基本运算
函数 | 运算符 | 说明 |
add(a,b) | a+b | 加 |
subtract(a,b) | a-b | 减 |
multiply(a,b) | a*b | 乘 |
divide(a,b) | a/b | 除 |
mod(a,b) | a%b | 求余 |
power(a,b) | a**b | 求幂 |
第一列函数等价于运算符
# -*- coding:utf-8 -*-
import numpy as np
arr1 = np.array([4,6])
arr2 = np.array([2,4])
print('arr1:',arr1)
print('arr2:',arr2)
print("加:")
print("arr1+arr2: " ,arr1+arr2)
print("add函数:" , np.add(arr1,arr2))
print("减:")
print("arr1-arr2: " ,arr1-arr2)
print("subtract函数:" , np.subtract(arr1,arr2))
print("乘:")
print("arr1*arr2: " ,arr1*arr2)
print("multiply函数:" , np.multiply(arr1,arr2))
print("除:")
print("arr1/arr2: " ,arr1/arr2)
print("divide 函数:" , np.divide(arr1,arr2))
print("求余:")
print("arr1%arr2: " ,arr1%arr2)
print("mod 函数:" , np.mod(arr1,arr2))
print("求幂:")
print("arr1**arr2: " ,arr1**arr2)
print("power 函数:" , np.power(arr1,arr2))比较运算
运算符 | 说明 |
> | 大于 |
< | 小于等 |
>= | 大于等于 |
<= | 小于等于 |
== | 等于 |
!= | 不等于 |
# -*- coding:utf-8 -*-
import numpy as np
#一维数组的比较
arr1 = np.array([4,6])
arr2 = np.array([2,4])
print('arr1:',arr1)
print('arr2:',arr2)
print('一维数组的比较')
print("arr1>arr2: " ,arr1>arr2)
print("arr1<arr2: " ,arr1<arr2)
#二维数组的比较
arr1 = np.array([[4,6],[8,9]])
arr2 = np.array([[2,4],[7,10]])
print('arr1:',arr1)
print('arr2:',arr2)
print('二维数组的比较')
print("arr1>arr2:\n " ,arr1>arr2)
print("arr1<arr2: \n" ,arr1<arr2)标量运算
- 向量是一组数，标量是一个数
- 数组的标量运算：将一个数组与一个数进行运算操作
# -*- coding:utf-8 -*-
import numpy as np
arr1 = np.array([4,6,8,10])
print('一维数组的标量运算')
print('加:',arr1+2)
print('减:',arr1-2)
print("乘: " ,arr1*2)
print("除: " ,arr1/2)
arr1 = np.array([[4,6],[8,9]])
print('二维数组的标量运算')
print('加:',arr1+2)
print('减:',arr1-2)
print("乘: " ,arr1*2)
print("除: " ,arr1/2)数学函数
函数 | 说明 |
square() | 求平方 |
abs() | 求绝对值 |
sqrt() | 求平方根 |
around() | 求四舍五入值 |
ceil() | 向上取整 |
floor() | 向下取整 |
reciprocal() | 求倒数 |
sin() | 求正弦值 |
cos() | 求余弦值 |
tan() | 求正切值 |
# -*- coding:utf-8 -*-
import numpy as np
arr1 = np.array([[1,2],[-3,-4]])
print('arr1:\n',arr1)
print('求平方:\n',np.square(arr1))
print('求绝对值:\n',np.abs(arr1))
arr2 = np.array([[1.2,3.5],[3.6,4.4]])
print('arr2:\n',arr2)
print("求四舍五入值:\n " ,np.around(arr2))
arr3 = np.array([2,1.2,2.8,-0.5,-1.9,-2.1])
print('arr3:\n',arr3)
print("向上取整:\n " ,np.ceil(arr3))
print("向下取整:\n " ,np.floor(arr3))学习参考资料：《从0到1Python数据分析》