向量基础实践

1.向量模长计算

import numpy as np
from math import pow,sqrt
"""
1.向量描述
2.模长的计算
3.
"""
a1 = [1,2,3]
a2 = (1,2,3)

a = np.array([3,4])

print(sqrt(a[0]**2 + a[1]**2))

b = np.array([
    [3],
    [4]
])
sum = 0
for v in b:
    sum += pow(v[0],2)
len = sqrt(sum)
print(len)

2.向量加法

import numpy as np
from math import pow,sqrt


a = np.array([3,4])
b = np.array([2,5])
print(a+b)

a1 = np.array([
    [1],
    [2]
])

a2 = np.array([
    [3],
    [4]
])
print(a1+a2)

3.两个向量点乘

import numpy as np
from math import pow,sqrt


a = np.array([3,4])
b = np.array([2,5])

print(a.dot(b))
print(a@b)
print(np.dot(a,b))

4. 三维向量叉乘

import numpy as np
from math import pow,sqrt

xa = 3
ya = 2
za = 7

xb = 2
yb = 4
zb = 6
a = np.array([xa,ya,za])
b = np.array([xb,yb,zb])
# xc = ya*zb -za*yb
# yc = za*xb - xa*zb
# zc = xa*yb - ya * xb
print(np.cross(a,b))