| Re: IDL FOR Loop variable increments [message #62578 is a reply to message #62575] |
Sun, 21 September 2008 15:37   |
raghuram
Messages: 32
Registered: February 2008
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Member |
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On Sep 21, 6:44 am, Bulrush <Wasit.Weat...@gmail.com> wrote:
> On Sep 20, 12:51 am, Raghu <raghuram.narasim...@gmail.com> wrote:
>
>
>
>> On Sep 19, 12:09 pm, pgri...@gmail.com wrote:
>
>>> R.G. Stockwell wrote:
>>>> "Jean H" <jghas...@DELTHIS.ucalgary.ANDTHIS.ca> wrote in message
>>>> news:gauiil$u32$1@news.ucalgary.ca...
>>>> ...
>>>> > Could you comment on the "risk" of changing the loop counter within the
>>>> > loop?
>
>>>> my 2 cents.
>
>>>> First, it is in changing the counter of a for loop.
>>>> A for loop explicitly outlines what all counter variables will be.
>
>>>> There are two things:
>
>>>> 1) infinite loop, one could easily change the counter to never
>>>> reach the end condition. A (valid) for loop will always reach the end
>>>> condition.
>
>>>> 2) more insidious, you could inadvertantly cast the counter to a float from
>>>> an int, and then have one extra (and unintended ) statement executed.
>
>>> This seems not to be possible in IDL, as loop counters, unlike normal
>>> variables, cannot change their type.
>
>>> Ciao,
>>> Paolo
>
>>>> instead of 0,1,2,3,4,5,6 (and not executing i = 7) you could get
>>>> 0,1,2,3,4,4.99999999,5.99999,6.99999999, (and effectively executing the
>>>> extra i ~ 7 step).
>
>>>> Cheers,
>>>> bob
>
>> Hi all,
>
>> Thanks for your replies. Just as David mentioned in his first
>> response, a while loop worked out much better. Within a single while
>> loop, i was able to accomplish the task, albeit a bit slowly because
>> of the non-array operation.
>
>> Thanks !- Hide quoted text -
>
>> - Show quoted text -
>
> Why not you do not share your final results with us to close this
> post.
> Elkunn
Hi,
I will. I don't have the code with me this weekend. I'll post it on
Monday at work.
Thanks,
Raghu
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