Using Bisection Search in the lowest credit card debt payments and

Question

My code is:

monthlyInterestRate = annualInterestRate/12.0 low = balance/12 high = (balance*(1+monthlyInterestRate)**12)/12 guess = (low+high)/2 unpaidBalance = balance month = 1 while True: unpaidBalance= unpaidBalance-guess while month < 13: if unpaidBalance <= -0.1: low = guess month += 1 elif unpaidBalance >= 0.1: high = guess month += 1 else: break guess = (low + high)/2 print "Lowest Payment: " + str(round(guess, 2)) 

When I test it, it gets stuck in the line "while month <13:"

Why is he doing this and how to fix it?

Answer 1

If you break every cycle of the inner while, you stay less than 13.

And it goes on and on as you continue While True and not update your guess .

I am afraid that you are faced with an endless cycle.

Your break statement breaks the closest loop, i.e. the While month < 13 loop. The next line is not readable. guess not updated. While True not broken.

Perhaps you wanted to say

 while month < 13: unpaidBalance= unpaidBalance-guess if unpaidBalance <= -0.1: low = guess elif unpaidBalance >= 0.1: high = guess month += 1 guess = (low + high)/2 

Answer 2

Here you

No, this is the best solution, but it works.

 monthlyPaymentRate = (balance*annualInterestRate/12)/((1-(1+annualInterestRate/12)**-12)) interest = monthlyPaymentRate * (annualInterestRate/12) #print (monthlyPaymentRate) #print (interest) monthlyPaymentRate = (monthlyPaymentRate - interest) +1 #print (monthlyPaymentRate) balanceInit = balance epsilon = 0.01 low = monthlyPaymentRate while low*12 - balance > epsilon: balances = balanceInit for i in range(12): minpay = monthlyPaymentRate unpaybal = balances - minpay interest = (annualInterestRate /12) * unpaybal smontfinal = unpaybal + interest balances = smontfinal #print('Remaining balance: ' ,round(balances,2) ) if balances <0: low = -1 break if balances < 0 : low = -1 else: monthlyPaymentRate =monthlyPaymentRate + 0.001 print('Lowest Payment:' ,round(monthlyPaymentRate,2) )