Задачи по Python и машинному обучению. Страница 27

import numpy as np
x = np.array([[1, 2], [3, 4]])
a = x.flatten()
b = x.ravel()
a[0] = 0
b[1] = 0
print(x.sum())

import numpy as np
x = np.array([[1], [2]])
a = x.ravel()
a[0] = 0
print(x.sum())

import numpy as np
a = np.array([[1, 2], [3, 4], [5, 6]])
b = a.flatten()
print(len(a), len(b))

import numpy as np
a = np.arange(4)
b = a / 0
print(b)

import numpy as np
a = np.linspace(1, 3, 3) ** 3
x = a > 20
y = a < 8
print(x ^ y)

import numpy as np
a = np.array(((0, 1), (2, 3)))
b = a
x = np.sum(a * b)
y = np.sum(a @ b)
z = np.sum(a.dot(b))
print(x == y, y == z)

import numpy as np
x1 = np.linspace(0, 5, 5, endpoint=False)
y1 = np.linspace(0, 5, 5, endpoint=True)
x2 = np.linspace(0, 5, 5, endpoint=False)
y2 = np.linspace(0, 4, 5, endpoint=True)
print(np.sum(x1) == np.sum(y1), np.sum(x2) == np.sum(y2))

import numpy as np
a = np.arange(2)
b = np.arange(1, 2, 1)
print(a == b)

import numpy as np
a = np.array(((1, 0, 1), (0, 1, 0)))
print(a.size)

import numpy as np
a = np.array(((1, 0, 1), (0, 1, 0)))
print(a.ndim)

import numpy as np
a = np.array(((1, 0, 1), (0, 1, 0)))
print(a.shape)

import numpy as np
x = np.fromfunction(lambda i, j: 2 * i * j, (3, 3), dtype=int)
y = np.sum(x[1])
print(y)

def f(i, j):
    return i * j

x = np.fromfunction(f, (3, 3), dtype=int)
y = np.sum(x)
print(y)

import numpy as np
x = np.linspace(0, 5, 5, endpoint=False)
y = np.linspace(0, 5, 5, endpoint=True)
print(x.size - y.size)