## question about the using of the loop function

on 7 Jun 2014
Latest activity Commented on by Star Strider

on 7 Jun 2014

### Star Strider (view profile)

Hello, How can I use the final results obtained from the first iteration of a loop function in the second iteration of the same loop? For example, let T=[100:200], and A(T0) and k are constant known values. for T=T1, I want to calculate the following: I(T1)=A(T0).* exp(T1)

A(T1)=I(T1).* k

However, for T=T2, I want to calculate:

I(T2)= A(T1).* exp(T2)

A(T2)=I(T2).*k

and,

fot T=T3,

I(T3)= A(T2).* exp(T3)....and so on.

A(T3)=I(T3) Thanks

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### Star Strider (view profile)

on 7 Jun 2014

With T that large, you quickly end up with an array of Inf values.

This loop will do what you want:

```A0 = 3;
k = 5;
I(1) = A0 * exp(100);
A(1) = I(1)*k;
for T = 2:100
I(T)= A(T-1).* exp(T+99);
A(T) = I(T)*k;
end
```

I started the loop counter at 1 rather than 100 because otherwise your arrays are padded with 99 zeros. That takes up memory.

on 7 Jun 2014

Thank you. This is exactly what I want. I will try to apply it now on my real equations.

Star Strider

### Star Strider (view profile)

on 7 Jun 2014

My pleasure!

(The sincerest form of appreciation here on MATLAB Answers is to Accept the Answer that most closely solves your problem.)

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