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Re: pointer problems [message #66467 is a reply to message #66274]

Thu, 07 May 2009 20:02

R.G. Stockwell
Messages: 363
Registered: July 1999

Senior Member

<tkg@lanl.gov> wrote in message
news:e7dfb99c-91cd-483f-93ba-9e13c31f659a@y33g2000prg.google groups.com...
>
>
> I'm trying to store an array of pixel xy indicies for later output to
> a text file. The number of xy pairs is different for each array
> element. I'm trying to use pointers to do this with the following
> code snippet:
>
> xy = ptrarr(npixels, /ALLOC)
>
> for ipixel = 0, npixels - 1 do begin
>
> ; much snipped code
>
> indi = where(superMask ne 0, count)
>
> if (count gt 0) then *xy[ipixel] = array_indices(superMask,
> indi)
>
> ; more snipped code
>
> endfor

You need an else branch to assign the values of
*xy in the case where count is = 0.

Or else, accessing xy in the future can result in
"variable is undefined" error messages.

cheers,
bob

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[Message index]

		pointer problems By: tkg on Thu, 07 May 2009 11:55
		Re: pointer problems By: R.G. Stockwell on Fri, 08 May 2009 11:20
		Re: pointer problems By: tkg on Fri, 08 May 2009 05:10
		Re: pointer problems By: R.G. Stockwell on Thu, 07 May 2009 20:02

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