Re: [alma-sw-ssr] Offline Requirements v3.1

[Bryan Butler <bbutler@cv3.cv.nrao.edu>]

On 2001.08.21 22:11 Steven T. Myers wrote:
> 
> The current req text reflects what I thought we had decided (though the
> parenthetical Comment may not) - it is allowed, for nominal cost.  I would
> say an IDL liscense as it stands is more than "nominal".  My experience
> (with MATLAB and IDL) is that you take a tremendous performance hit
> using these packages, one I doubt we can afford given the processing
> requirements.  

i can confirm this.  i did detailed tests of this a few years ago when
simulating holography errors - i.e., lots of FFT/DFTs.  the difference
between optimized FORTRAN and IDL implementations was about a factor of
20 in speed.  you can see more details at:
http://www.aoc.nrao.edu/~bbutler/work/nraomemos/holo_sim.ps.gz
if you want (see table 1).

while packages like IDL and matlab are very nice when visualizing things,
and for smaller problems, they just cannot deliver the speed we will need
(in my experience/opinion) for ALMA data processing.

> However, if it meets the benchmark specs (tbd) and the
> rest then it would pass of course.
> 
> We may wish to dodge the question entirely by deleting this requirement
> (OL-1.2-R6), though personally I think it is fine as-is.
> 
> On Tue, 21 Aug 2001, Steve Scott wrote:
> 
> >
> > Excellent point. The requirement doesn't seem to reflect the Berkeley
> > discussion as I recall it. IMHO, commercial software should be an option
> > (even if it costs more than "nominal") unless, of course, the ASAC
> > mandates otherwise. It seems like there are quite a few options
> > available for smaller institutions, including reducing data remotely at
> > one of the regional data centers.
> >
> > Steve
> >
> >
> > mel wright 456 wrote:
> > >
> > > 2. A lot of people using IDL or matlab in preference
> > > to custom-built software. Should we re-visit OL-1.2-R6 ?
> > >
> > > Melvyn
> >
> 
> -- 
> 
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> |:| Steven T. Myers                      |:|  Associate Scientist      |:|
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>