Question

Why is error ? 'int object not callable'

high = (balance(1 + monthlyInterestRate)**12)/12

http://codepad.org/L6SUqoTC

Unfortunately, I have limited idea how this one works it hasn't sunk in yet, maybe I need a breakl

Answer 1

u forgot an operator there so maybe thats why?

Answer 2

Spend time to fully understand the math in this problem and the bisection method.
And stop programming so late at night xD! makes u make mistakes:P

Plus, i dont know if im wrong but, wouldn't it be better to assure this will be a float division by dividing it with 12.0 and not 12 ,that could give you an integer division and create wrong results?

Answer 3

Yes Ill do that in morning, Thanks (Haven't really got a grip of the bisection method yet)

Answer 4

It's very tricky the bisection method, try with a simple example, and gradually make it bigger.
Also @MicroBot the monthlyInterestRate (= annualInterestRate/12); is float because the annual rate is always a float number (0.2 or 0.4 or 0.18).

Answer 5

while (pay - balance)>= epsilon:
This line is wrong. pay is the *monthly* payment according to your code, and since the way you have coded this balance will never change, pay>>balance always so this loop will never terminate. You need to find a way to keep track of the balance (that should be updated every lop btw) that will result from a particular monthly payment.
I will tell you that I had to introduce a new variable about the balance to solve this problem, though I'm sure there are more ways.

Answer 6

also your pay=(high+low)/2 at the end seems to be on the wrong indent

Answer 7

I have no idea what int it thinks you are trying to call, but perhaps it is what @MicroBot says about the
high = (balance(1 + monthlyInterestRate)**12)/12
perhaps it thinks you are trying to call a function balance on (1 + monthlyInterestRate)**12 ??
that's just a guess though

Answer 8

so yeah, definitely put that operator in there

Answer 9

Yeah he miss the *
Another tip, epsilon is a tiny value (0.001 for example), as @TuringTest said is an endless loop, try to compare to a difference of values, maybe you can try to compare both balances, the current and the one you get with the pay obtained from your algorithm.

Answer 10

@turingtest
1: Yes, about the int problem i was thinking exsactly that...that since there is no operator, it thinks of it as a function call or smthing.

2: About the float division: i was talking again about the same statement
high = (balance(1 + monthlyInterestRate)**12)/12

that i believe it should be better written as:

high = (balance(1 + monthlyInterestRate)**12)/12.0

but seeing it now...since there is monthlyInterestRate in there it will be a float anyway:P

(see @minimallinux when you answer questions late at night and you are tired ,you say things non accurate:P)

Answer 11

The error is due to this high = (balance(1 + ... as microbot said in the first post missing operator. It needs to be high = (balance*(1 + ... notice the addition of the * operator. We understand that * is implied when we look at it but the computer does not, sometimes hard to spot as it 'looks normal' to us.