#2935: r.watershed returns bogus flow direction without warning when using large "virtual" terrain ---------------------+------------------------- Reporter: mankoff | Owner: grass-dev@… Type: defect | Status: new Priority: normal | Milestone: Component: Raster | Version: 6.4.4 Keywords: | CPU: Unspecified Platform: MacOSX | ---------------------+------------------------- I'm using the hydropotential, in units Pa, as my "elevation" for r.watershed in order to route flow under a glacier. The values are larger than a normal elevation, although perhaps not using grass for planetary research. The output of "r.info" follows. When I use this with {{{r.watershed -a --v elevation=phi accumulation=acch drainage=fdir thresh=50 flow=RUh.2k}}}, the {{{fdir}}} results are incorrect.
If I {{{r.mapcalc 'phi = phi / 1000' # [Pa] to [kpa]}}}, then things work. I can provide example files if needed to recreate this. {{{ > r.info phi +----------------------------------------------------------------------------+ | Layer: phi Date: Wed Feb 24 20:37:58 2016 | | Mapset: PERMANENT Login of Creator: mankoff | | Location: Morlighem_2014 | | DataBase: /Users/mankoff/data/grass | | Title: ( phi ) | | Timestamp: none | |----------------------------------------------------------------------------| | | | Type of Map: raster Number of Categories: 255 | | Data Type: DCELL | | Rows: 538 | | Columns: 301 | | Total Cells: 161938 | | Projection: Stereographic | | N: -657600 S: -3349500 Res: 5003.53159851 | | E: 864700 W: -638000 Res: 4992.35880399 | | Range of data: min = -250782 max = 32395007.4 | | | | Data Description: | | generated by r.mapcalc | | | | Comments: | | 1000 * 9.8 * z_b + 917 * 9.8 * (z_s - z_b) | | | +----------------------------------------------------------------------------+ }}} -- Ticket URL: <https://trac.osgeo.org/grass/ticket/2935> GRASS GIS <https://grass.osgeo.org> _______________________________________________ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev