why is while loop used here?

Jack (view profile)

on 11 Sep 2013
Accepted Answer by Walter Roberson

Walter Roberson (view profile)

hello, I'm trying to understand why are we using while in this situation? what is it originally asking for? I don't understand he we got the i to be 3 and a to be 46 in the final answer

```x = [1:4];
```
```y = x.^2;
```
```z = x'*y;
```
```a = 1;
```
```while a<15
```
```for i=1:3
```
```a = a*x(i) + y(i);
```
```if a<4
```
```a = a + 2;
```
```end
```
```end
```
```a = a + 1;
```
```end
```
```a = 46
```
```i= 3
```

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Walter Roberson (view profile)

Answer by Walter Roberson

Walter Roberson (view profile)

on 11 Sep 2013

"while" is being used because someone wanted to write obscure code, possibly for teaching purposes.

Jack

Jack (view profile)

on 11 Sep 2013

can you please comment on how we got the i and a?

Walter Roberson

Walter Roberson (view profile)

on 11 Sep 2013

It looks to me like it is intended to be an exercise. Follow the logic through step by step, working on paper if you must. (I followed the logic through in my head and confirmed that the code will produce those answers.)

You could also learn to use the debugger, and let it execute the program step by step and watch the variables change.

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