| Re: Manipulation using where [message #53100 is a reply to message #53099] |
Wed, 21 March 2007 07:41   |
Vidhya
Messages: 6
Registered: October 2006
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Junior Member |
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Hi David,
But the problem, I have the row which have an alternate values of zero
and some integers.
0 25695 0 25966 0
27235 0 37145 0 94282
0........... something like this!
So couldnt find with total of all the column elements.
So I tried to specify as to where there are zero.
Any suggestions?
On 21 Mar, 15:19, David Fanning <n...@dfanning.com> wrote:
> Vidhya writes:
>> I have an image, SUBIMAGE LONG = Array[372, 374, 62] and I
>> would like to find all the values equal to zero (basically missing
>> lines/rows). Right, done using
>
>> z = where(subimage(*,*,*) EQ 0, count)
>
>> The result is one-dimensional array: LONG = Array[15457]
>
>> now I would like perform an operation trying to find which row there
>> are in, and find the averages of the rows above and below and
>> replacing them for those found zero values.
>
>> How do I go about this?
>
>> I tried using array_indices, but its bit confusing.
>
> I think you are going about this in the wrong way.
> If a row is missing, all the column values in that
> row are zero. Thus, if you totaled your array over
> the column dimension, you would find the locations
> where all the columns values were zero, since these
> would be zero.
>
> Consider a simple example.
>
> a = Indgen(4, 5, 3)
> a[*,2,1] = 0
> Print, a
> 0 1 2 3
> 4 5 6 7
> 8 9 10 11
> 12 13 14 15
> 16 17 18 19
>
> 20 21 22 23
> 24 25 26 27
> 0 0 0 0
> 32 33 34 35
> 36 37 38 39
>
> 40 41 42 43
> 44 45 46 47
> 48 49 50 51
> 52 53 54 55
> 56 57 58 59
>
> t = Total(a, 1) ; Total over columns
> Print, t
> 6.00000 22.0000 38.0000 54.0000 70.0000
> 86.0000 102.000 0.000000 134.000 150.000
> 166.000 182.000 198.000 214.000 230.000
>
> index = Where(t EQ 0)
> rowframe = Array_Indices(Size(t,/Dim), index, /Dim)
> row = rowframe[0] & frame = rowframe[1]
> Print, row, frame
> 2 1
>
> So, you know that all the column values in row 2, frame 1
> are zero. Now you can do whatever you like with that
> information. :-)
>
> 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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