<p dir="ltr">Try to leave out the -r option in invproj: the output of proj, that you feed into invproj is not in reverse order.</p>
<p dir="ltr">Also, do not expect identical output, especially not for data points far off the central meridian.</p>
<p dir="ltr">/Thomas</p>
<div class="gmail_quote">Den 16. maj 2016 19.26 skrev "Dean Schulze" <<a href="mailto:dschulze@wirelessseismic.com">dschulze@wirelessseismic.com</a>>:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Following the example in the man page if I do<br>
<br>
proj +proj=utm +lon_0=112w +ellps=clrk66 -r man.page.lat.lon.txt<br>
<br>
where the file man.page.lat.lon.txt contains<br>
<br>
45d15'33.1" 111.5W<br>
45d15.551666667N -111d30<br>
+45.25919444444 111d30'000w<br>
<br>
I get the 3 lines of output shown in the man page:<br>
<br>
460769.27 5011648.45<br>
460769.27 5011648.45<br>
460769.27 5011648.45<br>
<br>
So far, so good. But when I try to use invproj to get back the original inputs the results are not even close to the inputs:<br>
<br>
proj +proj=utm +lon_0=112w +ellps=clrk66 -r man.page.lat.lon.txt | invproj +proj=utm +lon_0=112w +ellps=clrk66 -r<br>
<br>
gives<br>
<br>
73d25'28.89"W 3d18'2.678"N<br>
73d25'28.89"W 3d18'2.678"N<br>
73d25'28.89"W 3d18'2.678"N<br>
<br>
What is invproj giving me? How do I run invproj to get back my original inputs?<br>
<br>
Apparently invproj doesn't use command line parameters the same way that proj does. Is this documented somewhere? I've read the 3 .pdfs provides as users manuals, but they say nothing about how to use invproj to get back the original inputs.<br>
<br>
Thanks.<br>
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</blockquote></div>