data_X = np.transpose(images, (0, 3, 2, 1)) data_Y = np.transpose(images, (0, 3, 2, 1))
时间: 2023-10-11 10:12:16 浏览: 66
这段代码中,np.transpose函数是用来对数组进行转置操作的。其中,第一个参数是需要进行转置的数组,第二个参数是一个元组,用来指定转置后的维度顺序。在这个例子中,对于数组images,第一维是样本数,第二维是通道数,第三维是高度,第四维是宽度。通过将元组设置为(0, 3, 2, 1),表示将原数组的第一维保持不变,将第二维和第四维交换位置,将第三维和第四维交换位置,最终得到的转置后的数组data_X和data_Y的维度顺序是样本数、宽度、高度、通道数,这种顺序在某些机器学习模型中比较常见。
相关问题
data_train = np.transpose(data_train)
As an AI language model, I do not have access to the specific context of your code. However, based on the syntax and conventions of Python, it looks like you are transposing a numpy array called "data_train".
Transposing an array means swapping its rows and columns. In numpy, you can do this by calling the "transpose" method on the array, which returns a new array with the rows and columns swapped.
The "np.transpose" function is a shorthand for calling the "transpose" method on the numpy array. By passing "data_train" as an argument to "np.transpose", you are transposing the array and assigning the result to the same variable "data_train".
This operation can be useful for manipulating data that is organized in rows and columns, such as images or time series data. Transposing can also be used to perform matrix operations, such as matrix multiplication or inversion.
import pickle import numpy as np import os # from scipy.misc import imread def load_CIFAR_batch(filename): with open(filename, 'rb') as f: datadict = pickle.load(f, encoding='bytes') X = datadict[b'data'] Y = datadict[b'labels'] X = X.reshape(10000, 3, 32, 32).transpose(0, 2, 3, 1).astype("float") Y = np.array(Y) return X, Y def load_CIFAR10(ROOT): xs = [] ys = [] for b in range(1, 2): f = os.path.join(ROOT, 'data_batch_%d' % (b,)) X, Y = load_CIFAR_batch(f) xs.append(X) ys.append(Y) Xtr = np.concatenate(xs) Ytr = np.concatenate(ys) del X, Y Xte, Yte = load_CIFAR_batch(os.path.join(ROOT, 'test_batch')) return Xtr, Ytr, Xte, Yte 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, } def load_models(models_dir): models = {} for model_file in os.listdir(models_dir): with open(os.path.join(models_dir, model_file), 'rb') as f: try: models[model_file] = pickle.load(f)['model'] except pickle.UnpicklingError: continue return models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,不使用TensorFlow
可以使用以下代码加载MNIST数据集:
```
import gzip
import os
import pickle
import numpy as np
def load_mnist(path, kind='train'):
labels_path = os.path.join(path, '%s-labels-idx1-ubyte.gz' % kind)
images_path = os.path.join(path, '%s-images-idx3-ubyte.gz' % kind)
with gzip.open(labels_path, 'rb') as lbpath:
labels = np.frombuffer(lbpath.read(), dtype=np.uint8, offset=8)
with gzip.open(images_path, 'rb') as imgpath:
images = np.frombuffer(imgpath.read(), dtype=np.uint8, offset=16).reshape(len(labels), 784)
return images, labels
def get_mnist_data(num_training=5000, num_validation=500, num_test=500):
mnist_dir = r'D:\daima\mnist' # 修改为mnist数据集所在的目录
X_train, y_train = load_mnist(mnist_dir, kind='train')
X_test, y_test = load_mnist(mnist_dir, kind='t10k')
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]
X_train = X_train.astype('float32') / 255
X_val = X_val.astype('float32') / 255
X_test = X_test.astype('float32') / 255
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,
}
```
这个函数将会返回训练集、验证集和测试集的图像和标签。其中,图像是一个形如`(num_samples, 784)`的数组,标签是一个形如`(num_samples,)`的数组。
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