我正在学习卷积神经网络,想为MNIST数据创建一个。每当我在CNN中添加卷积层时,就会出现一个错误:
输入0与层conv2d\u 4不兼容:预期ndim=4,发现ndim=5
我曾试图重塑X\列车数据集,但没有成功 我尝试先添加一个展平层,但返回以下错误:
输入0与层conv2d\u 5不兼容:预期ndim=4,发现ndim=2
import keras
from keras.preprocessing.image import ImageDataGenerator
from keras.models import Sequential
from keras.layers import Convolution2D
from keras.layers import Flatten, Dense, Dropout
img_width, img_height = 28, 28
mnist = keras.datasets.mnist
(X_train, Y_train), (X_test, Y_test) = mnist.load_data()
(X_train, y_train), (X_test, y_test) = mnist.load_data()
X_train = keras.utils.normalize(X_train, axis=1) #Normalizes from 0-1 (originally each pixel is valued 0-255)
X_test = keras.utils.normalize(X_test, axis=1) #Normalizes from 0-1 (originally each pixel is valued 0-255)
Y_train = keras.utils.to_categorical(Y_train) #Reshapes to allow ytrain to work with x train
Y_test = keras.utils.to_categorical(Y_test)
from sklearn import preprocessing
lb = preprocessing.LabelBinarizer()
Y_train = lb.fit_transform(Y_train)
Y_test = lb.fit_transform(Y_test)
#Model
model = Sequential()
model.add(Flatten())
model.add(Convolution2D(16, 5, 5, activation='relu', input_shape=(1,img_width, img_height, 1)))
model.add(Dense(128, activation='relu'))
model.add(Dense(128, activation='relu'))
model.add(Dropout(.2))
model.add(Dense(64, activation='relu'))
model.add(Dense(10, activation='softmax'))
model.compile(optimizer = 'adam',
loss='categorical_crossentropy',
metrics=['accuracy'])
model.fit(X_train, Y_train, epochs=3, verbose=2)
val_loss, val_acc = model.evaluate(X_test, Y_test) #Check to see if model fits test
print(val_loss, val_acc)
如果我把卷积层注释掉,它工作得很好(准确率>95%),但我计划在将来制作一个更复杂的需要卷积的神经网络,这是我的出发点
Keras正在寻找一个4维张量,但它得到的ndim是2维张量。 首先确保Conv2D层中的内核大小在括号中
model.add(Convolution2D(32, (3, 3), activation='relu', input_shape=(img_height, img_height, 1)))
其次,您需要重塑X_列,X_测试变量,因为Conv2D层需要张量输入。你知道吗
X_train = X_train.reshape(-1,28, 28, 1) #Reshape for CNN - should work!! X_test = X_test.reshape(-1,28, 28, 1) model.fit(X_train, Y_train, epochs=3, verbose=2)
有关Conv2D的更多信息,可以查看Keras文档here
希望这有帮助。你知道吗
代码中有两个问题。你知道吗
to_categorical
,另一次使用LabelBinarizer
。这里不需要后者,所以只需使用to_categorical
将标签编码为分类的。你知道吗2.-输入的形状不正确,应该是
(28, 28, 1)
。你知道吗此外,还应该在卷积层之后添加
Flatten
层,以便Dense
层正常工作。你知道吗相关问题 更多 >
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