# (x_train, y_train), (x_test, y_test) = mnist.load_data()
# 下载minst.npz:
# 链接: https://pan.baidu.com/s/1b2ppkdodzdjxivgmyooqsa
# 提取码: y5ir
# 将下载好的minst.npz放到当前目录下
path='./mnist.npz'
f = np.load(path)
x_train, y_train = f['x_train'], f['y_train']
x_test, y_test = f['x_test'], f['y_test']
f.close()

# data pre-processing
# 数据预处理
# normalize
# x shape (60,000 28x28),表示输入数据 x 是个三维的数据
# 可以理解为 60000行数据,每一行是一张28 x 28 的灰度图片
# x_train.reshape(x_train.shape[0], -1)表示:只保留第一维,其余的纬度,不管多少纬度,重新排列为一维
# 参数-1就是不知道行数或者列数多少的情况下使用的参数
# 所以先确定除了参数-1之外的其他参数,然后通过(总参数的计算) / (确定除了参数-1之外的其他参数) = 该位置应该是多少的参数
# 这里用-1是偷懒的做法,等同于 28*28
# reshape后的数据是:共60000行,每一行是784个数据点(feature)
# 输入的 x 变成 60,000*784 的数据,然后除以 255 进行标准化
# 因为每个像素都是在 0 到 255 之间的,标准化之后就变成了 0 到 1 之间
x_train = x_train.reshape(x_train.shape[0], -1) / 255
x_test = x_test.reshape(x_test.shape[0], -1) / 255
# 分类标签编码
# 将y转化为one-hot vector
y_train = np_utils.to_categorical(y_train, num_classes = 10)
y_test = np_utils.to_categorical(y_test, num_classes = 10)

# another way to build your neural net
# 建立神经网络
# 应用了2层的神经网络,前一层的激活函数用的是relu,后一层的激活函数用的是softmax
#32是输出的维数
model = sequential([
  dense(32, input_dim=784),
  activation('relu'),
  dense(10),
  activation('softmax')
])

# another way to define your optimizer
# 优化函数
# 优化算法用的是rmsprop
rmsprop = rmsprop(lr=0.001, rho=0.9, epsilon=1e-08, decay=0.0)

# we add metrics to get more results you want to see
# 不自己定义,直接用内置的优化器也行,optimizer='rmsprop'
#激活模型:接下来用 model.compile 激励神经网络
model.compile(
  optimizer=rmsprop,
  loss='categorical_crossentropy',
  metrics=['accuracy']
)

print('training------------')
# another way to train the model
# 训练模型
# 上一个程序是用train_on_batch 一批一批的训练 x_train, y_train
# 默认的返回值是 cost,每100步输出一下结果
# 输出的样式与上一个程序的有所不同,感觉用model.fit()更清晰明了
# 上一个程序是python实现keras搭建神经网络训练回归模型:
# https://blog.csdn.net/weixin_45798684/article/details/106503685
model.fit(x_train, y_train, nb_epoch=2, batch_size=32)

print('\ntesting------------')
# evaluate the model with the metrics we defined earlier
# 测试
loss, accuracy = model.evaluate(x_test, y_test)

print('test loss:', loss)
print('test accuracy:', accuracy)

运行结果:

using tensorflow backend.

