From: Garry Petrie (gp_at_europa.com)
Date: Sun Feb 11 2001 - 05:16:10 CET
Received: (from mdom_at_localhost) by karto.ethz.ch (8.9.3/8.9.3/SuSE Linux 8.9.3-0.1) id FAA17593 for cavexml-outgoing; Sun, 11 Feb 2001 05:25:05 +0100 Received: from io.europa.com (IDENT:root_at_io.europa.com [216.65.131.2]) by karto.ethz.ch (8.9.3/8.9.3/SuSE Linux 8.9.3-0.1) with ESMTP id FAA17589 for <cavexml_at_cartography.ch>; Sun, 11 Feb 2001 05:25:03 +0100 Received: from europa.com (ip85.gte15.rb1.bel.nwlink.com [209.20.244.85]) by io.europa.com (8.11.1/8.11.1) with ESMTP id f1B4PnE15850 for <cavexml_at_cartography.ch>; Sat, 10 Feb 2001 20:25:49 -0800 (PST) Message-ID: <3A86120A.3030104@europa.com> Date: Sat, 10 Feb 2001 20:16:10 -0800 From: Garry Petrie <gp_at_europa.com> User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; m18) Gecko/20001108 Netscape6/6.0 X-Accept-Language: en,pdf To: cavexml_at_cartography.ch Subject: Re: defaulting units for measurements References: <Pine.GSO.4.05.10102081531270.5063-100000_at_cor.oz.cc.utah.edu> <3A83F47E.9060605_at_aic.nrl.navy.mil> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-cavexml_at_karto.baug.ethz.ch Precedence: bulk Reply-To: cavexml_at_cartography.ch
Ralph Hartley wrote:
>
> It looks like the only the way to do what needs to be done here is for
> the values of the "from" and "to" attributes to be IDREFs that
> (uniquely) identify a "station" element, that can be defined anywhere in
> the document, but might need to be defined in a particular place if it
> needs context as part of its name.
Wow, got to love it when people come to the same conclusion. Try and write a "survey
editor" using Microsoft's Access and its data forms. You build a form to enter length,
bearing, etc, but where does the station names come from? Behind the forms are tables and
you have one table for the shots and another for stations (might include cave name and x,y
and z data). You do this because shots and stations are different data, stations have
locations, but shots are relative position information. Or said another way, you can have
stations WITHOUT shots! The shot table does not contain the stations, but the indices into
the station table for lookup. It is a layer of abstraction.
John Halleck wrote:
>>>> A more fundamental approach might require use to define a list of unique
>>>> station names before listing shots!
>>>
>
> Obviously a bad idea... but it brings to mind a point:
>
> I think it would be nice if the point information had an (optional) tag
> that was a unique number. It would make some sorts of processing easier
> if there was already a number, and even easier if (in the case of N points)
> the numbers ran 1 .. N.
Sounding a little like keys into a table in a database, very good conclusion. A stations's
key would only exist for that particular version of a CaveXML file. Changing the data
after reading it and then re-writing it would of course generate a new and probably
different set of station keys.
Garry Petrie
This archive was generated by hypermail 2b30 : Thu Mar 01 2001 - 18:00:00 CET