Re: ATM Plop Mirror cell optimisation

["A&S Hincks" <hincks@bigpond.net.au>]

David,

Actually, I think I might well be misunderstanding...

How do you 'rerun Plop NOT doing optimization on the largest grid' - Does
this mean that I should use the radii output from the 20 mesh ring
optimisation as the input for a further finer mesh analysis.

I am not quite sure what I need to do to run the above.

Apologies if I am a bit slow on the uptake here.

Regards

Andrew

----- Original Message -----
From: "A&S Hincks" <hincks@bigpond.net.au>
To: "david lewis" <lewis@eecg.toronto.edu>
Cc: <atm@shore.net>
Sent: Thursday, February 07, 2002 7:09 PM
Subject: Re: ATM Plop Mirror cell optimisation


> Hello David
>
> Essentially, unless I misunderstand badly (and believe me I frequently
> misunderstand :-)) I was testing what you describe below although only as
an
> end to making sure that I got the most accurate result possible.
>
> I increased the 'resolution/fineness' of the mesh with the aim of checking
> that the error decreased/tended towards to a single value. I plotted the
> results on a graph (which I can't post here) and hoped I could work out
the
> value of each support radii by visually looking at the value that the
curve
> tended to.
>
> What surprised me was that as the resolution of the mesh increased (ie 20,
> 21, 22.....n) the values of the support radii did not necessarily tend to
> any particular value.
>
> For an example of what I am talking (hopefully not babbling) about,
> referring to the (very poorly formatted) data table in my original post,
for
> support radii 4 (ie. r4), where n-mesh rings = 20, r4 = 0.757141. However
> where n-mesh rings = 40 and 41, r4 = 0.738209 and 0.743596 respectively.
>
> What I am trying to illustrate (again poorly) is that if I merely ran an
> anlalysis at n-mesh = 20 and 40, I would have thought that 0.738209 is
> closer to the optimal result. But the value n-mesh rings = 41 @ 0.743596
is
> a proportionately a rather large incremental jump back in the other
> direction.
>
> Thanks
>
> Andrew
>
>
>
> ----- Original Message -----
> From: "david lewis" <lewis@eecg.toronto.edu>
> To: <atm@shore.net>; <hincks@bigpond.net.au>
> Sent: Thursday, February 07, 2002 12:01 PM
> Subject: Re: ATM Plop Mirror cell optimisation
>
>
> >
> >
> > This is an interesting study that I've wanted to do but never bothered.
> >
> > What is interesting is if you take the result with your smallest grid,
> > which is 20, and rerun Plop NOT doing optimization on the largest
> > grid, to see what the difference in error is.
> > This will tell you how much extra error you're getting by not using the
> finest
> > grid possible.
> >
> > David Lewis
> >
>