why all of my variables become NaN or inf after I run my function

Hi

I have this function when I run it it gives me the results, but all the variables become zero at the end. I mean when Matlab run it, it gives me the final value for f but I cannot find the value of t1 t2 Inspcost ...., my code is as follow:

function f=optim(x)
%%%%%x1 H2 for com 1, x2 for interval
H1=1.25;
CI=580;
Cp=3000;       
Cr=2000;
t1=ones(1,5);
t2=ones(1,5);
for j=2:5 % number of intervals 
    t1(j)=j*x(2);
    t2(j)=(j-1)*x(2);
     Inspcost1(j)=MyF(x(1),t1(j));
     Inspcost2(j)=MyF(x(1),t2(j));
     Inspcostall(j)=(j-1).*abs((Inspcost2(j)-Inspcost1(j)));
end
Inspcost=CI*sum(Inspcostall(j));  %%%%%first item in numerator
for j=2:5   % this is for Intervals
  Downcost1(j)=abs(Inspcost2(j)-Inspcost1(j));  %%%%first part in downtime cost
  Down211(j)=MyF(H1,t1(j));    
  Down212(j)=MyF(H1,t2(j));
  Down21(j)= t1(j).*abs(Down212(j)-Down211(j));    %%%%(1) in second part in downtime cost
  Down22(j)=abs(t1(j).*(1-Down211(j))-t2(j).*(1-Down212(j)));  %%%%(2) in second part in downtime cost

    for m=1:2
        Down23each(j,m)=IntF(H1,m,t2(j),t1(j));    %%%%(3) in second part in downtime cost
    end
  end
  for j=2:5 
    Down23(j)=sum(Down23each(j,:));    %%%%(3) in second part in downtime cost
    Downcost2(j)=Down21(j)-Down22(j)+Down23(j);  %%%%total second part in downtime cost
    Downall1(j)=Downcost1(j).*Downcost2(j);
  end

Downcost=Cp*sum(Downall1);    %%%%%second item in numerator
for j=2:5
    t1
    Lencycle1(j)=t1(j).*abs((Inspcost2(j)-Inspcost1(j)));  
end
Lenthcycle=sum(Lencycle1);  %%%%%denominator 
Totalcost=Inspcost+Downcost+Cr;  %%%%total  numerator
t1
t2
f=10*Totalcost/Lenthcycle;
|

• for example for x=[1.1,1] I can find the value of f, but I get this error when I want to find the exact value of my variables, they are undefined or zero:|

>> t2
Undefined function or variable 't2'.
 >> Inspcost
Undefined function or variable 'Inspcost'.

t1 =

       0     0     0     0     0     0     0     0     0     0

Answer 1

[Walter Roberson]

Every function has its own "workspace". Variables defined in a function that are not specifically constructed as being permanent or somehow shared, are destroyed when the function returns.

In order to examine those values you need to do one of the following:

• Return the variables from the function; or
• put a breakpoint in the function and examine the variable before return; or
• share the variable using one of the techniques described at http://matlab.wikia.com/wiki/FAQ#How_can_I_share_data_between_callback_functions_in_my_GUI.28s.29.3F