[Proj] how to compare 2 proj4 definitions? or: how to normalize proj4 definition?

[Frank Warmerdam]

Gerald I. Evenden wrote:
> On Wednesday 28 February 2007 12:50 pm, Frank Warmerdam wrote:
>> Sergey Spiridonov wrote:
>>> -----BEGIN PGP SIGNED MESSAGE-----
>>> Hash: SHA1
>>>
>>> Hi
>>>
>>> I need to compare two proj4 definitions. It is clear that I can not
>>> compare them as strings, because order of the parameters can be changed,
>>> floats can be in different format, there can be various units.
>>>
>>> Is there any normalization function available. If not, I will write one.
>> Sergey,
> 
> I was totally confused by the above request and thus chose to ignore it.  But 
> I was confused even more by the response so please forgive my added notes.

Gerald,

I believe Sergey is looking for a way of comparing PROJ.4 projection
definitions to see if they are equivelent.  By normalization he means
putting the coordinate system definition into a "normalized form" such
that two equivelent coordinate system definitions will have the same
string representation.  I'm not sure if this is a proper use of the word
normalize, but it was at least clear to me.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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