[Qgis-developer] Module piping GUI [Was: analytical workflow]

[Martin Dobias]

On Thu, Sep 29, 2011 at 4:01 PM, Jürgen E. <jef at norbit.de> wrote:
> Hi,
>
> On Thu, 29. Sep 2011 at 15:35:18 +0200, Andreas Neumann wrote:
>> yes - you are right. FME is a ETL tool (like GeoKettle, Java based). I
>> still think it can be a source of inspiration. ETL may be something
>> different but it has a LOT in common with what you probably want to
>> achieve in a model builder for analytical workflows.
>
> Isn't this ultimatly just processing input to output - and deciding whether the
> process is "analysis" or "transformation" is just a matter of one's point of
> view?

Yes generally it is the same thing, but I guess they work at a
different conceptual level.

>From my point of view an analytical tool is typically a module that
expects one or more input layers, some parameters and returns one or
more output layers. The ETL tools typically work on a different level
of abstraction - parsing files, aggregating fields, joining fields of
other tables and maybe producing output in a different syntax...

Comparing GUIs for spatial analyses (esri model builder, sextante
etc.) and ETL (FME, GeoKettle) they show many similarities. ETL
software generally models more complex dependencies and the workflows
seem more like visual programming than just simple concatenation of
processing modules as with analyses.

Regards
Martin