training------------

epoch 1/2

  32/60000 [..............................] - eta: 5:03 - loss: 2.4464 - accuracy: 0.0625
 864/60000 [..............................] - eta: 14s - loss: 1.8023 - accuracy: 0.4850 
 1696/60000 [..............................] - eta: 9s - loss: 1.5119 - accuracy: 0.6002 
 2432/60000 [>.............................] - eta: 7s - loss: 1.3151 - accuracy: 0.6637
 3200/60000 [>.............................] - eta: 6s - loss: 1.1663 - accuracy: 0.7056
 3968/60000 [>.............................] - eta: 5s - loss: 1.0533 - accuracy: 0.7344
 4704/60000 [=>............................] - eta: 5s - loss: 0.9696 - accuracy: 0.7564
 5408/60000 [=>............................] - eta: 5s - loss: 0.9162 - accuracy: 0.7681
 6112/60000 [==>...........................] - eta: 5s - loss: 0.8692 - accuracy: 0.7804
 6784/60000 [==>...........................] - eta: 4s - loss: 0.8225 - accuracy: 0.7933
 7424/60000 [==>...........................] - eta: 4s - loss: 0.7871 - accuracy: 0.8021
 8128/60000 [===>..........................] - eta: 4s - loss: 0.7546 - accuracy: 0.8099
 8960/60000 [===>..........................] - eta: 4s - loss: 0.7196 - accuracy: 0.8183
 9568/60000 [===>..........................] - eta: 4s - loss: 0.6987 - accuracy: 0.8230
10144/60000 [====>.........................] - eta: 4s - loss: 0.6812 - accuracy: 0.8262
10784/60000 [====>.........................] - eta: 4s - loss: 0.6640 - accuracy: 0.8297
11456/60000 [====>.........................] - eta: 4s - loss: 0.6462 - accuracy: 0.8329
12128/60000 [=====>........................] - eta: 4s - loss: 0.6297 - accuracy: 0.8366
12704/60000 [=====>........................] - eta: 4s - loss: 0.6156 - accuracy: 0.8405
13408/60000 [=====>........................] - eta: 3s - loss: 0.6009 - accuracy: 0.8430
14112/60000 [======>.......................] - eta: 3s - loss: 0.5888 - accuracy: 0.8457
14816/60000 [======>.......................] - eta: 3s - loss: 0.5772 - accuracy: 0.8487
15488/60000 [======>.......................] - eta: 3s - loss: 0.5685 - accuracy: 0.8503
16192/60000 [=======>......................] - eta: 3s - loss: 0.5576 - accuracy: 0.8534
16896/60000 [=======>......................] - eta: 3s - loss: 0.5477 - accuracy: 0.8555
17600/60000 [=======>......................] - eta: 3s - loss: 0.5380 - accuracy: 0.8576
18240/60000 [========>.....................] - eta: 3s - loss: 0.5279 - accuracy: 0.8600
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20416/60000 [=========>....................] - eta: 3s - loss: 0.5046 - accuracy: 0.8654
21088/60000 [=========>....................] - eta: 3s - loss: 0.4992 - accuracy: 0.8669
21792/60000 [=========>....................] - eta: 3s - loss: 0.4932 - accuracy: 0.8684
22432/60000 [==========>...................] - eta: 3s - loss: 0.4893 - accuracy: 0.8693
23072/60000 [==========>...................] - eta: 2s - loss: 0.4845 - accuracy: 0.8703
23648/60000 [==========>...................] - eta: 2s - loss: 0.4800 - accuracy: 0.8712
24096/60000 [===========>..................] - eta: 2s - loss: 0.4776 - accuracy: 0.8718
24576/60000 [===========>..................] - eta: 2s - loss: 0.4733 - accuracy: 0.8728
25056/60000 [===========>..................] - eta: 2s - loss: 0.4696 - accuracy: 0.8736
25568/60000 [===========>..................] - eta: 2s - loss: 0.4658 - accuracy: 0.8745
26080/60000 [============>.................] - eta: 2s - loss: 0.4623 - accuracy: 0.8753
26592/60000 [============>.................] - eta: 2s - loss: 0.4600 - accuracy: 0.8756
27072/60000 [============>.................] - eta: 2s - loss: 0.4566 - accuracy: 0.8763
27584/60000 [============>.................] - eta: 2s - loss: 0.4532 - accuracy: 0.8771
28032/60000 [=============>................] - eta: 2s - loss: 0.4513 - accuracy: 0.8775
28512/60000 [=============>................] - eta: 2s - loss: 0.4477 - accuracy: 0.8784
28992/60000 [=============>................] - eta: 2s - loss: 0.4464 - accuracy: 0.8786
29472/60000 [=============>................] - eta: 2s - loss: 0.4439 - accuracy: 0.8791
29952/60000 [=============>................] - eta: 2s - loss: 0.4404 - accuracy: 0.8800
30464/60000 [==============>...............] - eta: 2s - loss: 0.4375 - accuracy: 0.8807
30784/60000 [==============>...............] - eta: 2s - loss: 0.4349 - accuracy: 0.8813
