these code is how to find (the new mortgage values of a house), but I'm having troubles changing it to find (how long it will take to pay off a house).

disp('I can tell you how much you''ll have to pay for your house.')
disp([' '])
pv=input('What was your original mortgage value? ');
rate=input('What is the yearly interest rate on your home? ');
pmt=input('What is your mounthly payments? ');
nper=input('How many monthly payments have you made so far? ');
 
 m = (rate/100)/12;   
 nper = 10*12;       
 current_balance = 1:nper; 

for loop = 1 : nper
    pv = pv*(1+m)-pmt; 
    current_balance(loop) = pv;
	fprintf('The current balance after %d periods (out of %d) is %.2f\n', ...
		loop, nper, current_balance(loop));
end

All of the variables and the equation are still used, but Im thinking that I just need to change the fprintf line, but this is suppose to be in a while loop. I'm not sure if that changes much of the code

[darova]

Can you explain more? I don't understand the question

[Todd Wyzkiewicz]

The goal is to find the the amount of payments that it takes to pay off a mortgate. this is what i have not buit the "fprintf" line isn't calculating the right number for the count.

clear all
clc


disp('I can tell how long you''ll have to pay for your house.')
disp([' '])
pv=input('What was your present mortgage amount? ');
rate=input('What is the yearly interest rate on your mortgage? ');
pmt=input('How much are your mounthly payments? ');
fv=input('What is your future disired mortgage value? Hopefully its 0. ');

m = (rate/100)/12;
current_balance = pv;
loop = 0;

while current_balance > fv
    % do some calculation to pay off one month's worth of the balance?
   
    pv = pv*(1+m)-pmt;
    loop = loop + 1;
    current_balance(loop) = pv;

fprintf(['The current balance after %d periods (out of %f) that should be around %.2f\n'], ...
		loop, pv, current_balance(loop));
    
    disp('')
end

[darova]

Can you attach values for input?

[Todd Wyzkiewicz]

I can tell how long you'll have to pay for your house.
 
What was your present mortgage amount? 
150000
What is the yearly interest rate on your mortgage? 
3
How much are your mounthly payments? 
1200
What is your future disired mortgage value? Hopefully its 0. 
0
The current balance after 151 periods (out of -1122.331132) that should be around -1122.33

[Todd Wyzkiewicz]

These are the numbers I've been testing it with, the issue is that the "(out of ____)" should say (out of 151) for this example. I just dont know what is affecting the %d in the fprintf display.

[Todd Wyzkiewicz]

it's also a string of answers but that part isnt my biggist concern

.....
    The current balance after 145 periods (out of 6031.775155) that should be around 6031.78
The current balance after 146 periods (out of 4846.854593) that should be around 4846.85
The current balance after 147 periods (out of 3658.971730) that should be around 3658.97
The current balance after 148 periods (out of 2468.119159) that should be around 2468.12
The current balance after 149 periods (out of 1274.289457) that should be around 1274.29
The current balance after 150 periods (out of 77.475180) that should be around 77.48
The current balance after 151 periods (out of -1122.331132) that should be around -1122.33

[darova]

Today is late. Im going sleep. I'll take a look tomorrow. Ok?

[Todd Wyzkiewicz]

I acctually have to trun it in tonight so just don't worry about it. thanks though.

[Walter Roberson]

I explained the problem at https://www.mathworks.com/matlabcentral/answers/516704-while-loop-statement-errors#comment_824858

Answer 1

[James Browne]

Hello, I think I have found a solution for you, or at least something close:

disp('I can tell you how much you''ll have to pay for your house.')
disp([' '])
pv=input('What was your original mortgage value? ');
rate=input('What is the yearly interest rate on your home? ');
pmt=input('What is your mounthly payments? ');
nper=input('How many monthly payments have you made so far? ');
 
 m = (rate/100)/12;   
 nper = 10*12;       
 current_balance = 1:nper;
 loop = 0;
while pv > 0
    pv = pv*(1+m)-pmt; 
    loop = loop + 1;
    current_balance(loop) = pv;	
end

fprintf('It will take %d periods to pay off the loan\n',loop);

Hope this helps =)

[Walter Roberson]

nper=input('How many monthly payments have you made so far? ');

However you do not use that information. Instead you have

 nper = 10*12;

After that you initialize current_balance as a vector of 120 integers, 1:nper .

The loop then replaces some of those integers with balances, but if the payments are done in less than 10 years then it leaves some untouched. If the payments take more than 12 years then it will extend current_balance.

[Todd Wyzkiewicz]

I did notice that. I just took that line out.

[Todd Wyzkiewicz]

Sick! Thanks brother!

[James Browne]

Oh yea, good catch!