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Re: Cannot understand a part of the IDL routine!! pls help!! [message #71063 is a reply to message #70925]

Sun, 23 May 2010 09:07

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

bala murugan writes:

> The following is a part of the IDL routine for region grow. The
> following three lines of code is used to define the pixels that is the
> ROI pixels.
> x = FINDGEN(16*16) MOD 16 + 276
> y = LINDGEN(16*16) / 16 + 254
> roiPixels = x + y * imgDims[0]
>
> The question is how does it define the ROI pixels?
> I dont see how it does........ Somebody please help me by giving a
> simple and clear description.

What is happening here is the IDL is turning one-dimensional
image indices into two-dimensional image indices. Before
the advent of the function Array_Indices, we always had
to do this by hand. This code was obviously written in
those long-ago dark days.

Here is an article that explains this process in some
detail:

http://www.dfanning.com/tips/where_to_2d.html

Cheers,

David

--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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[Message index]

		Cannot understand a part of the IDL routine!! pls help!! By: bala murugan on Fri, 21 May 2010 14:33
		Re: Cannot understand a part of the IDL routine!! pls help!! By: Brian Daniel on Tue, 25 May 2010 12:16
		Re: Cannot understand a part of the IDL routine!! pls help!! By: Brian Daniel on Tue, 25 May 2010 12:13
		Re: Cannot understand a part of the IDL routine!! pls help!! By: Jeremy Bailin on Wed, 26 May 2010 05:51
		Re: Cannot understand a part of the IDL routine!! pls help!! By: Jeremy Bailin on Tue, 25 May 2010 06:23
		Re: Cannot understand a part of the IDL routine!! pls help!! By: Brian Daniel on Mon, 24 May 2010 11:26
		Re: Cannot understand a part of the IDL routine!! pls help!! By: Jeremy Bailin on Mon, 24 May 2010 05:16
		Re: Cannot understand a part of the IDL routine!! pls help!! By: David Fanning on Sun, 23 May 2010 09:07

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