optim_lab6.py

##----python 3.5* version----
##Author name: Mariam Anayan-
##------Variant: 1-----------
import sys
import math

out = sys.stdout

float_format  = '{:8.2f}'
answer_format = 'Optimal strategy is {:d}, value for it {:.2f}'
separator = '\n' + '-'* 30 + '\n'

probability = 0.5

def max_in_column(matrix, column_index):
    max_value = - math.inf
    for i in range(len(matrix)):
        max_value = max(max_value, matrix[i][column_index])

    return max_value

def Bernoulli_model(matrix):
    print('--Bernoulli model--', file = out)
    max_value = - math.inf
    max_value_raw = -1

    for i in range(len(matrix)):
        #just to avoid float division
        if sum(matrix[i]) > max_value:
            max_value_raw = i
            max_value = sum(matrix[i])

    print_answer(max_value_raw, max_value/len(matrix[max_value_raw]))
    return max_value_raw, max_value/len(matrix[max_value_raw])

def Wald_model(matrix):
    print('--Wald model--', file = out)
    max_value = - math.inf
    max_value_raw = -1

    for i in range(len(matrix)):
        if min(matrix[i]) > max_value:
            max_value_raw = i
            max_value = min(matrix[i])

    print_answer(max_value_raw, max_value)
    return max_value_raw, max_value

def max_model(matrix):
    print('--Max model--', file = out)
    max_value = - math.inf
    max_value_raw = -1

    for i in range(len(matrix)):
        if max(matrix[i]) > max_value:
            max_value_raw = i
            max_value = max(matrix[i])

    print_answer(max_value_raw, max_value)
    return max_value_raw, max_value

def Hurwitz_model(matrix, probability):
    print('--Hurwitz model--', file = out)
    max_value = - math.inf
    max_value_raw = -1

    for i in range(len(matrix)):
        temp_value = probability * min(matrix[i]) + (1 - probability)* max(matrix[i])
        if temp_value > max_value:
            max_value_raw = i
            max_value = temp_value

    print_answer(max_value_raw, max_value)
    return max_value_raw, max_value

def Savage_model(matrix):
    print('--Savage model--', file = out)
    min_value = math.inf
    min_value_raw = -1

    risk_matrix = []
    for i in range(len(matrix)):
        risk_matrix.append([0] * len(matrix[i]))


    for i in range(len(matrix)):
        temp_max_value = -math.inf

        for j in range(len(matrix[i])):
            risk_matrix[i][j] = max_in_column(matrix, j) - matrix[i][j]
            temp_max_value = max(risk_matrix[i][j], temp_max_value)


        if temp_max_value < min_value:
            min_value = temp_max_value
            min_value_raw = i

    print('----Risk matrix is----', file = out)
    print_matrix(risk_matrix, "")

    print_answer(min_value_raw, min_value)
    return min_value_raw, min_value

def input_matrix(matrix_file):
    buffer = []
    matrix = []

    while True:
        buffer = matrix_file.readline()
        if not buffer:
            break
        buffer = list(map(float, buffer.split()))
        matrix.append(buffer)
    return matrix

def print_matrix(matrix, message):
    print(message, file = out)
    for raw in matrix:
        for element in raw:
            print(float_format.format(element), end = " ", file = out)
        print(file = out)
    print(file = out)

def print_answer(index, value):
     print(answer_format.format(index, value), separator, file = out)

def main():
    global out

    matrix_file = open('{:}.txt'.format(input('Please, enter filename (.txt):')), 'r')
    if input('Do you want write to the file (y/n)? ') == 'y':
        out = open('{:}.txt'.format(input('Please, enter filename (.txt):')), 'w')

    matrix = input_matrix(matrix_file)
    print_matrix(matrix, '-- Your matrix is --')

    Bernoulli_model(matrix)
    Wald_model(matrix)
    max_model(matrix)
    Hurwitz_model(matrix, probability)
    Savage_model(matrix)
    out.close()

if __name__ == '__main__':
    main( )