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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. | ||
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 | ||
>>> from tempfile import TemporaryFile | ||
>>> outfile = TemporaryFile() | ||
>>> p = 100 # 100 elements are to be sorted | ||
>>> mu, sigma = 0, 1 # mean and standard deviation | ||
>>> X = np.random.normal(mu, sigma, p) | ||
>>> np.save(outfile, X) | ||
>>> print('The array is') | ||
>>> 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 | ||
>>> mu, sigma = 0, 1 # mean and standard deviation | ||
>>> s = np.random.normal(mu, sigma, p) | ||
>>> count, bins, ignored = plt.hist(s, 30, normed=True) | ||
>>> plt.plot(bins , 1/(sigma * np.sqrt(2 * np.pi)) *np.exp( - (bins - mu)**2 / (2 * sigma**2) ),linewidth=2, color='r') | ||
>>> plt.show() | ||
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``` | ||
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----- | ||
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![](https://www.mathsisfun.com/data/images/normal-distrubution-large.gif) | ||
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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 | ||
>>>import matplotlib.pyplot as plt | ||
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# Normal Disrtibution QuickSort is red | ||
>>> 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 | ||
>>> 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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------------------ | ||
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