Upload New File

tp9/merge_sort_analysis.py

+#!/usr/bin/python3
+# -*- coding: utf-8 -*-
+
+"""
+:mod:`mergesort_analysis` module
+:author: FIL - FST - Univ. Lille <http://portail.fil.univ-lille.fr>_
+:date: 2024, April. 
+
+Experimental analysis of mergesort algorithm
+
+"""
+from aplst import ApLst
+from merge_sort import compare, mergesort, native_to_list
+from ap_decorators import count
+
+
+import random
+import matplotlib.pyplot as plt
+from math import log
+
+def random_list(size: int) -> ApLst:
+    '''
+    :param size: (int)
+    :return: (list) list of size size containing all natural numbers from 0 to n-1 in random order
+    :CU: n >= 0
+    '''
+    l = list(range(size))
+    random.shuffle(l)
+    return native_to_list(l)
+
+
+def myplot(listX: list[float], listY: list[float],
+           title: str='', xlabel: str ='', ylabel: str=''):
+    '''
+    plot the data in listX and listY
+    '''
+    plt.plot(listX, listY)
+    plt.title(title)
+    plt.xlabel(xlabel)
+    plt.ylabel(ylabel)
+    plt.show()
+
+
+def build_comp_number_list(sort, max_size: int, sample_size: int) -> list[float]:
+    '''
+    return: list of average number of comparisons for sorting lists of size up to max_size
+    '''
+    comp = count(compare)
+    nb_comps = []
+    for size in range(1, max_size):
+        comp.counter = 0
+        for _ in range(sample_size):
+            sort(random_list(size), comp=comp)
+        nb_comps.append(comp.counter / sample_size)
+    return nb_comps
+
+
+def usage():
+    print('Usage: {:s} <max size> <sample size>'.format(sys.argv[0]),
+          file=sys.stderr)
+    print('\t<max size> = max size of lists to sort', file=sys.stderr)
+    print('\t<sample size> = size of samples.', file=sys.stderr)
+    exit(1)
+    
+if __name__ == '__main__':
+    import sys
+    
+    if len(sys.argv) != 3:
+        print('Bad number of arguments!', file=sys.stderr)
+        usage()
+
+    try:
+        MAX_SIZE = int(sys.argv[1])
+    except ValueError:
+        print('Max size must be an integer!', file=sys.stderr)
+        usage()
+
+    SIZES = list(range(1, MAX_SIZE))
+    
+    try:
+        SAMPLE_SIZE = int(sys.argv[2])
+    except ValueError:
+        print('Sample size must be an integer!', file=sys.stderr)
+        usage()
+
+    # all is OK!
+    NB_COMPS = build_comp_number_list(mergesort, MAX_SIZE, SAMPLE_SIZE)
+    myplot(SIZES, NB_COMPS,
+           title=f'Nbre de comparaisons du tri fusion (mesuré sur échantillon de taille {SAMPLE_SIZE})',
+           xlabel='taille des listes',
+           ylabel='nbre de comparaisons')
+