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Merge pull request #66 from prateekiiest/master
Update Normal Distribution QuickSort Readme
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###### View the algorithm in [action][quick-toptal]
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###### View the algorithm in [action][quick-toptal]
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![Normal Distribution QuickSort](https://github.com/prateekiiest/Python/blob/master/sorts/normal_distribution_QuickSort_README.md)
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### Selection
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### Selection
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![alt text][selection-image]
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![alt text][selection-image]
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sorts/normal_distribution_QuickSort_README.md
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sorts/normal_distribution_QuickSort_README.md
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#Normal Distribution QuickSort
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Algorithm implementing QuickSort Algorithm where the pivot element is chosen randomly between first and last elements of the array and the array elements are taken from a Standard Normal Distribution.
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This is different from the ordinary quicksort in the sense, that it applies more to real life problems , where elements usually follow a normal distribution. Also the pivot is randomized to make it a more generic one.
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##Array Elements
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The array elements are taken from a Standard Normal Distribution , having mean = 0 and standard deviation 1.
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####The code
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```python
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>>> import numpy as np
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>>> from tempfile import TemporaryFile
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>>> outfile = TemporaryFile()
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>>> p = 100 # 100 elements are to be sorted
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>>> mu, sigma = 0, 1 # mean and standard deviation
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>>> X = np.random.normal(mu, sigma, p)
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>>> np.save(outfile, X)
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>>> print('The array is')
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>>> print(X)
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```
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------
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#### The Distribution of the Array elements.
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```python
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>>> mu, sigma = 0, 1 # mean and standard deviation
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>>> s = np.random.normal(mu, sigma, p)
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>>> count, bins, ignored = plt.hist(s, 30, normed=True)
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>>> plt.plot(bins , 1/(sigma * np.sqrt(2 * np.pi)) *np.exp( - (bins - mu)**2 / (2 * sigma**2) ),linewidth=2, color='r')
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>>> plt.show()
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```
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![Array_Element_Distribution](https://github.com/prateekiiest/Algorithms/blob/master/normaldistributionforarrayelements.png)
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---
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---------------------
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--
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##Plotting the function for Checking 'The Number of Comparisons' taking place between Normal Distribution QuickSort and Ordinary QuickSort
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```python
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>>>import matplotlib.pyplot as plt
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# Normal Disrtibution QuickSort is red
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>>> plt.plot([1,2,4,16,32,64,128,256,512,1024,2048],[1,1,6,15,43,136,340,800,2156,6821,16325],linewidth=2, color='r')
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#Ordinary QuickSort is green
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>>> plt.plot([1,2,4,16,32,64,128,256,512,1024,2048],[1,1,4,16,67,122,362,949,2131,5086,12866],linewidth=2, color='g')
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>>> plt.show()
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```
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----
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###The Plot
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* X axis denotes the number of elements to be sorted.
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* Y axis denotes the number of comparisons taking place
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![Plot](https://github.com/prateekiiest/Algorithms/blob/master/normaldist.png)
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------------------
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