add numpy lib to calculate standard deviation

P38_data_sd_analysis.py

@@ -1,20 +1,20 @@
 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
 
-import numpy
+import numpy as np
 
 temperature=[31,32,32,31,28,29,31,38,32,31,30,29,30,31,26]
 
 sorted_temp=sorted(temperature)
-mean_temp=numpy.mean(temperature)
+mean_temp=np.mean(temperature)
 
 print ('original temperature are :',temperature)
 
 print ('sorted temperature are :',sorted_temp)
 
 print ('mean of temperature is: ', mean_temp)
 
-print ('median of temperature is: ', numpy.median(temperature))
+print ('median of temperature is: ', np.median(temperature))
 
 print ('\n')
 
@@ -23,18 +23,22 @@
 num_items=len(temperature)
 product=1.
 
+print ('=======method-1 to calculate standard deviation, step by step=======')
 
 for temp in temperature:
     diff=temp-mean_temp
     sqrt_diff=diff**2
     sqrt_diff_list.append(sqrt_diff)
-    average_sqrt_diff=numpy.mean(sqrt_diff_list)
+    average_sqrt_diff=np.mean(sqrt_diff_list)
     product*=temp
 
-standard_deviation = numpy.sqrt(average_sqrt_diff)
+standard_deviation = np.sqrt(average_sqrt_diff)
 geometric_mean = product ** (1./num_items)
 
 print ('Standard Deviation = ',standard_deviation)
-print ('\n')
+
 print ('Geometric Mean = ',geometric_mean)
 
+print ('=======method-2 to calculate standard deviation, using numpy directly =======')
+
+print ('Standard Deviation = ',np.std(temperature))