<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; ">Paul, <div><br></div><div>You're totally right. Sorry for the segue. If I have meters, I can rely on that and code accordingly. </div><div><br></div><div>Thanks,</div><div>Jeff.</div><div><br><div><div>On Oct 12, 2009, at 10:13 AM, Paul Ramsey wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div>On Mon, Oct 12, 2009 at 10:05 AM, Jeff Hamann<br><blockquote type="cite">having very familiarity with how this might be accomplished, I can envision<br></blockquote><blockquote type="cite">the following examples:<br></blockquote><blockquote type="cite">st_area( boundary, 'hectares')<br></blockquote><blockquote type="cite">where boundary is from a google earth file (WGS84)<br></blockquote><blockquote type="cite">st_buffer( stream, stream_buffer[1], 'feet' )<br></blockquote><blockquote type="cite">where stream is in UTM (meters), stream buffer vector is in feet, and the<br></blockquote><blockquote type="cite">resulting buffer area needs to be reported in acres or hectares.<br></blockquote><br>As Regina pointed out, this conversation can segue very quickly from a<br>specific "what should geography do" question into a larger "what<br>should geometry and geography do" place. Supporting arbitrary output<br>units in geometry involves a great deal more new machinery than doing<br>it for geography (because the geometry is currently blissfully unaware<br>of what SRS it is in, except for the SRID number).<br><br>Geography, on the other hand, is already returning all answers in<br>metres, so supporting other units is "just" a matter of providing a<br>lookup table and mechanisms for parsing the string inputs of unit<br>names.<br><br>I think I'm going to err on the side of simplicity right now, which is<br>just return metres, since the story is so simple: we return metres. If<br>you want something else, scale appropriately.<br><br>P.<br></div></blockquote></div><br><div>
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: 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; "><div>Jeff Hamann, PhD<br>PO Box 1421<br>Corvallis, Oregon 97339-1421<br>541-754-2457<br>jeff.hamann[at]forestinformatics[dot]com<br><a href="http://www.forestinformatics.com/">http://www.forestinformatics.com</a></div></span>
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