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Re: (long) sNaNs not what they could be...



Dan, Lee, and all,

On Oct 15, 2010, at 7:17 PM, Lee Winter wrote:

> On Fri, Oct 15, 2010 at 6:01 PM, Dan Zuras Intervals
> <intervals08@xxxxxxxxxxxxxx> wrote:
>> 
>>        Still, some enterprising compiler writer or debugger
>>        writer out there COULD do something along these lines.
>>        It wouldn't buy them much but it would be interesting.
> 
> What you have described is why SNaNs are not particularly useful as a
> memory initializer.  But AFAICT none of the above reasons indicate
> that SNaNs are inappropriate or ineffective for constructing FP
> variables.  I intend to continue offering them as a non-default
> option.  Did I miss something?

I TRY, in my Matlab code, to allocate and (not) initialize arrays as
    A = NaN * ones(...);
especially when I will be filling in A by chunks.  The practice has made obvious errors in logic more times than I should admit :-)

I had thought that was a reasonable thing to do.  Now I have a much better idea WHY.

Dr. George F. Corliss
Electrical and Computer Engineering
Marquette University
P.O. Box 1881
1515 W. Wisconsin Ave
Milwaukee WI 53201-1881 USA
414-288-6599; GasDay: 288-4400; Fax 288-5579
George.Corliss@xxxxxxxxxxxxx
www.eng.mu.edu/corlissg