jamaas wrote > I'm a beginner with GRASS, running newest version 7.0.2 on Ubuntu Linux > 14.04. > > I'm attempting to create a new smaller region, and change the resolution > to something slightly larger. For some reason the map I get in the GUI > display window is very detailed however when I try to set a new region > using g.region it tells me that there is no detail to do it. > > Apologies for all of the detail. > > - This is working with raster maps from the UK ordinance survey (OS) > system > - Originally downloaded four individual raster maps from OS is a sort of > .asc format > - Then converted them to ARCGIS format using ARCGIS > - Then combined them into one raster using mosiac to raster, then > converted back to .asc > - I've now imported the .asc raster into GRASS and it looks fine, lots of > detail but I want try to do some hydrologic modelling using TOPMODEL so > need to produce and topidx file, but before that I want to get a smaller > region > -when I attempt to get a smaller region using g.region I get an invalid > input error. > -when I look at the raster info using g.region -p, there is almost no > information > ========================== > (Mon Dec 14 11:36:09 2015) > > g.region -p > > projection: 99 (Transverse Mercator) > zone: 0 > datum: osgb36 > ellipsoid: airy > north: 1 > south: 0 > west: 0 > east: 1 > nsres: 1 > ewres: 1 > rows: 1 > cols: 1 > cells: 1 > (Mon Dec 14 11:36:09 2015) Command finished (0 sec) > =============================== > Something doesn't add up, the information must be in the raster because I > can see it, any suggestions as to what I've done wrong or how to extract > the correct region using UK british national grid references? > > Thanks for any suggestions pointing me in the right direction.
adjust the region to your raster, e.g. g.region -a raster=elevation@PERMANENT align=elevation@PERMANENT g.repion -p to show the region settings then digitize a vector polygon for the region of your intereset, then do g.region -a raster=elevation@PERMANENT vector=yourvector align=elevation@PERMANENT to shrink your region to the area of your interest g.repion -p to show the region settings HTH ----- best regards Helmut -- View this message in context: http://osgeo-org.1560.x6.nabble.com/attempt-to-define-a-smaller-region-tp5241216p5241220.html Sent from the Grass - Users mailing list archive at Nabble.com. _______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
