解释这段代码train, val = data[-(train_size + val_size):-val_size + 1]['data'], data[-val_size:]['data']
时间: 2023-12-27 19:01:53 浏览: 26
这段代码是用来将数据集按照一定比例划分为训练集和验证集的。其中train_size表示训练集样本数量,val_size表示验证集样本数量,data表示原始数据集。代码中的[-(train_size+val_size):-val_size]表示从倒数第train_size+val_size个样本开始,一直到倒数第val_size个样本结束,即为训练集;而[-val_size:]表示从倒数第val_size个样本开始,一直到最后一个样本结束,即为验证集。
相关问题
def get_CIFAR10_data(num_training=5000, num_validation=500, num_test=500): cifar10_dir = r'D:\daima\cifar-10-python\cifar-10-batches-py' X_train, y_train, X_test, y_test = load_CIFAR10(cifar10_dir) print(X_train.shape) mask = range(num_training, num_training + num_validation) X_val = X_train[mask] y_val = y_train[mask] mask = range(num_training) X_train = X_train[mask] y_train = y_train[mask] mask = range(num_test) X_test = X_test[mask] y_test = y_test[mask] mean_image = np.mean(X_train, axis=0) X_train -= mean_image X_val -= mean_image X_test -= mean_image X_train = X_train.transpose(0, 3, 1, 2).copy() X_val = X_val.transpose(0, 3, 1, 2).copy() X_test = X_test.transpose(0, 3, 1, 2).copy() return { 'X_train': X_train, 'y_train': y_train, 'X_val': X_val, 'y_val': y_val, 'X_test': X_test, 'y_test': y_test, }这是一个加载cifar10数据集的函数,如何修改使其能加载mnist数据集
要加载MNIST数据集,可以使用以下代码修改上述函数:
```
import tensorflow as tf
from tensorflow.keras.datasets import mnist
import numpy as np
def get_MNIST_data(num_training=50000, num_validation=10000, num_test=10000):
(X_train, y_train), (X_test, y_test) = mnist.load_data()
X_train = np.expand_dims(X_train, axis=-1)
X_test = np.expand_dims(X_test, axis=-1)
X_train = X_train.astype('float32') / 255
X_test = X_test.astype('float32') / 255
mean_image = np.mean(X_train, axis=0)
X_train -= mean_image
X_test -= mean_image
mask = range(num_training, num_training + num_validation)
X_val = X_train[mask]
y_val = y_train[mask]
mask = range(num_training)
X_train = X_train[mask]
y_train = y_train[mask]
mask = range(num_test)
X_test = X_test[mask]
y_test = y_test[mask]
return {
'X_train': X_train, 'y_train': y_train,
'X_val': X_val, 'y_val': y_val,
'X_test': X_test, 'y_test': y_test,
}
```
此代码使用 TensorFlow 的 MNIST 数据集加载函数,将数据集的维度转换为 (num_samples, height, width, depth) 的形式,并对图像像素值进行归一化。
设置训练和验证集路径 train_vol_path = "data/train/trainvol" train_seg_path = "data/train/trainseg" val_vol_path = "data/val/valvol" val_seg_path = "data/val/valseg" # 定义数据生成器 train_datagen = ImageDataGenerator(rescale=1./255) val_datagen = ImageDataGenerator(rescale=1./255) # 加载训练和验证数据 train_vol = train_datagen.flow_from_directory(train_vol_path, target_size=(256, 256), batch_size=32, class_mode=None) train_seg = train_datagen.flow_from_directory(train_seg_path, target_size=(256, 256), batch_size=32, class_mode=None) val_vol = val_datagen.flow_from_directory(val_vol_path, target_size=(256, 256), batch_size=32, class_mode=None) val_seg = val_datagen.flow_from_directory(val_seg_path, target_size=(256, 256), batch_size=32, class_mode=None) # 合并训练和验证数据 train_generator = zip(train_vol, train_seg) val_generator = zip(val_vol, val_seg) # 定义UNet模型 model = unet() # 编译模型 model.compile(optimizer=Adam(learning_rate=1e-4), loss='binary_crossentropy', metrics=['accuracy'])报错'NoneType' object has no attribute 'compile'怎么改代码
可以尝试将 `class_mode` 参数设置为 `'binary'` 或者其他适合数据集的值,来解决这个问题。修改后的代码如下所示:
```
# 设置训练和验证集路径
train_vol_path = "data/train/trainvol"
train_seg_path = "data/train/trainseg"
val_vol_path = "data/val/valvol"
val_seg_path = "data/val/valseg"
# 定义数据生成器
train_datagen = ImageDataGenerator(rescale=1./255)
val_datagen = ImageDataGenerator(rescale=1./255)
# 加载训练和验证数据
train_vol = train_datagen.flow_from_directory(train_vol_path, target_size=(256, 256), batch_size=32, class_mode='binary')
train_seg = train_datagen.flow_from_directory(train_seg_path, target_size=(256, 256), batch_size=32, class_mode='binary')
val_vol = val_datagen.flow_from_directory(val_vol_path, target_size=(256, 256), batch_size=32, class_mode='binary')
val_seg = val_datagen.flow_from_directory(val_seg_path, target_size=(256, 256), batch_size=32, class_mode='binary')
# 合并训练和验证数据
train_generator = zip(train_vol, train_seg)
val_generator = zip(val_vol, val_seg)
# 定义UNet模型
model = unet()
# 编译模型
model.compile(optimizer=Adam(learning_rate=1e-4), loss='binary_crossentropy', metrics=['accuracy'])
```