1. np.linspace()
np.linspace() 主要用于生成等差数列,相关参数如下:
- start:起始点
- stop:终止点 【包含】
- num : 生成start和stop之间num个等差间隔的元素,默认50,
- endpoint :生成等差间隔为 (stop - start)/num 的元素,默认为True
- retstep:返回一个(array,num)元组,array是结果数组,num是间隔大小,默认False
- dtype: 输出数组的类型。
# np.linspace
list_1 = np.linspace(0, 9)
list_2 = np.linspace(0, 9, num=10)
list_3 = np.linspace(0, 9, num=10, retstep=True)
list_4 = np.linspace(1, 9, num=10, endpoint=False)
print(list_1)
print("------------------------------------")
print(list_2)
print(list_3)
print("------------------------------------")
print(list_4)
输出:
[0. 0.18367347 0.36734694 0.55102041 0.73469388 0.91836735
1.10204082 1.28571429 1.46938776 1.65306122 1.83673469 2.02040816
2.20408163 2.3877551 2.57142857 2.75510204 2.93877551 3.12244898
3.30612245 3.48979592 3.67346939 3.85714286 4.04081633 4.2244898
4.40816327 4.59183673 4.7755102 4.95918367 5.14285714 5.32653061
5.51020408 5.69387755 5.87755102 6.06122449 6.24489796 6.42857143
6.6122449 6.79591837 6.97959184 7.16326531 7.34693878 7.53061224
7.71428571 7.89795918 8.08163265 8.26530612 8.44897959 8.63265306
8.81632653 9. ]
------------------------------------
[0. 1. 2. 3. 4. 5. 6. 7. 8. 9.]
(array([0., 1., 2., 3., 4., 5., 6., 7., 8., 9.]), 1.0)
------------------------------------
[1. 1.8 2.6 3.4 4.2 5. 5.8 6.6 7.4 8.2]
2. np.ceil() ,np.floor()
- np.ceil() 向上取整,
- np.floor()向下取整
a = np.array([1.2, 4.3, 5.6, 7.2, 8.1])
print(np.ceil(a)) # 向上取整,不是四舍五入
print(np.floor(a)) # 向下取整,不是四舍五入
输出:
[2. 5. 6. 8. 9.]
[1. 4. 5. 7. 8.]