From d427eaab70fb54fcf22ec41d901f2991404b6e47 Mon Sep 17 00:00:00 2001
From: LiangMa <liang.ma.sh@gmail.com>
Date: Sun, 16 Jun 2019 16:16:38 +0800
Subject: [PATCH] new code for statistic terms study

---
 P122_freinds_analysis_numpy.py | 92 ++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 P122_freinds_analysis_numpy.py

diff --git a/P122_freinds_analysis_numpy.py b/P122_freinds_analysis_numpy.py
new file mode 100644
index 0000000..a2c4bdc
--- /dev/null
+++ b/P122_freinds_analysis_numpy.py
@@ -0,0 +1,92 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+#import random
+import numpy as np
+import pandas as pd
+from matplotlib import pyplot as plt
+
+friends = [109, 1017, 1127, 418, 625, 957, 89, 950, 946, 797, 981, 125, 455, 731, 1640, 485, 1309, 472, 1132, 1773, 906, 531, 742, 621]
+
+happiness = [.8, .6, .3, .6, .6, .4, .8, .5, .4, .3, .3, .6, .2, .8, 1, .6, .2, .7, .5, .3, .1, 0, .3, 1]
+
+
+mean                   =np.mean(friends)
+median                 =np.median(friends)
+max                    =np.max(friends)
+min                    =np.min(friends)
+range_fr               =np.max(friends)-np.min(friends)
+standard_deviation_bias=np.std(friends)
+standard_deviation_nonbias=np.std(friends, ddof=1)
+variance               =np.var(friends)
+covariance             =np.cov(friends)
+
+item_number=len(friends)
+
+#------------------------------#
+
+print ("use the numpy for data processing...\n")
+print ("total ",item_number," items.\n")
+print ("the mean of the friends = ",mean ,"\n")
+
+print ("the median of the friends = ",median ,"\n")
+
+print ("the max of the friends = ",max,"\n")
+
+print ("the min of the friends = ",min,"\n")
+
+print ("the range of the friends = ",range_fr,"\n")
+
+print ("the standard deviation of the friends (bias) = ",standard_deviation_bias,"\n")
+
+print ("the standard deviation of the friends (non-bias) = ",standard_deviation_nonbias,"\n")
+
+print ("the variance of the friends = ",variance,"\n")
+
+print ("calculate the sqrt of variance =", variance**0.5, "\n")
+
+print ("the covariance of the friends = ",covariance,"\n")
+
+print ("calculate the sqrt of covariance =", covariance**0.5, "\n")
+
+y_pos=range(len(friends))
+
+z_scores_list=[]
+for friend in friends:
+    z_temp=(friend-mean)/standard_deviation_bias
+    z_scores_list.append(z_temp)
+
+#------------------------------#
+print ("the plot to show the mean and standard deviation","\n")
+
+print ("the plot to show the Z-Score result","\n")
+
+plt.figure()
+plt.subplot(2, 1, 1)    # (#of row, #of col, index)
+
+plt.bar (y_pos, friends)
+plt.xlabel ("Sample Index")
+plt.ylabel ("Friends number")
+plt.title  ("the chat to show the friends statisic result")
+plt.grid(True)
+
+plt.plot ((0,item_number), (mean,mean), 'b-',label= "mean")          #mean
+plt.plot ((0,item_number), (mean+standard_deviation_nonbias,mean+standard_deviation_nonbias), 'g-', label="mean+std_dev")  #mean+std_dev
+plt.plot ((0,item_number), (mean-standard_deviation_nonbias,mean-standard_deviation_nonbias), 'r-', label="mean-std_dev" )  #mean-std_dev
+
+plt.legend()
+
+plt.subplot(2, 1, 2)
+plt.bar (y_pos, z_scores_list)
+plt.xlabel ("Sample Index")
+plt.ylabel ("Z-Score result")
+plt.title  ("the chat to show the Z-Score")
+plt.grid(True)
+
+plt.plot ((0,item_number), (0,0), 'b-',label= "mean")          #mean
+plt.plot ((0,item_number), (1,1), 'g-', label="mean+1*sigma")  #mean+std_dev
+plt.plot ((0,item_number), (-1, -1), 'r-', label="mean-1*sigma" )  #mean-std_dev
+
+plt.legend()    # this is neccesary for lebel of each line to show.
+
+plt.show()