Re: http://www.ngs.noaa.gov/FGCS/BlueBook/ (fwd)

New Message Reply About this list Date view Thread view Subject view Author view

From: R Knapp (gyp_caver_at_yahoo.com)
Date: Thu Feb 07 2002 - 03:10:59 CET


Return-Path: <owner-cavexml-outgoing_at_ethz.ch>
Delivered-To: cavexml-archive_at_cartography.ch
Received: from localhost (localhost [127.0.0.1]) by karmail.ethz.ch (Postfix on SuSE eMail Server 2.0) with ESMTP id D0F139F14 for <cavexml-outgoing_at_ethz.ch>; Thu,  7 Feb 2002 03:37:17 +0100 (CET)
Received: by karmail.ethz.ch (Postfix on SuSE eMail Server 2.0, from userid 28) id 8FA039F12; Thu,  7 Feb 2002 03:37:14 +0100 (CET)
Delivered-To: cavexml_at_cartography.ch
Received: from localhost (localhost [127.0.0.1]) by karmail.ethz.ch (Postfix on SuSE eMail Server 2.0) with ESMTP id 534629F09 for <cavexml_at_cartography.ch>; Thu,  7 Feb 2002 03:37:13 +0100 (CET)
Received: from smtp013.mail.yahoo.com (smtp013.mail.yahoo.com [216.136.173.57]) by karmail.ethz.ch (Postfix on SuSE eMail Server 2.0) with SMTP id 56CD29E76 for <cavexml_at_cartography.ch>; Thu,  7 Feb 2002 03:37:08 +0100 (CET)
Received: from slip-12-64-170-164.mis.prserv.net (HELO Muphin) (12.64.170.164) by smtp.mail.vip.sc5.yahoo.com with SMTP; 7 Feb 2002 02:16:38 -0000
From: "R Knapp" <gyp_caver_at_yahoo.com>
To: "John Halleck" <John.Halleck_at_utah.edu>
Cc: "CaveXML" <cavexml_at_cartography.ch>
Date: Wed, 06 Feb 2002 21:10:59 -0500 (EST)
X-Mailer: PMMail 2.20.2370 for OS/2 Warp 4.5
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Subject: Re: http://www.ngs.noaa.gov/FGCS/BlueBook/ (fwd)
Message-Id: <20020207023708.56CD29E76@karmail.ethz.ch>
Sender: owner-cavexml_at_karmail.ethz.ch
Precedence: bulk
Reply-To: cavexml_at_cartography.ch
X-Virus-Scanned: by AMaViS perl-11


> > - Should length be metric or English? Either choice w/could incur
> > conversion back to the other "base" for misc calculations (length, depth, etc).
>
> Which English? US feet or International (ISO) feet?
> At least their is only one metric system.

True.

> (And before you think "who cares about the difference between US and ISO feet?"
> note that Larry Fish and Compass have had problems on just this issue for the people
> that need output referenced to their state plane coordinate system.)

Would the use of meters provide a solution?

> > - Should angles be degrees or radians? Radians have the advantage of being
> > friendly to computers (most functions like rads and not degrees) but again
> > there might be a conversion back for misc calculations (rose diagrams, etc).

> I'd vote degrees. My weak argument is that at least degrees can be represented
> exactly, any conversion to radians has to truncate.

Logical.

> > Maybe there could be an attribute/element that specifies this information at
> > the top of the XML file?

> As soon as it is specified at the top, then every diddly tool down the pipe has to
> be aware of it.

I think even if the canonical units will always be the same, it should be specified
somewhere, just so all tools interacting with the format can extract the correct
information without any ambiguity.

> Yep. Which is the reality. (But remember that if length A has standard deviation
> of Sa and Length be has standard deviation of Sb then the two added together have
> a standard deviation that is NOT Sa+Sb, it is sqrt (Sa*Sa+Sb*Sb).

It's been too long since I've done any real statistical anaylsis. Maybe at some point
I'll have some free time (maniacal laughter)

> I've generally not been posting things to the list, since I've come to feel that my
> pedantic picking at assumptions was inhibiting some folks from posting.

I think it has been very helpful. There is a lot of detail I would have glossed over (or
ignored until it bit me) if you didn't keep me honest. Thanks.

        Richard Knapp
        gyp_caver_at_yahoo.com


_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com


New Message Reply About this list Date view Thread view Subject view Author view

This archive was generated by hypermail 2b30 : Thu Feb 28 2002 - 23:00:00 CET