comp.lang.idl-pvwave archive: archive » IDL Average Value Graphs

Home » Public Forums » archive » IDL Average Value Graphs

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: IDL Average Value Graphs [message #61501 is a reply to message #61413]

Thu, 17 July 2008 14:52

Jean H.
Messages: 472
Registered: July 2006

Senior Member

> I needed the 2d coordinates because I'm dealing with FITS images, so I
> need to grab the value of each of the pixels in a given region, unless
> I'm missing an easier way to do this.

I am not familiar with FITS images, but I strongly believe you are
missing an important IDL feature.
Read the help file under "Understanding Array Subscripts "

**************
Elements of multidimensional arrays also can be specified using only one
subscript, in which case the array is treated as a vector with the same
number of points.
A0,0 A0,1
A0,1 A1,1
A0,2 A1,2
In the 2 by 3 element array, A, element A[2] is the same element as A[0,
1], and A[5] is the same element as A[1, 2].
***************
>
I have one more question about POLYFILLV. If a line goes
> through a pixel, does it not include this pixel in the region? Does
> it include it if it is more than half way inside the region? If so,
> what happens to perfectly split pixels?
>
> Thanks a lot for the help,
> Andy

the algorithm used is a bit fuzzy.... people, including myself, often
complain here that some pixels get selected while other do not (make a
few tests). As David mentioned, IDLgrROI provides better results. Now it
all depends on what you are doing... if you select a few 100 000 pixels,
you might not care that much about having a few extra/missing pixels!

Jean

Report message to a moderator

[Message index]

		IDL Average Value Graphs By: andybohn on Tue, 15 July 2008 13:51
		Re: IDL Average Value Graphs By: David Fanning on Thu, 17 July 2008 08:33
		Re: IDL Average Value Graphs By: andybohn on Thu, 17 July 2008 10:55
		Re: IDL Average Value Graphs By: Jeremy Bailin on Wed, 16 July 2008 11:18
		Re: IDL Average Value Graphs By: andybohn on Thu, 17 July 2008 18:11
		Re: IDL Average Value Graphs By: David Fanning on Thu, 17 July 2008 16:02
		Re: IDL Average Value Graphs By: Jean H. on Fri, 18 July 2008 10:20
		Re: IDL Average Value Graphs By: Jean H. on Thu, 17 July 2008 14:52
		Re: IDL Average Value Graphs By: David Fanning on Thu, 17 July 2008 12:09
		Re: IDL Average Value Graphs By: andybohn on Thu, 17 July 2008 11:02

Previous Topic:	Something Has Changed
Next Topic:	QHULL/VORONOI question

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Sat Oct 18 04:46:17 PDT 2025

Total time taken to generate the page: 0.56213 seconds