Clear Filters
Clear Filters

the isnumeric function and the NaN

34 views (last 30 days)
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?
  6 Comments
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.

Sign in to comment.

Answers (1)

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

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!