31296/60000 [==============>...............] - eta: 2s - loss: 0.4321 - accuracy: 0.8820
31808/60000 [==============>...............] - eta: 2s - loss: 0.4301 - accuracy: 0.8827
32256/60000 [===============>..............] - eta: 2s - loss: 0.4279 - accuracy: 0.8832
32736/60000 [===============>..............] - eta: 2s - loss: 0.4258 - accuracy: 0.8838
33280/60000 [===============>..............] - eta: 2s - loss: 0.4228 - accuracy: 0.8844
33920/60000 [===============>..............] - eta: 2s - loss: 0.4195 - accuracy: 0.8849
34560/60000 [================>.............] - eta: 2s - loss: 0.4179 - accuracy: 0.8852
35104/60000 [================>.............] - eta: 2s - loss: 0.4165 - accuracy: 0.8854
35680/60000 [================>.............] - eta: 2s - loss: 0.4139 - accuracy: 0.8860
36288/60000 [=================>............] - eta: 2s - loss: 0.4111 - accuracy: 0.8870
36928/60000 [=================>............] - eta: 2s - loss: 0.4088 - accuracy: 0.8874
37504/60000 [=================>............] - eta: 2s - loss: 0.4070 - accuracy: 0.8878
38048/60000 [==================>...........] - eta: 1s - loss: 0.4052 - accuracy: 0.8882
38656/60000 [==================>...........] - eta: 1s - loss: 0.4031 - accuracy: 0.8888
39264/60000 [==================>...........] - eta: 1s - loss: 0.4007 - accuracy: 0.8894
39840/60000 [==================>...........] - eta: 1s - loss: 0.3997 - accuracy: 0.8896
40416/60000 [===================>..........] - eta: 1s - loss: 0.3978 - accuracy: 0.8901
40960/60000 [===================>..........] - eta: 1s - loss: 0.3958 - accuracy: 0.8906
41504/60000 [===================>..........] - eta: 1s - loss: 0.3942 - accuracy: 0.8911
42016/60000 [====================>.........] - eta: 1s - loss: 0.3928 - accuracy: 0.8915
42592/60000 [====================>.........] - eta: 1s - loss: 0.3908 - accuracy: 0.8920
43168/60000 [====================>.........] - eta: 1s - loss: 0.3889 - accuracy: 0.8924
43744/60000 [====================>.........] - eta: 1s - loss: 0.3868 - accuracy: 0.8931
44288/60000 [=====================>........] - eta: 1s - loss: 0.3864 - accuracy: 0.8931
44832/60000 [=====================>........] - eta: 1s - loss: 0.3842 - accuracy: 0.8938
45408/60000 [=====================>........] - eta: 1s - loss: 0.3822 - accuracy: 0.8944
45984/60000 [=====================>........] - eta: 1s - loss: 0.3804 - accuracy: 0.8949
46560/60000 [======================>.......] - eta: 1s - loss: 0.3786 - accuracy: 0.8953
47168/60000 [======================>.......] - eta: 1s - loss: 0.3767 - accuracy: 0.8958
47808/60000 [======================>.......] - eta: 1s - loss: 0.3744 - accuracy: 0.8963
48416/60000 [=======================>......] - eta: 1s - loss: 0.3732 - accuracy: 0.8966
48928/60000 [=======================>......] - eta: 0s - loss: 0.3714 - accuracy: 0.8971
49440/60000 [=======================>......] - eta: 0s - loss: 0.3701 - accuracy: 0.8974
50048/60000 [========================>.....] - eta: 0s - loss: 0.3678 - accuracy: 0.8979
50688/60000 [========================>.....] - eta: 0s - loss: 0.3669 - accuracy: 0.8983
51264/60000 [========================>.....] - eta: 0s - loss: 0.3654 - accuracy: 0.8988
51872/60000 [========================>.....] - eta: 0s - loss: 0.3636 - accuracy: 0.8992
52608/60000 [=========================>....] - eta: 0s - loss: 0.3618 - accuracy: 0.8997
53376/60000 [=========================>....] - eta: 0s - loss: 0.3599 - accuracy: 0.9003
54048/60000 [==========================>...] - eta: 0s - loss: 0.3583 - accuracy: 0.9006
54560/60000 [==========================>...] - eta: 0s - loss: 0.3568 - accuracy: 0.9010
55296/60000 [==========================>...] - eta: 0s - loss: 0.3548 - accuracy: 0.9016
56064/60000 [===========================>..] - eta: 0s - loss: 0.3526 - accuracy: 0.9021
56736/60000 [===========================>..] - eta: 0s - loss: 0.3514 - accuracy: 0.9026
57376/60000 [===========================>..] - eta: 0s - loss: 0.3499 - accuracy: 0.9029
58112/60000 [============================>.] - eta: 0s - loss: 0.3482 - accuracy: 0.9033
58880/60000 [============================>.] - eta: 0s - loss: 0.3459 - accuracy: 0.9039
59584/60000 [============================>.] - eta: 0s - loss: 0.3444 - accuracy: 0.9043
60000/60000 [==============================] - 5s 87us/step - loss: 0.3435 - accuracy: 0.9046

