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the isnumeric function and the NaN

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Snoopy
Snoopy on 7 Sep 2018
Edited: Snoopy on 7 Sep 2018
I have a matrix array (A) that includes three column arrays. All columns contain integers except that one of the columns also include NaNs. When I type isnumeric(A), the output is a logical value 1. Apparently NaN is recognised as a numeric entry as otherwise MATLAB would return a logical value of 0. How is a NaN recognised exactly?
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Stephen23
Stephen23 on 7 Sep 2018
Edited: Stephen23 on 7 Sep 2018
@Snoopy: The behavior of NaN's within MATLAB operations is explained here:
NaN's are just a particular bit pattern that is assigned to have the value Not-a-Number. To know more about the classes that support NaN's, you need to read about IEEE 754 standard (the well-supported 1985 version), which defines the floating point numbers that MATLAB uses:
This also explains how the numbers are stored, including the "special" values like Inf and NaN:
Snoopy
Snoopy on 7 Sep 2018
Edited: Snoopy on 7 Sep 2018
This is it. Thanks for the effort and time put into the answer. I wanted to accept this as answer but it seems comment cannot be marked as such. Sorry for this.

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Answers (1)

Cesar Antonio Lopez Segura
Hi,
Write this in your command window:
isnan( [ 0 1 NaN] )

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