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 [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
