simple numpy

Author: alisx

taiyangxue/README.md

@@ -5,6 +5,8 @@
 - [pythonexcel](https://github.com/JustDoPython/python-examples/tree/master/taiyangxue/pythonxlsx) ：Excel 神器 OpenPyXl
 - [recursion](https://github.com/JustDoPython/python-examples/tree/master/taiyangxue/recursion) ：不会编程的程序员不用懂递归
 - [busclock](https://github.com/JustDoPython/python-examples/tree/master/taiyangxue/busclock) : 公交闹钟 ———— 再也不用白等车了
+- [diffusionsimulator](https://github.com/JustDoPython/python-examples/tree/master/taiyangxue/diffusionsimulator) : python 告诉你疫情多可怕
+- [simplenumpy](https://github.com/JustDoPython/python-examples/tree/master/taiyangxue/simplenumpy) : 干掉公式 —— numpy 就要这样学
 
 ---
 

taiyangxue/simplenumpy/app.py

@@ -0,0 +1,38 @@
+import numpy as np
+
+m = np.array([(1,2,3),(2,3,4),(3,4,5)])
+
+print(m**2)
+
+n = np.array([(1,2),(2,3),(3,4)])
+
+print(m.dot(n))
+
+
+# 求和
+print(m.sum())
+# 连乘
+print(m.prod())
+
+# 均值
+
+x = np.array([1,2,3,4,5,6,7,8])
+
+print((1/x.size)*x.sum())
+print(x.sum()/x.size)
+
+# 实现 Frobenius 范数
+print(np.sqrt((m**2).sum()))
+
+# 样本方差
+print(np.sqrt(((x-(x.sum()/x.size))**2).sum()/(x.size-1)))
+print(np.sqrt(((x-np.mean(x))**2).sum()/(x.size-1)))
+# 标准差
+print(np.sqrt(((x-np.mean(x))**2).sum()/x.size))
+print(np.std(x))
+
+# 欧拉距离
+a = np.array([1,2,3,4,5,6])
+b = np.array([2,3,4,5,6,7])
+print(np.sqrt(((a-b)**2).sum()))
+print(np.linalg.norm(a-b))