On Sep 21, 3:37 pm, Raghu <raghuram.narasim...@gmail.com> wrote:
> 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
Hello,
here is the while loop piece of code that works now.
b=0
k=1
while (b+k lt nb) do begin
if finite(ndvislice[s,b+k]) eq 0 or finite (ndsislice[s,b+k]) eq 0
then begin
ndvi[s,b+k]=mask[s,r]
ndsi[s,b+k]=mask[s,r]
k=k+1
endif else begin
if (ndvislice[s,b+k] lt ndvislice[s,b])then begin;
ndvi[s,b+k]=mask[s,r]
ndsi[s,b+k]=mask[s,r]
k=k+1
endif else begin
ndvi[s,b+k]=ndvislice[s,b+k]
ndsi[s,b+k]=ndsislice[s,b+k]
b=b+k
k=1
endelse
endelse
endwhile
So, with two conditions, i can change the number of bands (b) or i can
change the counter (k) depending on which condition is satisfied
during an iteration. Although it works, it does take some time which
might suggest that an array oriented code might work faster. But
anyway, it works.
Thanks!
Raghu
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