Evaluating association strengths of items












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$begingroup$


Say I have a list of animals with their counts:



import numpy as np
import pandas as pd
from random import randint

table = np.zeros((5,1), dtype=int)
for i in range(5):
table[i]=randint(10, 20)

df1 = pd.DataFrame(columns=['Animal', 'Count'])
df1['Animal'] = animal_list
df1['Count'] = table
df1


enter image description here



And I have a matrix of how many times they appear together:



table = np.zeros((5,5), dtype=int)
animal_list = ['Monkey', 'Tiger', 'Cat', 'Dog', 'Lion']

for i in range(5):
for j in range(5):
table[i][j]=randint(0, 9)

df2 = pd.DataFrame(table, columns=animal_list, index=animal_list)
df2


enter image description here



I want to find the animals' association strength, which is defined like so - if Lion and Cat appear together 5 times, and Lion's count is 10 and Cat's count is 15, then Lion -> Cat association strength is 5/10=0.5, and Cat -> Lion association strength is 5/15=0.33.



I do it like so:



assoc_df = pd.DataFrame(columns=['Animal 1', 'Animal 2', 'Association Strength'])
for row_word in df2:
for col_word in df2:
if row_word!=col_word:
assoc_df = assoc_df.append({'Animal 1': row_word, 'Animal 2': col_word,
'Association Strength': df2[col_word][row_word]/df1[df1.Animal==row_word]['Count'].values[0]}, ignore_index=True)

assoc_df


enter image description here



The problem is, since there are 2 for loops, the complexity is O(n^2). This is a problem when (in my real dataset) I have ~1000 animals to loop on, which takes hours to finish computing the association strength table.



So, how to do I better optimize the creation/generation process of this association table?









share









$endgroup$

















    0












    $begingroup$


    Say I have a list of animals with their counts:



    import numpy as np
    import pandas as pd
    from random import randint

    table = np.zeros((5,1), dtype=int)
    for i in range(5):
    table[i]=randint(10, 20)

    df1 = pd.DataFrame(columns=['Animal', 'Count'])
    df1['Animal'] = animal_list
    df1['Count'] = table
    df1


    enter image description here



    And I have a matrix of how many times they appear together:



    table = np.zeros((5,5), dtype=int)
    animal_list = ['Monkey', 'Tiger', 'Cat', 'Dog', 'Lion']

    for i in range(5):
    for j in range(5):
    table[i][j]=randint(0, 9)

    df2 = pd.DataFrame(table, columns=animal_list, index=animal_list)
    df2


    enter image description here



    I want to find the animals' association strength, which is defined like so - if Lion and Cat appear together 5 times, and Lion's count is 10 and Cat's count is 15, then Lion -> Cat association strength is 5/10=0.5, and Cat -> Lion association strength is 5/15=0.33.



    I do it like so:



    assoc_df = pd.DataFrame(columns=['Animal 1', 'Animal 2', 'Association Strength'])
    for row_word in df2:
    for col_word in df2:
    if row_word!=col_word:
    assoc_df = assoc_df.append({'Animal 1': row_word, 'Animal 2': col_word,
    'Association Strength': df2[col_word][row_word]/df1[df1.Animal==row_word]['Count'].values[0]}, ignore_index=True)

    assoc_df


    enter image description here



    The problem is, since there are 2 for loops, the complexity is O(n^2). This is a problem when (in my real dataset) I have ~1000 animals to loop on, which takes hours to finish computing the association strength table.



    So, how to do I better optimize the creation/generation process of this association table?









    share









    $endgroup$















      0












      0








      0





      $begingroup$


      Say I have a list of animals with their counts:



      import numpy as np
      import pandas as pd
      from random import randint

      table = np.zeros((5,1), dtype=int)
      for i in range(5):
      table[i]=randint(10, 20)

      df1 = pd.DataFrame(columns=['Animal', 'Count'])
      df1['Animal'] = animal_list
      df1['Count'] = table
      df1


      enter image description here



      And I have a matrix of how many times they appear together:



      table = np.zeros((5,5), dtype=int)
      animal_list = ['Monkey', 'Tiger', 'Cat', 'Dog', 'Lion']

      for i in range(5):
      for j in range(5):
      table[i][j]=randint(0, 9)

      df2 = pd.DataFrame(table, columns=animal_list, index=animal_list)
      df2


      enter image description here



      I want to find the animals' association strength, which is defined like so - if Lion and Cat appear together 5 times, and Lion's count is 10 and Cat's count is 15, then Lion -> Cat association strength is 5/10=0.5, and Cat -> Lion association strength is 5/15=0.33.



      I do it like so:



      assoc_df = pd.DataFrame(columns=['Animal 1', 'Animal 2', 'Association Strength'])
      for row_word in df2:
      for col_word in df2:
      if row_word!=col_word:
      assoc_df = assoc_df.append({'Animal 1': row_word, 'Animal 2': col_word,
      'Association Strength': df2[col_word][row_word]/df1[df1.Animal==row_word]['Count'].values[0]}, ignore_index=True)

      assoc_df


      enter image description here



      The problem is, since there are 2 for loops, the complexity is O(n^2). This is a problem when (in my real dataset) I have ~1000 animals to loop on, which takes hours to finish computing the association strength table.



      So, how to do I better optimize the creation/generation process of this association table?









      share









      $endgroup$




      Say I have a list of animals with their counts:



      import numpy as np
      import pandas as pd
      from random import randint

      table = np.zeros((5,1), dtype=int)
      for i in range(5):
      table[i]=randint(10, 20)

      df1 = pd.DataFrame(columns=['Animal', 'Count'])
      df1['Animal'] = animal_list
      df1['Count'] = table
      df1


      enter image description here



      And I have a matrix of how many times they appear together:



      table = np.zeros((5,5), dtype=int)
      animal_list = ['Monkey', 'Tiger', 'Cat', 'Dog', 'Lion']

      for i in range(5):
      for j in range(5):
      table[i][j]=randint(0, 9)

      df2 = pd.DataFrame(table, columns=animal_list, index=animal_list)
      df2


      enter image description here



      I want to find the animals' association strength, which is defined like so - if Lion and Cat appear together 5 times, and Lion's count is 10 and Cat's count is 15, then Lion -> Cat association strength is 5/10=0.5, and Cat -> Lion association strength is 5/15=0.33.



      I do it like so:



      assoc_df = pd.DataFrame(columns=['Animal 1', 'Animal 2', 'Association Strength'])
      for row_word in df2:
      for col_word in df2:
      if row_word!=col_word:
      assoc_df = assoc_df.append({'Animal 1': row_word, 'Animal 2': col_word,
      'Association Strength': df2[col_word][row_word]/df1[df1.Animal==row_word]['Count'].values[0]}, ignore_index=True)

      assoc_df


      enter image description here



      The problem is, since there are 2 for loops, the complexity is O(n^2). This is a problem when (in my real dataset) I have ~1000 animals to loop on, which takes hours to finish computing the association strength table.



      So, how to do I better optimize the creation/generation process of this association table?







      python performance python-3.x community-challenge data-mining





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      asked 5 mins ago









      Kristada673Kristada673

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