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Re: Flaw found in histogram on Red Hat Linux

this program ran with not a problem on Win NT WS4.0 SP5, with IDL 5.2.1.
(i.e. no "corrupt array descriptor")

bob stockwell
stockwell at co-ra dot com

<grunes@yahoo.com> wrote in message 8i8im3$8u2$1@nnrp1.deja.com">news:8i8im3$8u2$1@nnrp1.deja.com...
> Under some conditions, the histogram function causes IDL
> to crash with a corrupt array descriptor.  I was unable to
> duplicate the error on other platforms with older versions
> of IDL and PV-WAVE.
> I would be curious to know if anyone could test this on
> a version of PV-WAVE for Linux, or on recent versions of
> IDL on other platforms.
> ---------Begin Included Program----------
> ; Attempt by mitch grunes to make IDL histogram fail
> ;  with a corrupt array descriptor.
> ; The failure is noted on Red Hat Linux 6.0 or Mandrake
> ; Linux 7.1 with IDL 5.2 or 5.3.
> ;=========Subroutine==========
>   pro test1,a
>   bot=min(a)
>   top=max(a)
>   bin=(top-bot)/4000
>   hist=histogram(a,min=bot,max=top,bin=bin)
>   end
> ;=========Main Program=========
>   for i=0,1000 do begin
>     print,i
>     a=randomu(seed,1540,704)
>     test1,a
>   endfor
>   end
> ----------End Included Program----------
> I was able to get around the error by bumping top up a
> little, but that seems unsatisfactory.
> (I have noted in the past that histogram returned
> incorrect values [total of histogram does not equal
> # of elements] when handling arrays on the order
> of 100,000,000 elements, as though they maybe used
> floating point counters instead of integral.
> I think it may have been implemented a bit sloppily
> in general.)
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> Before you buy.