[gdal-dev] Pre-RFC for OGRSpatialReference use in GDAL and changes in how to deal with axis order issues

[Even Rouault]

On mercredi 19 décembre 2018 11:29:09 CET Andrew C Aitchison wrote:
> On Wed, 19 Dec 2018, Even Rouault wrote:
> > On mercredi 19 décembre 2018 06:30:30 CET Andrew C Aitchison wrote:
> >> Do we need to consider (real and false) precision when converting between
> >> OGRSpatialReference and string ?
> 
> My concern is that since since a WKT1 string encodes floating point
> values as strings and an OGRSpatialReference stores them as doubles,
> a round trip (eg saving to file and reading back, or vice versa)
> will sometimes not preserve the last digit(s).
> 
> My reference to "false precision" was something like 1.1 becoming
> eg. 1.1000000000001
> 
> Looking in more detail at your proposal, I guess this wont bring up
> anything new, since we are using the existing routines
> OGRSpatialReference::importFromWkt() and GetSpatialRef()->ExportToWkt1()
> where this issue will have already been considered.

Indeed, nothing new on this. Except that the import/export from/to WKT will be 
done by PROJ 6 now. It uses %.15g formatting

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