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<TITLE>RE: [fdo-internals] RFC 11 has been posted</TITLE>
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<P DIR=LTR><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">Hi,</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">Frank</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">, I think it</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">’</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">s kind of confusing</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">for the user</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">having</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">3 flavors</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> (and not standard)</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">.</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">I</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">guess we</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">’</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">ll be better off</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"></FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">to</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">relate</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">the</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">length calculation to what Oracle does</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">:</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">- </FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">SDO_LENGTH()</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">may</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> take a parameter which specif</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">ies</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> the</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">desired</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">dimensionality.</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"></FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">Which makes me think that</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">our Length() should do the same</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> and it s</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">hould d</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">efault to 2D.</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">But</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">say</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">in the case of a pipe</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">that</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> goes up and down</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">by</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">ignoring Z</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">the</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> results</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> are pretty much wrong</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">. Orest suggested a Length3()</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> function. In either case, we should implement both</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> now</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">.</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">- </FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">The length is in meters for geodetic data. W</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">ould it be reasonable to implement the conversion</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">to XYZ</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">given the spheroid parameters listed in the WKT?</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"></FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">Algorithms are</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">available</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">. (</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">Please n</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">ote</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">I</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">’</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">m</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> not suggesting to introduce proj</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">ection support).</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<UL DIR=LTR><UL DIR=LTR>
<P DIR=LTR><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">T</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">his</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">point conversion utility</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">can be either a</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">simple function or the default implementation of an interface</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> for the</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> case the FDO user</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">prefers</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"> to override i</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">t</FONT></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas">. Or better yet,</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">implement a</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">virtual</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">method to</FONT></SPAN><SPAN LANG="en-us"> <FONT COLOR="#000000" FACE="Consolas">return the distance between 2 points?</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
</UL></UL>
<P DIR=LTR><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Calibri">Thanks,</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Calibri">Dan.</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT COLOR="#000000" FACE="Consolas"></FONT></SPAN><SPAN LANG="en-us"> </SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">-----Original Message-----<BR>
From: fdo-internals-bounces@lists.osgeo.org [<A HREF="mailto:fdo-internals-bounces@lists.osgeo.org">mailto:fdo-internals-bounces@lists.osgeo.org</A>] On Behalf Of Frank Warmerdam (External)<BR>
Sent: Saturday, September 08, 2007 3:46 PM<BR>
To: FDO Internals Mail List<BR>
Subject: Re: [fdo-internals] RFC 11 has been posted</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">Orest Halustchak wrote:</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> Hi Frank,</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> </FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> Adding projection support to FDO hasn't been on the radar screen (at</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> least any that I've seen). Focus so far has been on keeping FDO as the</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> basic data access layer that does not try to modify the data going in or</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> coming out. Projection operation or other data modification (e.g.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> converting arcs to polylines) is being done at a higher level.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> </FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> Do we want to change this? If we want to discuss this, then this is the</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> right forum in which to do that, but I'd like to decouple it from the</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> RFC 11 discussion. I'd like to come up with an approach to add area and</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> length support if possible within the current framework of what fdo does</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">> and have the projection discussion separately.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">Orest / others,</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">Agreed. Whether or not to introduce projections support within FDO itself</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">is essentially unrelated to RFC 11. But the lack of it at this time implies</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">we can't really provider provider implementors utility functions to compute</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">linear results for length and area as has been suggested.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">Given that assumption, would it be reasonable for RFC 11 to address providers</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">indicating what results are returned? Or perhaps we could have:</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">LengthCartesian()</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">LengthMetric()</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">and Length()</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">with LenthCartesian() (if available) doing the obvious cartesian computation,</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">LengthMetric() returning a result in meters and Length() doing either with</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">no apriori definition of which will be done. Would this approach be reasonable?</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">Best regards,</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">-- </FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">---------------------------------------+--------------------------------------</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">I set the clouds in motion - turn up | Frank Warmerdam, warmerdam@pobox.com</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">light and sound - activate the windows | <A HREF="http://pobox.com/~warmerdam">http://pobox.com/~warmerdam</A></FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">and watch the world go round - Rush | President OSGeo, <A HREF="http://osgeo.org">http://osgeo.org</A></FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Consolas">_______________________________________________</FONT></SPAN></P>
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