epoch 2/2

  32/60000 [..............................] - eta: 11s - loss: 0.0655 - accuracy: 1.0000
 736/60000 [..............................] - eta: 4s - loss: 0.2135 - accuracy: 0.9389 
 1408/60000 [..............................] - eta: 4s - loss: 0.2217 - accuracy: 0.9361
 1984/60000 [..............................] - eta: 4s - loss: 0.2316 - accuracy: 0.9390
 2432/60000 [>.............................] - eta: 4s - loss: 0.2280 - accuracy: 0.9379
 3040/60000 [>.............................] - eta: 4s - loss: 0.2374 - accuracy: 0.9368
 3808/60000 [>.............................] - eta: 4s - loss: 0.2251 - accuracy: 0.9386
 4576/60000 [=>............................] - eta: 4s - loss: 0.2225 - accuracy: 0.9379
 5216/60000 [=>............................] - eta: 4s - loss: 0.2208 - accuracy: 0.9377
 5920/60000 [=>............................] - eta: 4s - loss: 0.2173 - accuracy: 0.9383
 6656/60000 [==>...........................] - eta: 4s - loss: 0.2217 - accuracy: 0.9370
 7392/60000 [==>...........................] - eta: 4s - loss: 0.2224 - accuracy: 0.9360
 8096/60000 [===>..........................] - eta: 4s - loss: 0.2234 - accuracy: 0.9363
 8800/60000 [===>..........................] - eta: 3s - loss: 0.2235 - accuracy: 0.9358
 9408/60000 [===>..........................] - eta: 3s - loss: 0.2196 - accuracy: 0.9365
10016/60000 [====>.........................] - eta: 3s - loss: 0.2207 - accuracy: 0.9363
10592/60000 [====>.........................] - eta: 3s - loss: 0.2183 - accuracy: 0.9369
11168/60000 [====>.........................] - eta: 3s - loss: 0.2177 - accuracy: 0.9377
11776/60000 [====>.........................] - eta: 3s - loss: 0.2154 - accuracy: 0.9385
12544/60000 [=====>........................] - eta: 3s - loss: 0.2152 - accuracy: 0.9393
13216/60000 [=====>........................] - eta: 3s - loss: 0.2163 - accuracy: 0.9390
13920/60000 [=====>........................] - eta: 3s - loss: 0.2155 - accuracy: 0.9391
14624/60000 [======>.......................] - eta: 3s - loss: 0.2150 - accuracy: 0.9391
15424/60000 [======>.......................] - eta: 3s - loss: 0.2143 - accuracy: 0.9398
16032/60000 [=======>......................] - eta: 3s - loss: 0.2122 - accuracy: 0.9405
16672/60000 [=======>......................] - eta: 3s - loss: 0.2096 - accuracy: 0.9409
17344/60000 [=======>......................] - eta: 3s - loss: 0.2091 - accuracy: 0.9411
18112/60000 [========>.....................] - eta: 3s - loss: 0.2086 - accuracy: 0.9416
18784/60000 [========>.....................] - eta: 3s - loss: 0.2084 - accuracy: 0.9418
19392/60000 [========>.....................] - eta: 3s - loss: 0.2076 - accuracy: 0.9418
20000/60000 [=========>....................] - eta: 3s - loss: 0.2067 - accuracy: 0.9421
20608/60000 [=========>....................] - eta: 3s - loss: 0.2071 - accuracy: 0.9419
21184/60000 [=========>....................] - eta: 3s - loss: 0.2056 - accuracy: 0.9423
21856/60000 [=========>....................] - eta: 3s - loss: 0.2063 - accuracy: 0.9419
22624/60000 [==========>...................] - eta: 2s - loss: 0.2059 - accuracy: 0.9421
23328/60000 [==========>...................] - eta: 2s - loss: 0.2056 - accuracy: 0.9422
23936/60000 [==========>...................] - eta: 2s - loss: 0.2051 - accuracy: 0.9423
24512/60000 [===========>..................] - eta: 2s - loss: 0.2041 - accuracy: 0.9424
25248/60000 [===========>..................] - eta: 2s - loss: 0.2036 - accuracy: 0.9426
26016/60000 [============>.................] - eta: 2s - loss: 0.2031 - accuracy: 0.9424
26656/60000 [============>.................] - eta: 2s - loss: 0.2035 - accuracy: 0.9422
27360/60000 [============>.................] - eta: 2s - loss: 0.2050 - accuracy: 0.9417
28128/60000 [=============>................] - eta: 2s - loss: 0.2045 - accuracy: 0.9418
28896/60000 [=============>................] - eta: 2s - loss: 0.2046 - accuracy: 0.9418
