>> Checking the range of the raster I used for a mask in my >> r.mask command, it was 0-32767; so shouldn't r.mask in=MAP also create a >> mask >> where any non-null cell in the input raster exists? >> >> Here's the output from r.info for the mask I created using r.mask:
>MASK maps usually look like this. It would be more useful to see the >r.info output for the original map. r.info output for original map from which the mask was created: $ r.info Diff_Nov2007_Oct2007_1m +----------------------------------------------------------------------------+ | Layer: Diff_Nov2007_Oct2007_1m Date: Mon Feb 4 14:10:04 2008 | | Mapset: PERMANENT Login of Creator: epatton | | Location: Charlottetown | | DataBase: /home/epatton/Projects | | Title: ( Diff_Nov2007_Oct2007_1m ) | | Timestamp: none | |----------------------------------------------------------------------------| | | | Type of Map: raster Number of Categories: 255 | | Data Type: FCELL | | Rows: 1136 | | Columns: 1249 | | Total Cells: 1418864 | | Projection: UTM (zone 20) | | N: 5119638 S: 5118502 Res: 1 | | E: 491292 W: 490043 Res: 1 | | Range of data: min = -2.809999 max = 1.246000 | | | | Data Description: | | generated by r.mapcalc | | | | Comments: | | EC_Charlottetown_Bathy_November_2007_1m_fill - | | EC_Charlottetown_Bathy_October_2007_1m | | | +----------------------------------------------------------------------------+ >I'm assuming that the original does contain nulls (otherwise the >r.mapcalc method wouldn't do anything either). Is the original map a >reclass map? Yes, the original contains nulls. The original map is not a reclass, but the cell values do cross through zero, if that matters. >The r.mapcalc method creates a completely new map, while r.mask >creates a reclass map. A reclass map takes much less space, but is >affected by any changes to the underlying map (which can be good or >bad, depending upon what you want), and may be susceptible to a >different set of bugs, quirks and corner cases than a normal >(non-reclass) map. Good to know; I'll use the r.mapcalc method as it seems a bit more immune to strangeness. I'll add some hints about this in the r.mask docs, too. ~ Eric. _______________________________________________ grass-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-dev
