Part I - g.region
1)Let`s set geographic region with g.region in command line and Run (GUI).
2)Choose maps which will define working region and only. Don`t choose anything else right now.
Part II - r.patch
1)Launch r.patch in command line, run with GUI it.
2)Choose raster maps (input)
3)Give name for resultant raster map (output)
Now you`ve got a new map in raster map list
File->Import Raster Map->Multiple Formats Using Gdal
and woila - here it is - r.in.gdal (or v.in.gdal, if importing vectors).
Otherwise (faster, by the way) importing raster using command line the same command - r.in.gdal and run in GUI.
If the raster (or vector) data has no specified coordinate system, you can
1) set it using ogr2ogr or
2) ignore this fact, and check Override projection (use location`s projection) under the Options tab.
In Latvia we have historical problems with coordinate systems. Some times we need to work in one of them, some times in other.
This ir how to set coordinate systems from one to another
I have shp file in LKS coordinates. I need to make false north 60000000.
1)Let`s set the coordinate system in file we`re working to.
ogr2ogr -a_srs EPSG:3059 /media/kratuve/gis_latvija/ARC_hydro/auce/lauks_LKS.shp /media/kratuve/gis_latvija/ARC_hydro/auce/lauks.shp
2)Let`s transfer coordinate system to WGS CoordSys.
ogr2ogr -t_srs EPSG:2100 /media/kratuve/gis_latvija/ARC_hydro/auce/lauks_WGS.shp /media/kratuve/gis_latvija/ARC_hydro/auce/lauks_LKS.shp
For raster data we can use gdalwarp instead of ogr2ogr
Interesting artefacts about ogr2ogr and gdalwarp.
Using previous example with vector data (ogr2ogr), the data transformed correctly. But when I used the same parameters in gdalwarp, the data were transformed to the north, but they were incorrectly transformed. I tried hardcoded transformation.
1)First by setting known coordinate system for file
gdalwarp -s_srs "+proj=tmerc +lat_0=0 +lon_0=24 +k=0.99960
0 +x_0=500000 +y_0=-6000000 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs" /media/kratuve/gis_latvija/ARC_hydro/auce/"$inputFileName".tif /media/kratuve/gis_latvija/ARC_hydro/auce/"$outputFileName"_CH.tif
2)Second transform the coordinate system by adding (or in this case subtracting, because in previous step false northing [y0] is -6M) 60000000
gdalwarp -t_srs "+proj=tmerc +lat_0=0 +lon_0=24 +k=0.99960
0 +x_0=500000 +y_0=0 +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +units=m +no_defs" /media/kratuve/gis_latvija/ARC_hydro/auce/"$outputFileName"_CH.tif /media/kratuve/gis_latvija/ARC_hydro/auce/"$outputFileName"_TR.tif
and it worked fine for me.
Additional info - bash script sample
Reinstalled Ubuntu three times
Problems with fTools, as I mentioned before, on Ubuntu Karmic with QGIS 1.4.0 were "solved" (as I`m not very trustworthy to freeware)
Firstly I followed these instructions, installing and compiling ECW, MrSID, GDAL and GRASS seperately from QGIS, but still while making fTools "Dissolve", QGIS crashed.
Launching QGIS, on terminal I got an error
*** glibc detected *** qgis: double free or corruption (fasttop): 0x00007ff38002b9a0 ***
and I found out, that this glibc error is solved by typing
Unnecessary problems are not wanted.
I found out that problems might be in python and SIP bindings. So it seems, that i should upgrade SIP and PyQt4 and then recompyle QGIS from source...
that`s sux. truly sux.
and after that restarting network modules usingsudo apt-get install network-manager-pptp /
sudo /etc/init.d/networking restart
I`m wondering, why these packages aren`t included in Karmic by default?
package qgis is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source. E: Package qgi has no installation cadidate.Messing around in google i found the way, how to correctly install qgis on Karmic.
Copied from ubuntugeek.com
First you need to open the terminal and run the following command
sudo add-apt-repository ppa:ubuntugis/ubuntugis-unstable/
Update the source list
sudo apt-get update
Install qgis using the following command
sudo apt-get install qgis
Following the perrygeo.net instructions I tried to install other software, like GRASS and its plugins, mapserver-bin, gdal-bin, python-qt4, python-sip4, but I got message in terminal that these packages are already installed (assuming they`re installed together with QGIS).
Of course. perrygeo.net article is written 3 years ago... no more wonderings.
But still i was able to install python-gdal, cgi-mapserver, python-mapscript, gmt (which includes gmt-coastline-data), r-recommended, gpsbabel,
But still (x2), I bet, it is very good place where to start. For true newbies, like me.
Groundwater. Freeware. Modelling. Nice pictures.
These are keywords or my work. I started with all of them together reading materials and finding out what kinda free software I can use.
The OS and software I`m on right now -
OS = Linux Ubuntu 9.10 (Karmic Koala).
Software. I`ll focus mainly on QuantumGIS, GRASS and R, following discussions with collegues in Uni. But for each of them there will be a seperate story and discussions.
Here we go.