On Sep 5, 2009, at 11:27 AM, Roger Hui wrote:

> NO DATA, like NaN, should be treated with caution.
> For example, what are the answers to the following
> questions?

I'm sorry that I didn't answer your questions in my previous reply.   
The following are my suggestions:

> NODATA = NODATA

1

> NODATA = 314159

0

> NODATA ~: NODATA

0

> NODATA > NODATA

Domain error

> $ NODATA

NODATA

> 3 $ NODATA

NODATA NODATA NODATA

> NODATA $ 3

NODATA

> 3+NODATA

NODATA

> 0 1 2,NODATA

0 1 2 NODATA

> /: 0 1 2,NODATA

Domain error (applying an comparison operator between NODATA and any  
other kind of value results in a Domain error).  As a special case,  
NODATA ==


> < NODATA

+--------+
| NODATA |
+--------+


>> NODATA

Domain error

> NODATA e. a.

0

> Last but not least,
>
> NODATA=NaN

0


----------------------------------------------------------------------
For information about J forums see http://www.jsoftware.com/forums.htm

Reply via email to