[OSRS-PROJ] proj binary coordinates: radians or degrees?
Gerald I. Evenden
gevenden at capecod.net
Tue Jul 4 19:44:30 EDT 2000
The last few entries to OSRS-PROJ have produced disturbing suggestions
for changes to 'proj' that I would like to comment on. This is the first.
The purpose of the binary I/O capability of proj was to facilitate data
of "like-minded" programs. For example, to simply transform cartesian
coordinates from one projection to another the process would be facilitated
proj [projection source parms] -I -o | proj [projection destination
By doing this, we avoid extra computations of formating/deformating and
the probable loss of precision.
The the binary could be in decimal degrees, but why bother. Most
software I have used/written work with angular information in radians and it
is the natural state of all angular arguments to transcendental functions.
Arcane degrees are an artifact of the unwashed external world and not
used in internal computations.
Because we cannot read binary (well maybe a few gifted can) why would
we care if the data is in degrees when the natural internal is in radians?
This information is for program to program communications so lets keep
it in their language.
Jerry Evenden and the Low Riders, Katie and Daisy May
gevenden at capecod.net http://www.capecod.net/~gevenden
----- Original Message -----
From: Frank Warmerdam <warmerda at home.com>
To: <osrs-proj at remotesensing.org>
Sent: Tuesday, July 04, 2000 11:54 AM
Subject: [OSRS-PROJ] proj binary coordinates: radians or degrees?
> Thomas Knudsen had kindly provided patches for proj to handle binary IO
> properly on windows and DOS. He has also run into the fact that proj
> coordinate io is in radians, instead of degrees. Before changing the
> of binary file io to degrees, like formatted results, I wanted to query
> list, and see if anyone anticipates this causing significant hardship.
> So, is it OK with everyone if I change the proj commands binary lat/long
> coordinates to be in degrees instead of radians?
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