<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><div>On Dec 1, 2011, at 6:00 PM, Paul Ramsey wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>On Mon, Nov 28, 2011 at 9:45 AM, Olivier Courtin<br><<a href="mailto:olivier.courtin@oslandia.com">olivier.courtin@oslandia.com</a>> wrote:<br><blockquote type="cite"><br></blockquote><blockquote type="cite">On Nov 28, 2011, at 6:38 PM, Paul Ramsey wrote:<br></blockquote><blockquote type="cite"><blockquote type="cite">One way to ensure consistency would be to make<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">the GBOX actually be float (GBOXF). I recall you were very happy to<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">have GBOX replace BOX2FLOAT4. Was that because GBOX is higher<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">dimensional or because it is double based, or both?<br></blockquote></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">Both in fact,<br></blockquote><blockquote type="cite">As double bbox are really convenient as our datas are double based.<br></blockquote><br>What aspect (aside from dimensionality) of the float box was problematic?<br></div></blockquote></div><div apple-content-edited="true"><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; "><div><br></div><div>I see now only 3 points, and all minors indeed:</div><div><br></div><div>1) You avoid all 'stuff' related to double to float conversion.</div><div><br></div><div>2) Upon platform float bbox values could be slightly differents,</div><div> (with real world datas) so unit tests them could be more painfull than double.</div><div> (at least with old unit tests, could be done in a more comprehensive way</div><div> now with cunit)</div><div><br></div><div>3) On a user point of view it looks like 'loosing' precision on the bbox </div><div> enclosing your datas (meaningfull only with geocentric datas on high scales).</div></span></div><div apple-content-edited="true"><br></div><div apple-content-edited="true">On the other hand, i don't have any metric on the performance overhead to switch from float to double, on a large dataset.</div><div><div><br></div><div><br></div><div><br></div><div>So my primary concern on this point is consistency, </div><div>rather than double vs float.</div><div><br></div><div>--</div></div><div>Olivier</div></body></html>