Sorry about the separate post about this, but I suspect the answer to this question might actually be "no", at least in the Linux version. The share/proj directory in FWTools is lacking a "null" executable. Since the "proj-datumgrid-1.4.tar.gz" download contains a ".lla" file for all of the other grids present (conus, hawaii, stgeorge, etc), as well as a "null.lla" file, I assume that the lack of a "null" executable implies that proj was built without this grid-shift file.<br>
<br>If someone else more knowledgeable about proj could confirm this for me, I would appreciate it.<br><br>Roger<br>--<br><br><div class="gmail_quote">On Mon, Oct 20, 2008 at 7:11 PM, Roger André <span dir="ltr"><<a href="mailto:randre@gmail.com">randre@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Thanks Frank,<br><br>I'm trying to narrow down the problems I'm having with a projection, and that "+nadgrids=@null" parameter is new to me. Someone told me that I might need to install a separate set of files to enable it. Just wanted to check and make sure.<br>
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--</font><div><div></div><div class="Wj3C7c"><br><br><div class="gmail_quote">On Mon, Oct 20, 2008 at 8:01 PM, Frank Warmerdam <span dir="ltr"><<a href="mailto:warmerdam@pobox.com" target="_blank">warmerdam@pobox.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>Roger André wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Is it possible in FWTools to use a projection which specifies the following, "+nadgrids=@null"?<br>
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Roger,<br>
<br>
Yes, it should work with the FWTools PROJ.4 tools (and related stuff<br>
like MapServer). If you want to use it with GDAL and OGR it is a bit<br>
more involved. I think you need to add +wktext in the PROJ.4 definition<br>
so that GDAL will "capture" the literal PROJ.4 definition in the internal<br>
WKT representation so the nadgrids part won't get lost.<br>
<br>
Best regards,<br><font color="#888888">
-- <br>
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I set the clouds in motion - turn up | Frank Warmerdam, <a href="mailto:warmerdam@pobox.com" target="_blank">warmerdam@pobox.com</a><br>
light and sound - activate the windows | <a href="http://pobox.com/%7Ewarmerdam" target="_blank">http://pobox.com/~warmerdam</a><br>
and watch the world go round - Rush | Geospatial Programmer for Rent<br>
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