[Proj] Running the cities example in the pdf documents gives different results

[Dean Schulze]

Ahhh, so the default ellipsoid changed from the time of writing.

Adding +ellps=clrk66 gives the same results as in the document for the first 3 cities, but the 4th city (London) is way off.  Here's my results:

  $ proj +proj=poly +ellps=clrk66 -r cities.lat.lon.txt
  # coordinates for a few cities
  -4887590.49	7317961.48 Boston, United States
  -5542524.55	6982689.05 New York, United States
  171224.94	5415352.81 Paris, France
  485359.70	5730714.96’w London, England


The document shows the following for London:

-8101.66 5707500.23 London, England

so something else is wrong.  I'm using Rel. 4.8.0, 6 March 2012.


________________________________________
From: proj-bounces at lists.maptools.org [proj-bounces at lists.maptools.org] on behalf of Jose Gonçalves [jagoncal at gmail.com]
Sent: Tuesday, May 10, 2016 2:19 AM
To: PROJ.4 and general Projections Discussions
Subject: Re: [Proj] Running the cities example in the pdf documents gives different results

Hi
You're not specifying an ellipsoid in the command line. Your PROJ version is using WGS84 by default.
The default ellipsoid of the PROJ version used in the example of the PDF document was Clarke 66.
You get those results with:
proj +proj=poly +ellps=clrk66 -r

Regards

José Gonçalves




2016-05-09 23:41 GMT+01:00 Dean Schulze <dschulze at wirelessseismic.com<mailto:dschulze at wirelessseismic.com>>:

I ran the cities example using the inputs on pg. 4 of the docs at ftp://ftp.remotesensing.org/proj/OF90-284.pdf, but I got different results than shown.  Here are the results I got:

$ proj +proj=poly -r cities.lat.lon.txt
# coordinates for a few cities
-4887445.45     7318110.56 Boston, United States
-5542376.59     6982834.25 New York, United States
171219.46       5415571.82 Paris, France
485343.33       5730932.66’w London, England


The document linked above shows this:

$ proj +proj=poly -r cities
# coordinates for a few cities
-4887590.49 7317961.48 Boston, United States
-5542524.55 6982689.05 New York, United States
171224.94 5415352.81 Paris, France
-8101.66 5707500.23 London, England


Am I doing something wrong, or did something change from when the document was written?

Thanks.
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