Re: r.slope.aspect with -n flag giving aspect of flat areas as -9998
Anna Petrášová <[email protected]>
| Newsgroups | gmane.comp.gis.grass.devel |
|---|---|
| Message-ID | <CAE0EDEo-H7RmPpx78oOjCXv_EKAU1LsNHZYEXO2zbh1w22tWyw@mail.gmail.com> |
Yes, please create an issue on github: https://github.com/OSGeo/grass/issues/new/choose On Tue, Jan 28, 2020 at 6:49 AM Pedro Venâncio <[email protected]> wrote: > Hi all, > > I was testing r.slope.aspect with the "new" -n flag, also to include -e > and -n flags in QGIS Processing, but -n flag is giving aspect values of > flat areas as -9998, instead of -9999, when the precision choosed is CELL, > and the output data type is CELL. > > https://grass.osgeo.org/grass78/manuals/r.slope.aspect.html > > I've tested with GRASS 7.6 (on Linux) and GRASS 7.8.2 (on Windows), both > in the GUI and CLI. > > (Tue Jan 28 11:19:40 2020) > > r.slope.aspect -e -n --verbose elevation=SRTM_PT_25m@PERMANENT > slope=SRTM_PT_25m_Slope_Deg_GRASS aspect=SRTM_PT_25m_Aspect_Std_GRASS > precision=CELL > Percent complete... > Elevation products for mapset <PERMANENT> in <SRTM_PT_25m> > Min computed aspect 0.0000, max computed aspect 360.0000 > Aspect raster map <SRTM_PT_25m_Aspect_Std_GRASS> complete > Min computed slope 0.0000, max computed slope 75.2970 > Slope raster map <SRTM_PT_25m_Slope_Deg_GRASS> complete > (Tue Jan 28 11:20:24 2020) Comando terminado (43 sec) > > r.info map=SRTM_PT_25m_Aspect_Std_GRASS@PERMANENT > > > +----------------------------------------------------------------------------+ > | Map: SRTM_PT_25m_Aspect_Std_GRASS@ Date: Tue Jan 28 11:20:24 > 2020 | > | Mapset: PERMANENT Login of Creator: > PedroVenancio | > | Location: SRTM_PT_25m > | > | DataBase: D:\ICNF\Modelos_Combustivel_2018\Landscape_File\grass78 > | > | Title: Aspect counterclockwise in degrees from east > | > | Timestamp: none > | > > |----------------------------------------------------------------------------| > | > | > | Type of Map: raster Number of Categories: 360 > | > | Data Type: CELL > | > | Rows: 23200 > | > | Columns: 11360 > | > | Total Cells: 263552000 > | > | Projection: ETRS89 / Portugal TM06 > | > | N: 278000 S: -302000 Res: 25 > | > | E: 164000 W: -120000 Res: 25 > | > | Range of data: min = -9998 max = 360 > | > | > | > | Data Source: > | > | raster elevation file SRTM_PT_25m@PERMANENT > | > | > | > | > | > | Data Description: > | > | generated by r.slope.aspect > | > | > | > | Comments: > | > | aspect map elev = SRTM_PT_25m@PERMANENT > | > | zfactor = 1.00 > | > | min_slope = 0.000000 > | > | > | > | r.slope.aspect --verbose -e -n elevation="SRTM_PT_25m@PERMANENT" > slo\ | > | pe="SRTM_PT_25m_Slope_Deg_GRASS" > aspect="SRTM_PT_25m_Aspect_Std_GRAS\ | > | S" format="degrees" precision="CELL" zscale=1.0 min_slope=0.0 > | > | > | > > +----------------------------------------------------------------------------+ > (Tue Jan 28 11:26:09 2020) Comando terminado (0 sec) > > > > Using the default precision as FCELL, all goes ok: > > (Tue Jan 28 11:33:08 2020) > > r.slope.aspect -e -n --verbose elevation=SRTM_PT_25m@PERMANENT > slope=SRTM_PT_25m_Slope_Deg_GRASS_2 aspect=SRTM_PT_25m_Aspect_Std_GRASS_2 > Percent complete... > Elevation products for mapset <PERMANENT> in <SRTM_PT_25m> > Min computed aspect 0.0000, max computed aspect 359.8096 > Aspect raster map <SRTM_PT_25m_Aspect_Std_GRASS_2> complete > Min computed slope 0.0000, max computed slope 75.2970 > Slope raster map <SRTM_PT_25m_Slope_Deg_GRASS_2> complete > (Tue Jan 28 11:34:01 2020) Comando terminado (53 sec) > > (Tue Jan 28 11:34:27 2020) > > r.info map=SRTM_PT_25m_Aspect_Std_GRASS_2@PERMANENT > > > +----------------------------------------------------------------------------+ > | Map: SRTM_PT_25m_Aspect_Std_GRASS_ Date: Tue Jan 28 11:34:01 2020 > | > | Mapset: PERMANENT Login of Creator: > PedroVenancio | > | Location: SRTM_PT_25m > | > | DataBase: D:\ICNF\Modelos_Combustivel_2018\Landscape_File\grass78 > | > | Title: Aspect counterclockwise in degrees from east > | > | Timestamp: none > | > > |----------------------------------------------------------------------------| > | > | > | Type of Map: raster Number of Categories: 360 > | > | Data Type: FCELL > | > | Rows: 23200 > | > | Columns: 11360 > | > | Total Cells: 263552000 > | > | Projection: ETRS89 / Portugal TM06 > | > | N: 278000 S: -302000 Res: 25 > | > | E: 164000 W: -120000 Res: 25 > | > | Range of data: min = -9999 max = 359.8097 > | > | > | > | Data Source: > | > | raster elevation file SRTM_PT_25m@PERMANENT > | > | > | > | > | > | Data Description: > | > | generated by r.slope.aspect > | > | > | > | Comments: > | > | aspect map elev = SRTM_PT_25m@PERMANENT > | > | zfactor = 1.00 > | > | min_slope = 0.000000 > | > | > | > | r.slope.aspect --verbose -e -n elevation="SRTM_PT_25m@PERMANENT" > slo\ | > | pe="SRTM_PT_25m_Slope_Deg_GRASS_2" > aspect="SRTM_PT_25m_Aspect_Std_GR\ | > | ASS_2" format="degrees" precision="FCELL" zscale=1.0 min_slope=0.0 > | > | > | > > +----------------------------------------------------------------------------+ > (Tue Jan 28 11:34:28 2020) Comando terminado (0 sec) > > > The elevation map I'm using is this one: > https://www.fc.up.pt/pessoas/jagoncal/srtm/SRTM_PT_25m.tif > > As CELL is a 32 bit integer with a range from -2,147,483,647 to > +2,147,483,647, -9999 should be fine to conform inside it. > > Another issue I see is in r.info, that is showing the title as > > | Title: Aspect counterclockwise in degrees from east > > which is not correct in this case, as the -n flag was used. > > Could these be bugs? > > Thank you very much. > > Best regards, > Pedro Venâncio > _______________________________________________ > grass-dev mailing list > [email protected] > https://lists.osgeo.org/mailman/listinfo/grass-dev _______________________________________________ grass-dev mailing list [email protected] https://lists.osgeo.org/mailman/listinfo/grass-dev