Hi Bryan-
> Date: Thu, 21 Dec 2006 17:06:23 +0000
> From: Bryan Lawrence <b.n.lawrence at rl.ac.uk>
> Subject: Re: [CF-metadata] attributes for min/max data values for
> visualization
> To: Steve Emmerson <steve at unidata.ucar.edu>
> Cc: cf-metadata at cgd.ucar.edu
> Message-ID: <1166720783.4769.61.camel at localhost.localdomain>
> Content-Type: text/plain
>
>
> Steve is so right!
>
> The ozone hole was ignored for years because someone decided to omit
> non-sensible values: the problem is that the folk who choose "sensible"
> don't choose the colour scale at the viz end ... so you can't rely on
> undershoots and overshoots being obvious to the end-user at first
> parse... here be dragons!
>
> A safe alternative which might save time in visualising large datasets
> would be for the *actual* minimum and maximum to be optionally stored as
> attributes somehow ... this would be very useful for data mining as well
> as visualisation ...
This is what I would like to see - the actual minimum and maximum
values for the dataset as optional attributes for the variables.
The problem we face now is having to read the data to determine
this. If we had the attributes available, we could circumvent that.
As an aside, the IDV assigns the ends of the
color table to values outside the range of the color table, so
values are always colored. You can optionally set the range
of the displayed data, so values outside that range would show
up as "holes".
Don
*************************************************************
Don Murray UCAR Unidata Program
dmurray at unidata.ucar.edu P.O. Box 3000
(303) 497-8628 Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
*************************************************************
Received on Fri Dec 22 2006 - 06:51:42 GMT
