| Re: WHERE approaching Flatland [message #34083] |
Wed, 19 February 2003 04:50 |
Haje Korth
Messages: 651
Registered: May 1997
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Senior Member |
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I always use the function WHERETOMULTI below. (Sorry about the line spacing)
Haje
;************************ Beginning of wheretomulti.pro
************************
PRO WhereToMulti, Array, Indices, Col, Row, Frame
;+
; NAME: wheretomulti.pro
;
; FUNCTION: Convert WHERE output to 2d or 3d indices
;
; USAGE: WhereToMulti, Array, Indices, Col, Row, Frame
;
; INPUT ARGUMENTS:
; Array: the array that was WHERE'd
; Indices: the indices returned by WHERE
;
; OUTPUT ARGUMENTS:
; Col: Indices to first dimension.
; Row: Indices to second dimension.
; Frame: Indices to third dimension. Returned only for 3-d array.
;
; OPTIONAL ARGUMENTS:
;
; KEYWORDS:
;
; REQUIRED MODULES:
;
; SIDE EFFECTS:
;
; ERROR HANDLING:
; If Array is not a vector or matrix, all return values are set to zero
; and a message is written to the screen.
;
; NOTES:
;
; HISTORY:
; 1998 Sept 15 J.L.Saba Developed based on code from David Fanning's
; web site.
;
;- End of
prologue ------------------------------------------------------------ -
s = SIZE ( Array )
NCol = s[1]
Col = Indices MOD NCol
IF s[0] EQ 2 THEN BEGIN ; 2-d array
Row = Indices / NCol
ENDIF ELSE IF s[0] EQ 3 THEN BEGIN ; 3-d array
NRow = s(2)
Row = ( Indices / NCol ) MOD NRow
Frame = Indices / ( NRow * NCol )
ENDIF ELSE BEGIN ; neither 2d or 3d
Col = 0
Row = 0
Frame = 0
PRINT, 'WhereToMulti called with bad input. Array not a vector or matrix.'
HELP, Array
ENDELSE
RETURN
END
;*************************** End of wheretomulti.pro
***************************
--
Dr. Haje Korth
Space Physics Group
The Johns Hopkins University
Applied Physics Laboratory
MS MP3-E128
11100 Johns Hopkins Road
Laurel, MD 20723-6099
USA
Phone: 240-228-4033 (Washington), 443-778-4033 (Baltimore)
Fax: 240-228-0386 (Washington), 443-778-0386 (Baltimore)
"Sean Raffuse" <sean@me.wustl.edu> wrote in message
news:b2u1d0$1nc$1@newsreader.wustl.edu...
> Hello,
>
> Is there are 2-d version of where?
>
> I would like to do this:
>
> bad = where(Array[*,*,0] GT Array[*,*,5])
>
> Array[bad,1:5] = Array[bad,0]
>
> I know that doesn't work, but after having spent some time with IDL, I'm
> allergic to loops.
>
> Thanks in advance,
>
> Sean
>
>
>
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| Re: WHERE approaching Flatland [message #34090 is a reply to message #34083] |
Tue, 18 February 2003 13:48  |
Wonko[3]
Messages: 9
Registered: February 2003
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Junior Member |
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sean@me.wustl.edu (Sean Raffuse) wrote:
> Is there are 2-d version of where?
> I would like to do this:
> bad = where(Array[*,*,0] GT Array[*,*,5])
> Array[bad,1:5] = Array[bad,0]
I do these things like this:
xy = (size(Array,/dim))[0] * (size(Array,/dim))[1]
for i = 1, 5 do Array[ bad + i*xy ] = Array[bad]
> I know that doesn't work, but after having spent some time with IDL,
> I'm allergic to loops.
Ummm... this should work:
n = n_elements( bad )
Array[ rebin(bad,n,5) + transpose(rebin((lindgen(5)+1)*xy,5,n)) ] =
rebin( array[bad], n, 5 )
Alex
--
Alex Schuster Wonko@wonkology.org PGP Key available
alex@pet.mpin-koeln.mpg.de
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| Re: WHERE approaching Flatland [message #34094 is a reply to message #34090] |
Tue, 18 February 2003 12:15 |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Sean Raffuse (sean@me.wustl.edu) writes:
> Is there are 2-d version of where?
>
> I would like to do this:
>
> bad = where(Array[*,*,0] GT Array[*,*,5])
>
> Array[bad,1:5] = Array[bad,0]
>
> I know that doesn't work, but after having spent some time with IDL, I'm
> allergic to loops.
I think maybe you want to re-read that thread from a week
or so ago, entitled "Interesting Where Function Gotcha".
Cheers,
David
--
David W. Fanning, Ph.D.
Fanning Software Consulting, Inc.
Phone: 970-221-0438, E-mail: david@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155
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