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.pretorius@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: 1149380v.info:
+----------------------------------------------------------------------------+
| Layer: dem_2628cc_25m@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_25m@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_25m@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_25m@C83" output="dem_2628cc_25m"
use="z"\
| type="point,line,area" layer=1 value=1 rows=4096
|+----------------------------------------------------------------------------+
Thanks
Hanlie
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