[QGIS-Developer] QGIS 3.8 Transformations dialog

[Nyall Dawson]

On Fri, 28 Jun 2019 at 17:11, Richard Duivenvoorde <rdmailings at duif.net> wrote:
>
> On 28/06/2019 01.28, Nyall Dawson wrote:
> >> That one shows 'just' 2 options (added to the qgis.nl post)
> >> IF the green line is just the first one, but we are not sure if it is
> >> the right one... should we make it green anyway?
>
> > Ah, on proj 6 builds, we ARE sure that the first/green one is the most
> > recommended one :) That's because proj gives us an ordered list of
> > possible operations in order of preference (calculated using all
> > proj's internal smarts and knowledge about the accuracy of different
> > transform operations).
>
> Mmm, then my last question, after this I'll move to proj ;-)
>
> See:
>
> http://www.qgis.nl/media/2019/06/Screenshot-20190627104509-716x467.png
>
> This is QGIS with proj6: As you see there are 2 options. The first one
> being green 'numbered' (3). But the bottom one having a higher number
> between brackets having a (4) between brackets?
>
> Now /me wondering what these numbers are: because given your answer
> above, the green one being 'THE one' :-) I wonder what this other
> numbers are (I was wondering ordered by date/relevance or so)??

These are how proj identifies the coordinate operation -- I'm not
entirely sure what they represent, but I assume they are just indexes.

Nyall