For Loop Index Problems

[James Sherman Jr.]

I think you really want

while i < length(a),
  stuff inside your for loop,
end

Since you're already incrementing the "i" variable, you don't need the for
loop to "push" you along.

On Thu, Jun 4, 2009 at 2:40 PM, josgau33 <skankinkid33 at gmail.com> wrote:

>
> Hello,
>
> I am having a simple problem with the for loop and its index. Basically,
> here is a simple program to illustrate the problem I am having.
>
> i=1;
> a=[1 2 3 8 8 8 3 2 1];
>
> for i=1:length(a)
> i
>  while a(1,i)==8
>  i=i+1;
>  i
>  end
> i
> i=i+1;
> i
> end
>
> This gives the output shown below:
> i =  1
> i =  1
> i =  2
> i =  2
> i =  2
> i =  3
> i =  3
> i =  3
> i =  4
> i =  4
> i =  5
> i =  6
> i =  7
> i =  7
> i =  8
> i =  5
> i =  6
> i =  7
> i =  7
> i =  8
> i =  6
> i =  7
> i =  7
> i =  8
> i =  7
> i =  7
> i =  8
> i =  8
> i =  8
> i =  9
> i =  9
> i =  9
> i =  10
>
> So from here, we can see that... When a=8, the while loop is entered, and i
> equals 7 when it leaves the while loop... We then see that i=7 right
> outside
> of the while loop, and that after i=i+1, i now equals 8. But then, the next
> iteration of the for loop sets i equal to 5, which was the next iteration
> originally (before the while loop was entered).
>
> My question is... Is there any way to avoid the resetting of the index? Is
> there some sort of for loop where the user is allowed to control the index,
> and not the computer. If not, can anybody show me modifications to the code
> that would solve this problem? I cannot seem to figure it out on my own.
> Suggestions would be helpful too. Thank you,
>
> Joseph Gauthier
> --
> View this message in context:
> http://www.nabble.com/For-Loop-Index-Problems-tp23875595p23875595.html
> Sent from the Octave - General mailing list archive at Nabble.com.
>
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