29536/60000 [=============>................] - eta: 2s - loss: 0.2052 - accuracy: 0.9417
30208/60000 [==============>...............] - eta: 2s - loss: 0.2050 - accuracy: 0.9417
30848/60000 [==============>...............] - eta: 2s - loss: 0.2046 - accuracy: 0.9419
31552/60000 [==============>...............] - eta: 2s - loss: 0.2037 - accuracy: 0.9421
32224/60000 [===============>..............] - eta: 2s - loss: 0.2043 - accuracy: 0.9420
32928/60000 [===============>..............] - eta: 2s - loss: 0.2041 - accuracy: 0.9420
33632/60000 [===============>..............] - eta: 2s - loss: 0.2035 - accuracy: 0.9422
34272/60000 [================>.............] - eta: 1s - loss: 0.2029 - accuracy: 0.9423
34944/60000 [================>.............] - eta: 1s - loss: 0.2030 - accuracy: 0.9423
35648/60000 [================>.............] - eta: 1s - loss: 0.2027 - accuracy: 0.9422
36384/60000 [=================>............] - eta: 1s - loss: 0.2027 - accuracy: 0.9421
37120/60000 [=================>............] - eta: 1s - loss: 0.2024 - accuracy: 0.9421
37760/60000 [=================>............] - eta: 1s - loss: 0.2013 - accuracy: 0.9424
38464/60000 [==================>...........] - eta: 1s - loss: 0.2011 - accuracy: 0.9424
39200/60000 [==================>...........] - eta: 1s - loss: 0.2000 - accuracy: 0.9426
40000/60000 [===================>..........] - eta: 1s - loss: 0.1990 - accuracy: 0.9428
40672/60000 [===================>..........] - eta: 1s - loss: 0.1986 - accuracy: 0.9430
41344/60000 [===================>..........] - eta: 1s - loss: 0.1982 - accuracy: 0.9432
42112/60000 [====================>.........] - eta: 1s - loss: 0.1981 - accuracy: 0.9432
42848/60000 [====================>.........] - eta: 1s - loss: 0.1977 - accuracy: 0.9433
43552/60000 [====================>.........] - eta: 1s - loss: 0.1970 - accuracy: 0.9435
44256/60000 [=====================>........] - eta: 1s - loss: 0.1972 - accuracy: 0.9436
44992/60000 [=====================>........] - eta: 1s - loss: 0.1972 - accuracy: 0.9437
45664/60000 [=====================>........] - eta: 1s - loss: 0.1966 - accuracy: 0.9438
46176/60000 [======================>.......] - eta: 1s - loss: 0.1968 - accuracy: 0.9437
46752/60000 [======================>.......] - eta: 1s - loss: 0.1969 - accuracy: 0.9438
47488/60000 [======================>.......] - eta: 0s - loss: 0.1965 - accuracy: 0.9439
48256/60000 [=======================>......] - eta: 0s - loss: 0.1965 - accuracy: 0.9438
48896/60000 [=======================>......] - eta: 0s - loss: 0.1963 - accuracy: 0.9436
49568/60000 [=======================>......] - eta: 0s - loss: 0.1962 - accuracy: 0.9438
50304/60000 [========================>.....] - eta: 0s - loss: 0.1965 - accuracy: 0.9437
51072/60000 [========================>.....] - eta: 0s - loss: 0.1967 - accuracy: 0.9437
51744/60000 [========================>.....] - eta: 0s - loss: 0.1961 - accuracy: 0.9439
52480/60000 [=========================>....] - eta: 0s - loss: 0.1957 - accuracy: 0.9439
53248/60000 [=========================>....] - eta: 0s - loss: 0.1959 - accuracy: 0.9438
54016/60000 [==========================>...] - eta: 0s - loss: 0.1963 - accuracy: 0.9437
54592/60000 [==========================>...] - eta: 0s - loss: 0.1965 - accuracy: 0.9436
55168/60000 [==========================>...] - eta: 0s - loss: 0.1962 - accuracy: 0.9436
55776/60000 [==========================>...] - eta: 0s - loss: 0.1959 - accuracy: 0.9437
56448/60000 [===========================>..] - eta: 0s - loss: 0.1965 - accuracy: 0.9437
57152/60000 [===========================>..] - eta: 0s - loss: 0.1958 - accuracy: 0.9439
57824/60000 [===========================>..] - eta: 0s - loss: 0.1956 - accuracy: 0.9438
58560/60000 [============================>.] - eta: 0s - loss: 0.1951 - accuracy: 0.9440
59360/60000 [============================>.] - eta: 0s - loss: 0.1947 - accuracy: 0.9440
60000/60000 [==============================] - 5s 76us/step - loss: 0.1946 - accuracy: 0.9440

