program error :Unbalanced or unexpected parenthesis or bracket

Hi all

I wrote a program for below formula , but when i run it , it face an error (Unbalanced or unexpected parenthesis or bracket.)

and also for C calculated amount I need a fixation : when calculated C from above formula is less than 0 put C=0 and when C is amount from above formula is bigger than 0 put C=calculated amount ( i mean for exmple when it become -20 then put C=0 and for example when C=20 put C=20 and make no changes)

I attached the program but for certain I write the code here :

clc;
clear;
r=0.01;
u=0.05;
d=-0.04;
n=4;
j=0;
St=40;
K=25;
p=(r-d)/(u-d)
C=(1/(1+r)^n)*(symsum(nchoosek(n,j)*p^j*(1-p)^(n-j)*max(0,((1+u)^j)*(1+d)^(n-j)*St/K))),j,0,n)

Could anyone help me and fix change the program to work and fix C amount

I'm in hurry and just have 2 hours

plz help me

thank you all

[amir khalighi]

I've changed it to code below but gives me different C and doesn't sum them

clc;
clear;
r=0.01;
u=0.05;
d=-0.04;
n=4;
St=30;
K=25;
p=(r-d)/(u-d);
pi=1-p;
for i=0:n;
    v=nchoosek(n,i);
    X=((1+u)^i*(1+d)^(n-i)*St-K);
    t=max(0,X);
    C=1/((1+r)^n)*v*(p^i)*(p^(n-i)*t)
end

and also for C calculated amount I need a fixation : when calculated C from above formula is less than 0 put C=0 and when C is amount from above formula is bigger than 0 put C=calculated amount ( i mean for exmple when it become -20 then put C=0 and for example when C=20 put C=20 and make no changes)|

[Ameer Hamza]

You are not adding previous values. Change your code like below. C is incremented in each loop.

clc;
clear;
r=0.01;
u=0.05;
d=-0.04;
n=4;
St=30;
K=25;
p=(r-d)/(u-d);
pi=1-p;
C = 0;
for i=0:n;
  v=nchoosek(n,i);
  X=((1+u)^i*(1+d)^(n-i)*St-K);
  t=max(0,X);
  C=C+1/((1+r)^n)*v*(p^i)*(p^(n-i)*t)
end

[amir khalighi]

Yes that's right

it works well not and for c<0 what should i do?i want them to change to 0 and them sum with other c

[Ameer Hamza]

What do you mean? If C < 0, you want to make C = 0?

[amir khalighi]

when calculated C from above formula is less than 0 put C=0 and when C is amount from above formula is bigger than 0 put C=calculated amount ( i mean for exmple output c is -20 -10 and 10 then put final C=0+0+10=10 and for example when C=20 put C=20 and make no changes) I don't know it was clear or not

[Ameer Hamza]

It appears that what you are saying can be done as follow, replace this line in your code.

C = C + max(1/((1+r)^n)*v*(p^i)*(p^(n-i)*t), 0);

replace this line in your code.

[amir khalighi]

awsome

thank you very very much :)

[Ameer Hamza]

You are welcome.

Answer 1

[Ameer Hamza]

As evident from the error message, you are having unbalanced brackets. You should clearly pay attention to error messages. Also max() function will only work on symbolic expression if you clearly describe its type. Here is the corrected code

clc;
clear;
r=0.01;
u=0.05;
d=-0.04;
n=4;
syms k integer;
St=40;
K=25;
p=(r-d)/(u-d);
C=(1/(1+r)^n)*symsum((nchoosek(n,k).*p.^k*(1-p).^(n-k).*max(0,((1+u).^k).*(1+d).^(n-k).*St/K)),k,0,n);

[amir khalighi]

Error using sym/max (line 97) Input arguments must be convertible to floating-point numbers.

Error in math (line 11) C=(1/(1+r)^n)*symsum((nchoosek(n,k).*p.^k*(1-p).^(n-k).*max(0,((1+u).^k).*(1+d).^(n-k).*St/K)),k,0,n);

• what should i do now?

[Ameer Hamza]

Have you ran the following line.

syms k integer;

I also changed variable name from j to k, to avoid conflict with MATLAB internal constant.