Machine Learning : Standard Deviation

• Standard Deviation 

It is a number that describes how spread out the values are.

A low standard deviation means that most of the numbers are close to the mean(average). 

A high standard deviation means that values are spread out over a wider range. 

 

You can use std() to get a standard deviation value. 

 

Example 

import numpy

speed = [11, 20, 582, 12]

x = numpy.std(speed)

print(x)

245.83162428784462

 

• Variance 

It is another number that indicates how spread out the values are. If you take the square root of the variance, you can get the std. You can use var() method to find the variance. 

 

Example 

import numpy

speed = [10, 15, 82, 99, 56]

x = numpy.var(speed)

print(x)

1251.44