Re: simple float/double question
Re: simple float/double question
- Subject: Re: simple float/double question
- From: Tom Sutcliffe <email@hidden>
- Date: Fri, 30 May 2003 23:34:38 +0100
NaN is a mathematical shorthand to represent things that aren't real
numbers - eg taking the square root of -1 would return NaN, because the
answer cannot be expressed without using complex numbers. Also it can
be used for the result of queries that don't make sense - eg the
arcsine of a number > 1.
It may help to consider the relationship between nil and an
instantiated object - NaN and a normal floating point value are sort of
similar.
Tom
On Friday, May 30, 2003, at 10:48 pm, Ben Dougall wrote:
On Friday, May 30, 2003, at 07:54 am, Lloyd Dupont wrote:
how to test if a float/double is a number or not ?
I mean acos(2) for example return NaN, how to know programatically
it's NaN ?
i don't understand. how can a float or a double not be a number?
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