testing------------

  32/10000 [..............................] - eta: 15s
 1248/10000 [==>...........................] - eta: 0s 
 2656/10000 [======>.......................] - eta: 0s
 4064/10000 [===========>..................] - eta: 0s
 5216/10000 [==============>...............] - eta: 0s
 6464/10000 [==================>...........] - eta: 0s
 7744/10000 [======================>.......] - eta: 0s
 9056/10000 [==========================>...] - eta: 0s
 9984/10000 [============================>.] - eta: 0s
10000/10000 [==============================] - 0s 47us/step
test loss: 0.17407772153392434
test accuracy: 0.9513000249862671

补充知识:keras 搭建简单神经网络:顺序模型+回归问题

多层全连接神经网络

每层神经元个数、神经网络层数、激活函数等可*修改

使用不同的损失函数可适用于其他任务,比如:分类问题

这是keras搭建神经网络模型最基础的方法之一,keras还有其他进阶的方法,官网给出了一些基本使用方法:keras官网

# 这里搭建了一个4层全连接神经网络(不算输入层),传入函数以及函数内部的参数均可*修改
def ann(x, y):
  '''
  x: 输入的训练集数据
  y: 训练集对应的标签
  '''
  
  '''初始化模型'''
  # 首先定义了一个顺序模型作为框架,然后往这个框架里面添加网络层
  # 这是最基础搭建神经网络的方法之一
  model = sequential()
  
  '''开始添加网络层'''
  # dense表示全连接层,第一层需要我们提供输入的维度 input_shape
  # activation表示每层的激活函数,可以传入预定义的激活函数,也可以传入符合接口规则的其他高级激活函数
  model.add(dense(64, input_shape=(x.shape[1],)))
  model.add(activation('sigmoid'))
  
  model.add(dense(256))
  model.add(activation('relu'))
  
  model.add(dense(256))
  model.add(activation('tanh'))
  
  model.add(dense(32))
  model.add(activation('tanh'))
  
  # 输出层,输出的维度大小由具体任务而定
  # 这里是一维输出的回归问题
  model.add(dense(1))
  model.add(activation('linear'))
  
  '''模型编译'''
  # optimizer表示优化器(可*选择),loss表示使用哪一种
  model.compile(optimizer='rmsprop', loss='mean_squared_error')
  # 自定义学习率,也可以使用原始的基础学习率
  reduce_lr = reducelronplateau(monitor='loss', factor=0.1, patience=10, 
                 verbose=0, mode='auto', min_delta=0.001, 
                 cooldown=0, min_lr=0)
  
  '''模型训练'''
  # 这里的模型也可以先从函数返回后,再进行训练
  # epochs表示训练的轮数,batch_size表示每次训练的样本数量(小批量学习),validation_split表示用作验证集的训练数据的比例
  # callbacks表示回调函数的集合,用于模型训练时查看模型的内在状态和统计数据,相应的回调函数方法会在各自的阶段被调用
  # verbose表示输出的详细程度,值越大输出越详细
  model.fit(x, y, epochs=100,
       batch_size=50, validation_split=0.0,
       callbacks=[reduce_lr],
       verbose=0)
  
  # 打印模型结构
  print(model.summary())

  return model

下图是此模型的结构图,其中下划线后面的数字是根据调用次数而定

Python实现Keras搭建神经网络训练分类模型教程

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