Agus,
raster tracks the min and max values but does not track the mean and std;
and most file formats cannot store them. The zeros are 'default' values;
would it help to set them to another value that QGIS recognizes; perhaps to
the NA value? I could add an option to compute and add the mean and std
values.
Robert

On Fri, Aug 10, 2012 at 1:25 AM, Agustin Lobo <alobolistas@gmail.com> wrote:

> I've just noted that files created with writeRaster() have wrong stats
> (which is a problem later in Qgis, for example).
> Not sure if writeRaster() uses rgdal, in that case the problem might
> be more general:
>
> > delme <- subset(adlstest,c("B48","B31","B21"))
> > summary(delme)
> Cells:  1089
> NAs  :  0 0 0
>
>            1    2    3
> Min.    2563 3491 3822
> 1st Qu. 2700 3636 3971
> Median  2764 3691 4009
> Mean    2781 3699 4014
> 3rd Qu. 2862 3765 4055
> Max.    3629 3979 4258
>
> > GDALinfo("delme.tif")
> rows        33
> columns     33
> bands       3
> origin.x        648490.8
> origin.y        7058623
> res.x       29.9746
> res.y       29.99077
> ysign       -1
> oblique.x   0
> oblique.y   0
> driver      GTiff
> projection  +proj=utm +zone=19 +south +datum=WGS84 +units=m +no_defs
> file        delme.tif
> apparent band summary:
>    GDType Bmin Bmax Bmean Bsd hasNoDataValue NoDataValue
> 1 Float32 2563 3629     0   0           TRUE           0
> 2 Float32 3491 3979     0   0           TRUE           0
> 3 Float32 3822 4258     0   0           TRUE           0
> Metadata:
> AREA_OR_POINT=Area
>
> Note the 0 means and sd !
>
> adlstest here:
> http://dl.dropbox.com/u/3180464/adlstest.rda
>
> Agus
>
> > sessionInfo()
> R version 2.15.1 (2012-06-22)
> Platform: x86_64-pc-linux-gnu (64-bit)
>
> locale:
>  [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C
> LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8
> LC_MONETARY=en_US.UTF-8
>  [6] LC_MESSAGES=en_US.UTF-8    LC_PAPER=C                 LC_NAME=C
>                LC_ADDRESS=C               LC_TELEPHONE=C
> [11] LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C
>
> attached base packages:
> [1] stats     graphics  grDevices utils     datasets  methods   base
>
> other attached packages:
> [1] rgdal_0.7-5   raster_2.0-08 sp_0.9-99
>
> loaded via a namespace (and not attached):
> [1] grid_2.15.1     lattice_0.19-30 tools_2.15.1
>
> _______________________________________________
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> R-sig-Geo@r-project.org
> https://stat.ethz.ch/mailman/listinfo/r-sig-geo
>

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