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Re: Finding NaNs in arrays - Strange outcome [message #92383 is a reply to message #92382]

Sat, 05 December 2015 06:38

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

dmfl0590@gmail.com writes:

>
> Hello
>
> I have a 3D array A ( A FLOAT = Array[480, 480, 160]). I wanted to check for NaNs so I had split one 2D array as follows:
>
> A1 = total(A[0:79, 0:79,25])
> A2 = total(A[80:159,80:159,25])
> A3 = total(A[160:239,160:239,25])
> A4 = total(A[240:319,240:319,25])
> A5 = total(A[320:399,320:399,25])
> A6 = total(A[400:479,400:479,25])
>
> print, 'A1', A1
> print, 'A2', A2
> print, 'A3', A3
> print, 'A4', A4
> print, 'A5', A5
> print, 'A6', A6
>
> print, 'total',total(A[*,*,25])
>
> PRINT, 'sum',A1+A2+A3+A4+A5+A6
>
> I got the following print results:
> A1 682066.
> A2 1.51149e+007
> A3 9.41048e+006
> A4 9.07705e+006
> A5 1.18558e+007
> A6 62705.1
> total NaN
> sum 4.62031e+007
>
>
> Why the total(A[*,*,25]) gave me NaN? Isn't the same thing as the sum?
>
> Can anyone help with this?

The way to find NaNs in arrays is to use the Finite function:

http://www.idlcoyote.com/math_tips/nans.html

Cheers,

David

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

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[Message index]

		Finding NaNs in arrays - Strange outcome By: dmfl0590 on Sat, 05 December 2015 04:02
		Re: Finding NaNs in arrays - Strange outcome By: David Fanning on Sat, 05 December 2015 06:38
		Re: Finding NaNs in arrays - Strange outcome By: dmfl0590 on Sat, 05 December 2015 08:16
		Re: Finding NaNs in arrays - Strange outcome By: dmfl0590 on Sat, 05 December 2015 08:24
		Re: Finding NaNs in arrays - Strange outcome By: David Fanning on Sat, 05 December 2015 08:46
		Re: Finding NaNs in arrays - Strange outcome By: dmfl0590 on Sat, 05 December 2015 10:05
		Re: Finding NaNs in arrays - Strange outcome By: David Fanning on Sat, 05 December 2015 10:40
		Re: Finding NaNs in arrays - Strange outcome By: wlandsman on Sat, 05 December 2015 13:24
		Re: Finding NaNs in arrays - Strange outcome By: dmfl0590 on Mon, 07 December 2015 03:35

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