Hi Jamie, Thanks, this worked perfectly.
Regards Hanlie 2010/5/13, Jamie Adams <jaad...@gmail.com>: > Did you adjust the region also? To do this properly, you need to first scan > the file using r.in.xyz to get the extents. I'd also use the shell style > output. > > r.in.xyz -sg input="2628cc.ORT.xyz" output="dem_2628cc_25m_xyz > > Should return something like: > > n=1000 s=500 w=500 e=1000 t=### b=### > (you can ignore the t & b output) > > This is the extent of the points, which are going to be the center of the > output pixels. Since the region is defined as pixel edge, you need to > expand the region 1/2 a pixel in each direction to ensure the points are in > the center of the pixel. At 25m spacing, your region should be set as: > > g.region n=1012.5 s=487.5 w=487.5 e=1012.5 res=25 > > - Jamie > > On Thu, May 13, 2010 at 9:02 AM, Hanlie Pretorius < > hanlie.pretor...@gmail.com> wrote: > >> Hi Jamie, >> >> I tried r.in.xyz: >> (r.in.xyz input="2628cc.ORT.xyz" output="dem_2628cc_25m_xyz" >> method="mean" type="FCELL" x=1 y=2 z=3 zscale=1.0 percent=100) >> >> but I still get the rows of no data in the result. >> >> Hanlie >> >> >> > >> > 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 >> >> >> > -------------- next part -------------- >> > An HTML attachment was scrubbed... >> > URL: >> > >> http://lists.osgeo.org/pipermail/grass-user/attachments/20100513/dd33d293/attachment.html >> > >> > ------------------------------ >> > >> > _______________________________________________ >> > grass-user mailing list >> > grass-user@lists.osgeo.org >> > http://lists.osgeo.org/mailman/listinfo/grass-user >> > >> > >> > End of grass-user Digest, Vol 49, Issue 24 >> > ****************************************** >> > >> > _______________________________________________ grass-user mailing list grass-user@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-user