[GRASS-user] Fixing the error: G_set_window(): Illegal latitude for North

[Glynn Clements]

Hamish wrote:

> > The error mostly occurs when importing non-georeferenced images into a
> > lat/lon location.
> > 
> > Non-georeferenced images are normally imported with the lower-left
> > corner at (0,0) and with a resolution of one unit per cell. For a
> > lat/lon location, this typically results in the top edge of the image
> > being above 90 degrees, hence the error.
> ..
> > It can sometimes occur when importing geo-referenced images where the
> > top row is centred on 90N, resulting in the top edge being half a cell
> > above that. I am not aware of any workaround for this case.
> 
> The last case is a bit of an anomaly as every cell in the row must contain the
> same value, as they overlap at the pole. If they are not all the same, you
> could claim that the dataset was broken.... the next pragmatic question is how
> to accomodate broken datasets without annoying users too much? Throw away the
> row at the pole? (ie instead of G_fatal_error() import as much as possible with
> a warning that some data has been thrown away- please check & here's probably
> why it happened.

That's the most straightforward solution, but it needs to be done in
the importer (r.in.*) rather than libgis.

The only viable libgis fix is to simply remove the latitude check.

> I guess that is still problematic for longitude when column
> >360 wants to wrap around and overwrite earlier <360 data ?)

I suppose the same issue could apply here.

-- 
Glynn Clements <glynn at gclements.plus.com>