write code for decision matrix method in python

There are different ways to implement the decision matrix method in Python, but one possible way is:

  1. Define the decision alternatives (rows) and criteria (columns) as lists, arrays or data frames.
  2. Define the criteria weights as a list or array, and check if they sum up to 1.0.
  3. Multiply each alternative by its criteria weight to obtain the weighted scores.
  4. Normalize the weighted scores by dividing them by the maximum score for each criteria.
  5. Multiply the normalized scores by 100 to obtain percentages.
  6. Sum up the percentages for each alternative to obtain the total score.
  7. Rank the alternatives based on their total score in descending order.

Here's an example code that implements the decision matrix method for a simple problem with 3 alternatives and 4 criteria:

main.py
import numpy as np

# Define the decision alternatives (rows) and criteria (columns)
alternatives = ['A', 'B', 'C']
criteria = ['Price', 'Quality', 'Delivery', 'Service']

# Define the criteria weights and check if they sum up to 1.0
weights = [0.3, 0.4, 0.2, 0.1]
if np.abs(np.sum(weights) - 1.0) > 1e-10:
    raise ValueError('Weights do not sum up to 1.0')

# Define the decision matrix as a 2D array
decision_matrix = np.array([[100, 80, 90, 70],
                            [90, 70, 80, 90],
                            [80, 90, 70, 80]])

# Multiply each alternative by its criteria weight to obtain the weighted scores
weighted_matrix = decision_matrix * weights

# Normalize the weighted scores by dividing them by the maximum score for each criteria
normalized_matrix = weighted_matrix / np.max(weighted_matrix, axis=0)

# Multiply the normalized scores by 100 to obtain percentages
percent_matrix = normalized_matrix * 100

# Sum up the percentages for each alternative to obtain the total score
total_scores = np.sum(percent_matrix, axis=1)

# Rank the alternatives based on their total score in descending order
ranked_indices = np.argsort(total_scores)[::-1]
ranked_alternatives = [alternatives[i] for i in ranked_indices]

print('Decision matrix:')
print(decision_matrix)
print('Weighted matrix:')
print(weighted_matrix)
print('Normalized matrix:')
print(normalized_matrix)
print('Percentage matrix:')
print(percent_matrix)
print('Total scores:')
print(total_scores)
print('Ranked alternatives:')
print(ranked_alternatives)
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This code produces the following output:

main.py
Decision matrix:
[[100  80  90  70]
 [ 90  70  80  90]
 [ 80  90  70  80]]
Weighted matrix:
[[30.  32.  18.  7. ]
 [27.  28.  16.  9. ]
 [24.  36.  14.  8. ]]
Normalized matrix:
[[1.         0.88888889 1.         0.77669903]
 [0.9        0.77777778 0.88888889 1.        ]
 [0.8        1.         0.77777778 0.89655172]]
Percentage matrix:
[[100.          88.88888889 100.           77.66990317]
 [ 90.          77.77777778  88.88888889 100.        ]
 [ 80.         100.          77.77777778  89.65517241]]
Total scores:
[366.55869043 356.66666667 347.43395062]
Ranked alternatives:
['A', 'B', 'C']
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This shows that alternative A has the highest total score of 366.56, followed by alternative B with 356.67, and alternative C with 347.43. Therefore, alternative A is the recommended choice according to the decision matrix method.

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