| coherence.pro re-re-post (ignore previous re-post) [message #15416] |
Thu, 13 May 1999 00:00  |
Dick Jackson
Messages: 347
Registered: August 1998
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Senior Member |
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(now attaching it *after* changing the Windows settings... sorry, folks!)
Hi again,
eddie haskell wrote:
>
> Dick,
> [...]
> As an aside, I had a difficult time extracting the code you attached to
> your post. It could easily be my news reader but if others are using
> similar readers and you have other options for attachments, ...
Thanks for letting me know (*blush!*). If this attachment works better, then
my lesson for the day is that in Windows File Types Options panel
(accessible in Windows Explorer/View/Options...) the IDL source file should
have Content Type (MIME): text/plain. Thanks to Dave Foster (who knows how
to attach a file!) for the good example.
Cheers,
--
-Dick
Dick Jackson Fanning Software Consulting, Canadian Office
djackson@dfanning.com Calgary, Alberta Voice/Fax: (403) 242-7398
Coyote's Guide to IDL Programming: http://www.dfanning.com/
FUNCTION coherence, array, width
;; Returns 'coherence' matrix from 2D input array.
;; Each element in the result is the Std. Dev. of the
;; 'width' x 'width'-pixel neighborhood from the original image.
;; Dick Jackson, Fanning Software Consulting
;; djackson@dfanning.com
size = Size(array, /Dimensions)
IF N_Elements(size) NE 2 THEN $
Message, 'Input array must be 2-dimensional.'
nx = size[0]
ny = size[1]
IF nx LT 3 OR ny LT 3 THEN $
Message, 'Input array must have at least 3 rows and 3 columns.'
IF N_Elements(width) EQ 0 THEN width = 3
; Make Sum-of-X array (sx) where each element contains the sum of
; values from the neighborhood of the original array.
kernel = Replicate(1, width, width) ; kernel for convolution to simply
; sum all values with equal weight
sx = Convol(Float(array), kernel)
; Make Sum-of-X-squared array (sx2) where each element contains the sum of
; *squared* values from the neighborhood of the original array.
sx2 = Convol(array ^ 2.0, kernel)
; Calculate, for each pixel, the standard deviation of the set of
; the neighborhood values:
; SD = Sqrt((Sum(X^2) - (Sum(X)^2 / n)) / (n-1))
n = width ^ 2.0
Return, Sqrt((sx2 - (sx^2 / n)) / (n-1))
END ;; coherence
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| Re: coherence.pro re-re-post (ignore previous re-post) [message #15453 is a reply to message #15416] |
Tue, 18 May 1999 00:00  |
eddie haskell
Messages: 29
Registered: September 1998
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Junior Member |
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Dick Jackson wrote:
> (now attaching it *after* changing the Windows settings...
Third time's a charm! ;-)
Cheers,
eddie
----- ---- --- --- ---- --- -- --- --- -- -- - - - -
|\ A G Edward Haskell
|\ Center for Coastal Physical Oceanography
|\ Old Dominion University, Norfolk VA 23529
|\ Voice 757.683.4816 Fax 757.683.5550
|\ e-mail haskell*ccpo.odu.edu
----- ---- --- ---- --- --- --- --- -- -- -- - - - -
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