[GRASS-user] data format changing

[Markus Neteler]

On Mon, Sep 17, 2012 at 7:14 AM, 巩哲 <gongzhe79 at gmail.com> wrote:
>
>     Hi,I had met some problems about data format.
>     Firstly,I imported SPOTVGT NDVI file into GRASS, by using i.in.spotvgt,
> the data range is -0.96~0.92 (already resampled by r.mapcalc).

Yes, this is within the NDVI range.

> Then I need a binary image

What do you mean with "binary map"? Which format would you like to use?

> for analyzing in another software,so I exported
> the map by using r.out.bin -ib input=XXXXX,output=XXXXX,then a 16 bit binary
> image was created, but the data value became only 0 or 1.

You requested an integer map
http://grass.osgeo.org/grass64/manuals/html64_user/r.out.bin.html

so values in the range of -1 ... +1 are mapped into -1,0,1.

> So when and where
> should I change the data format by using what command?

To share data with other software packages, likely r.out.gdal is the better
option to export to common GIS formats.

Markus