numpy和tensor的转换

tensorlfow

numpy转tensor

a = np.zeros((3, 3))
ta = tf.convert_to_tensor(a)
with tf.Session() as sess:
    print(sess.run(ta))

tensor转numpy

import tensorflow as tf
img1 = tf.constant(value=[[[[1],[2],[3],[4]],[[1],[2],[3],[4]],[[1],[2],[3],[4]],[[1],[2],[3],[4]]]],dtype=tf.float32)
img2 = tf.constant(value=[[[[1],[1],[1],[1]],[[1],[1],[1],[1]],[[1],[1],[1],[1]],[[1],[1],[1],[1]]]],dtype=tf.float32)
img = tf.concat(values=[img1,img2],axis=3)
sess=tf.Session()
#sess.run(tf.initialize_all_variables())
sess.run(tf.global_variables_initializer())
print("out1=",type(img))
#转化为numpy数组
#通过.eval函数可以把tensor转化为numpy类数据
img_numpy=img.eval(session=sess)
print("out2=",type(img_numpy))
#转化为tensor
img_tensor= tf.convert_to_tensor(img_numpy)
print("out2=",type(img_tensor))

mxnet

from mxnet import nd
x = nd.ones((2,3))
a = x.asnumpy()
(type(a), a)
nd.array(a)

pytorch

import torch
import numpy as np
np_data = np.arange(6).reshape((2, 3))
torch_data = torch.from_numpy(np_data)
tensor2array = torch_data.numpy()
print(
    '\nnumpy array:', np_data,          # [[0 1 2], [3 4 5]]
    '\ntorch tensor:', torch_data,      #  0  1  2 \n 3  4  5    [torch.LongTensor of size 2x3]
    '\ntensor to array:', tensor2array, # [[0 1 2], [3 4 5]]
)