[Proj] lat/long format question

Roger Oberholtzer roger at opq.se
Fri Oct 30 09:59:14 EST 2009

On Fri, 2009-10-30 at 13:13 +0100, OvV_HN wrote:
> ----- Original Message ----- 
> From: "Roger Oberholtzer" <roger at opq.se>
> To: "PROJ.4 and general Projections Discussions" <proj at lists.maptools.org>
> Sent: Friday, October 30, 2009 11:25 AM
> Subject: [Proj] lat/long format question
> > Is there a way to tell proj4 that the lat/long values are, say, degrees
> > and fractions of degrees (dd.dddd), or degrees and minutes and fractions
> > of minutes (ddmm.mmmm)? I don't see this mentioned in the docs. I have
> > no trouble converting them, but in my use, it would be ever so much
> > easier if the conversion was handled in proj. Just curious.
> You could read the fabulous manual:
> Cartographic Projection Procedures for the UNIX Environment—A User’s Manual
> by Gerald I. Evenden, Open-File Report 90–284
> On page 3 are the several forms of input data delineated.
> The manuals as pdfs can be found on the proj website.

Of course I did this. I should have pointed out that I am doing this
from the C API. So, I send floating point numbers to pj_transform().
None of the various markups allowed on text input apply at this point.

I can of course change the representation before calling pj_transform().
And I expect this will be the method I wind up using. But in my code,
and for simplicity and consistency, a low-level solution is best. So, I
am just curious if pj_transform() can be told to expect dd.dddd or
ddmm.mmmm. Perhaps as an option to pj_init_plus() along the line of

I am trying to sort out my options. It would be bad if I re-did
something pj_transform() can already do. So, I am just checking first.

To be honest, I would not think pj_transform() should do this. It would
make most sense if it expected one representation, and left any fiddling
to the caller.

But I had to ask. The list has been too quite :)

Roger Oberholtzer

OPQ Systems / Ramböll RST

Ramböll Sverige AB
Krukmakargatan 21
P.O. Box 17009
SE-104 62 Stockholm, Sweden

Office: Int +46 8-615 60 20
Mobile: Int +46 70-815 1696

More information about the Proj mailing list