You want the points to represent cell centers so you need to expand your region 1/2 pixel in all four directions. Also look at using r.in.xyz, it works directly on this type of data.
Jamie On Thu, May 13, 2010 at 7:26 AM, Hanlie Pretorius < hanlie.pretor...@gmail.com> wrote: > Hi, > > I've obtained DEMs in text files with columns X, Y and Z at 25m > spacing. The first three entries in the text file are: > > ----- > X,Y,Z > 99550,2.9883e+06,1473.47 > 99550,2.98828e+06,1473.57 > 99550,2.98825e+06,1473.63 > ----- > > To me it seems the easiest way to import these is the following: > > 1. v.in.ascii > > 2. Set the region to the extents of new vector file and the resolution to > 25m. > > 3. v.to.rast. > > > This 'works' but I get horizontal strips of no data in my raster DEM > at 25m spacings. > > Also, when I look at the raster and the vector layer together, the > vector points are not always on the edges of the raster cells. > > Can someone perhaps help me to fix this? > > g.region: > > projection: 99 (Transverse Mercator) > zone: 0 > datum: ** unknown (default: WGS84) ** > ellipsoid: wgs84 > north: 2988300 > south: 2959850 > west: 74300 > east: 99550 > nsres: 25 > ewres: 25 > rows: 1138 > cols: 1010 > cells: 1149380 > > v.info: > > > +----------------------------------------------------------------------------+ > | Layer: dem_2628cc_...@c83 > | Mapset: C83 > | Location: sa_tm_19deg_E > | Database: C:\Hanlie\grassdata > | Title: > | Map scale: 1:1 > | Map format: native > | Name of creator: Administrator > | Organization: > | Source date: Thu May 13 16:06:07 2010 > > > |----------------------------------------------------------------------------| > | Type of Map: vector (level: 2) > | > | Number of points: 1151529 Number of areas: 0 > | Number of lines: 0 Number of islands: 0 > | Number of boundaries: 0 Number of faces: 0 > | Number of centroids: 0 Number of kernels: 0 > | > | Map is 3D: Yes > | Number of dblinks: 0 > | > | Projection: Transverse Mercator > | N: 2988300 S: 2959850 > | E: 99550 W: 74300 > | B: 1429.79 T: 1740.2 > | > | Digitization threshold: 0 > | Comments: > | > > > +----------------------------------------------------------------------------+ > > r.info: > > > +----------------------------------------------------------------------------+ > | Layer: dem_2628cc_...@c83 Date: Thu May 13 16:15:50 2010 > | Mapset: C83 Login of Creator: Administrator > | Location: sa_tm_19deg_E > | DataBase: C:\Hanlie\grassdata > | Title: Categories ( dem_2628cc_25m ) > | Timestamp: none > > > |----------------------------------------------------------------------------| > | > | > | Type of Map: raster Number of Categories: 0 > | Data Type: DCELL > | Rows: 1138 > | Columns: 1010 > | Total Cells: 1149380 > | Projection: Transverse Mercator > | N: 2988300 S: 2959850 Res: 25 > | E: 99550 W: 74300 Res: 25 > | Range of data: min = 1429.850000 max = 1739.410000 > | > | Data Source: > | Vector Map: dem_2628cc_...@c83 in mapset C83 > | Original scale from vector map: 1:1 > | > | Data Description: > | generated by v.to.rast > | > | Comments: > | v.to.rast input="dem_2628cc_...@c83" output="dem_2628cc_25m" > use="z"\ > | type="point,line,area" layer=1 value=1 rows=4096 > | > > > +----------------------------------------------------------------------------+ > > Thanks > Hanlie > _______________________________________________ > grass-user mailing list > grass-user@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/grass-user >
_______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user