Question

how to calculate standard deviation in python without any packages and functions except len(). And ensure the outcome is same as the output from r function sd().

Answer 1

Answer

Here is your python script ,if you have any doubt please comment, i am here to help you.

Here we know that, we can calculate the standard deviation as follows.

So here i will take one population [32,111,138,28,59,77,97], this standard deviation is 37.84501153334721.

So here i implemented the code for finding standard deviation without any package in python.

Here is the code

data = [32,111,138,28,59,77,97]  #list of population 
sum=0  #sum initially zero
length=len(data) #finding the length of population 
for i in data:
    sum=sum+i      #total sum of the population
mean=sum/length   #mean=total_sum/number of items
variance=0
for i in data:
    variance=variance+((i-mean)**2/length) #finding variance
standard_deviation=variance**(1/2)  #square root of the variance is SD.
print(str(standard_deviation))

output

Any doubt please comment ,

Thanks in advance