On 21/09/16 09:35, Nikos Alexandris wrote:
Rich Shepard wrote:
The LiDAR source location has x- and y-resolution of 3 feet
(international) and several thousand cells east-west and north-south.
g.region -p for this location displays:
projection: 99 (unnamed)
zone: 0
datum: ** unknown (default: WGS84) **
ellipsoid: grs80
north: 1286590.24500872
south: 1240510.24500872
west: 634966.76150938
east: 664972.76150938
nsres: 3
ewres: 3
rows: 15360
cols: 10002
cells: 153630720
When in the project location g.region -p produces:
projection: 99 (NAD_1983_HARN_StatePlane_Oregon_North_FIPS_3601_Feet_Intl)
zone: 0
datum: nad83harn
ellipsoid: grs80
north: 588219.90693215
south: 536993.58817534
west: 7524575.13218961
east: 7561596.20977101
nsres: 2561.31593784
ewres: 1851.05387907
rows: 20
cols: 20
cells: 400
I want to understand why the nsres is now 2561+ feet, the ewres now
1851+
feet, and the numbers of rows and columns has decreased so drastically.
Looking forward to learning,
Helmut Kudrnovsky:
If it is about raster reprojection, there are hints in the r.proj manual
about region settings before applying r.proj.
E.g.
A simple way to do this is to check the projected bounds of the input map in
the current location's projection using the -p flag. The -g flag reports the
same thing, but in a form which can be directly cut and pasted into a
g.region command.
Some observation: `-g` prints out in shell style, suitable for
`eval`uating. The `eval` utility, for example, constructs a
command, from the given arguments (here, the ouput of `g.region -g`)
which is then executed by the shell. See for example
https://grasswiki.osgeo.org/wiki/Shell_scripting#Using_output_from_GRASS_modules_in_the_script.
A ready to copy-n-paste form is obtained via `-f` (this is a recent
addition by Moritz during the code sprint in Bonn).
Maybe the `-f` flag would be a useful addition to `r.proj` as well.
AFAIR, the -g flag in r.proj already outputs flat format.
Moritz
_______________________________________________
grass-user mailing list
[email protected]
http://lists.osgeo.org/mailman/listinfo/grass-user
