[GRASS-dev] Re: r.external

[Markus Neteler]

On Sun, Sep 14, 2008 at 1:06 AM, Glynn Clements
<glynn at gclements.plus.com> wrote:
> Markus Neteler wrote:
>
>> So the range (slightly incorrect) survives, but G_write_fp_range()
>> isn't writing it out.
>
> Okay; I think that r33435 should fix it:
>
> --- raster/r.external/main.c    (revision 33434)
> +++ raster/r.external/main.c    (working copy)
> @@ -454,12 +454,14 @@
>        struct Range range;
>        range.min = (CELL)info->range[0];
>        range.max = (CELL)info->range[1];
> +       range.first_time = 0;
>        G_write_range(output, &range);
>     }
>     else {
>        struct FPRange fprange;
>        fprange.min = info->range[0];
>        fprange.max = info->range[1];
> +       fprange.first_time = 0;
>        G_write_fp_range(output, &fprange);
>        write_fp_format(output, info);
>        write_fp_quant(output);

Yes, it solved the problem. Backported to 6.4.svn.

> I'm assuming that the inaccuracy in the range is due to the lack of
> the -r flag. Without that flag, GDAL calculates an approximate range
> from a sampling of cells, rather than processing the entire map.

Using the -r flag helps certainly, too:
r.info -r pat_dtm_5m
WARNING: category support for [pat_dtm_5m] in mapset [PERMANENT] missing
min=0.000000
max=3758.871094

Thanks again for this great module and assistance (so I can avoid to
by another terabyte for my imported (now linked) provincial geodata.

Markus