预备知识:
- tf.where()
条件语句真返回A,条件语句假返回B
import tensorflow as tf
a = tf.constant([1, 2, 3, 1, 1])
b = tf.constant([0, 1, 3, 4, 5])
c = tf.where(tf.greater(a, b), a, b)
# 若a>b,返回a对应位置的元素,否则返回b对应位置的元素
print("c:", c)
- np.random.RandomState.rand()
返回一个[0,1)之间的随机数
import numpy as np
rdm = np.random.RandomState(seed=1) # seed=常数每次生成随机数相同
a = rdm.rand() # 返回一个随机标量
b = rdm.rand(2, 3) # 返回维度为2行3列随机数矩阵
print("a:", a)
print("b:", b)
- np.vstack()
将两个属组按垂直方向叠加
import numpy as np
a = np.array([1, 2, 3])
b = np.array([4, 5, 6])
c = np.vstack((a, b))
print(c)
- np.mgrid[] .ravel() np.c_[]
np.mgrid[起始值:结束值:步长,起始值:结束值:步长,…]
x.ravel() 将x变为一维数组 相当于把.前变量拉直
np.c_[] 使返回的间隔数值点配对
np.c_[数组1,数组2,…]
import numpy as np
x, y = np.mgrid[1:3:1, 2:4:0.5]
grid = np.c_[x.ravel(), y.ravel()]
print("x:", x)
print("y:", y)
print('grid:\n', grid)