[OSRS-PROJ] Prime Meridian Support in PROJ.4

Gerald Evenden gerald.evenden at verizon.net
Thu Oct 3 21:36:53 EDT 2002

Frank Warmerdam wrote:

> Gerald Evenden wrote:
> > Just as an aside from the original author of proj.4:  prime meridian has no place
> > in proj.4.  Any offsets in longitude due to variations in coordinate system "prime
> > meridian" should be taken care of externally with adjustments to "lon_0"
> > parameter.
> Gerald,


> > I know my advice will be ignored but I could not resist expressing my displeasure
> > with the inclusion of PM code within the proj.4 library.  PMS, if you will.

Sorry, but I could not resist "Prime Meridian Syndrome."  :-)

> Well, the corruption started when I introduced support for converting
> between different datums. At that point I was trying to make PROJ.4 into
> a coordinate system conversion library rather than just a projections
> library.  I can see why you feel that is a perversion of the original vision
> of PROJ.4, and the focus of it's role, but that is the danger of open source.
> Your work can be adopted an taken in directions you never intended.
> That said, I think PROJ.4 is serving an important function for lots of other
> projects by taking on the larger role of coordinate systems conversion and
> that integrating that task in one library rather than two layered libraries
> has some benefits.
> Your advice isn't exactly disregarded ... your vision messages cause me lots of
> angst!  It just that user demand (and my own needs) has led me to take PROJ.4
> in a different direction than originally intended.  Obviously we all owe you
> alot as you did all the hard work ... the stuff that I am far from competent
> to do.  But in the end, I will still pursue the features I think are useful
> and needed,

I generally remain silent on changes to proj.4 and try to limit comments to
places where I feel things are going a little too astray.  But in all cases, please
take the comments as friendly suggestions.  I consider the version of proj.4
you and your group is distributing yours and these suggestions are only to remind
you that I'm still looking  over your shoulders.

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