Re: isnumeric (NaN) = true !?

[Francesco Potortì]

>> What is the logic behind this:
>> 
>>      isnumeric (NaN) = 1
>> 
>> I believe that "NaN" means "not a number". How can something which is
>> "not a number" be numeric? What is the logic behind this?

"numeric" is what are numbers as far as computers are concerned.  That
is, those entities to which you apply numeric operators (addition,
multiplication and so on).  Numeric expressions are composed of numbers
and numeric operators and are evaluated to a number.

Numbers are generally stored and manipulated in IEEE representation,
which includes a given range of real numbers and some additional
entities, among which NaN, +Inf and -Inf.  For an introducion, see
 <http://en.wikipedia.org/wiki/IEEE_754-2008>.

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