title: Python numpy.random.normal
body: <p>I generated random 20 numbers with mean 0 and variance 1 (np.random.normal). I calculated the variance twice ddof = 1 and 0.</p>
  
  <p>My question is i am trying to add (mean 0 and variance 1) to (np.random.normal), However on there website is no mention for the variance  <a href="https://docs.scipy.org/doc/numpy/reference/generated/numpy.random.normal.html" rel="noreferrer">https://docs.scipy.org/doc/numpy/reference/generated/numpy.random.normal.html</a></p>
  
  <pre><code>loc : float Mean (“centre”) of the distribution.
  scale : float Standard deviation (spread or “width”) of the distribution.
  size : int or tuple of ints, optional
  </code></pre>
  
  <p>So can i just do it like this </p>
  
  <pre><code> mu, sigma = 0, math.sqrt(1) 
   x = np.random.normal(mu, sigma, 20)
  </code></pre>
  
  <p>Because i have to perform the estimation in 90 times and 20 numbers each time  and recount again </p>
  
  <pre><code>a = np.random.rand(90, x)
  </code></pre>
  
  <p>Here is the full code</p>
  
  <pre><code>import math
  import numpy as np
  import pandas as pd
  mu, sigma = 0, math.sqrt(1) 
  x = np.random.normal(mu, sigma, 20)
  
  
  #caluclateing the unbiased_estimator and the biased_estimator
  unbiased_estimator = np.var(x, ddof=1)
  biased_estimator = np.var(x, ddof=0)
  
  
  print ("Unbiased_estimator : ",unbiased_estimator)
  print ("Biased_estimator   : ", biased_estimator)
  
  a = np.random.rand(90, x)
  #caluclateing the unbiased_estimator and the biased_estimator
  unbiased_estimator_for_each_20 = np.var(a, ddof=1, axis=1)
  biased_estimator_for_each_20 = np.var(a, ddof=0, axis=1)
  
  print (unbiased_estimator_for_each_20 )
  print(" ")
  print (biased_estimator_for_each_20 )
  </code></pre>