On Thu, 10 Jan 2008 22:27:20 -0500
Matt <mlpublic42@gmail.com> wrote:
I am unable to create a new location/project in Grass.
Since I am new to
both Linux/Ubuntu and Grass there are a nearly infinite
ways to go wrong. I
have Ubuntu 7.10 installed. I used Synaptic to install
Grass 6.2.2. I have
been able to start Grass and play with the Spearfish and
North Carolina
datasets. I've made it to page 37 in "Open Source GIS A
Grass GIS Approach,
3rd ed." As interesting as North Carolina is, I yearn to
create a map of
western New York. But when I try to create a new project
closer to home, I
get nowhere. All the tutorials I've come across treat
this as trivial, but
I'm stuck!
Starting Grass from the "Run Application" applet ("run in
terminal" box
checked), starts Grass in the terminal window and a Grass
Startup GUI window
appears. Using the Browse button I enter
"/home/matt/grass/grassdata" in
the GIS Data Directory box. The previous created
directory map1 appears in
the project location box and the Accessible Mapsets
window is empty. At
this point I've tried several things. If before starting
Grass I put a
Tiger shp file (tgr36029lkA.shp) into map1, I'm unable to
use it. If I
click on EPSG codes and select 4326 and click "Define
Location" it tells me
to restart Grass to find the created location. When
restarted the location
is not there.
Any ideas? Especially how to start a new project using a
Tiger shape
file? (Remember, novice).
Thanks,
Matt
Hi Matt!
I am also new in GRASS.
If you have the Book you mention it shouldn't be that hard.
But, (for my own practice as well) I try to describe
step-by-step.
So, try it the "hard" way:
1. Open a Terminal and start grass in text mode:
grass -text
2. Describe the LOCATION ( e.g. CloseToHome), the MAPSET
(e.g. Matt) and the directory in which you want to store
your GIS data base (that is: /wherever/you/store/your/data)
3. AFTER COMPLETING ALL ANSWERS, HIT <ESC><ENTER> TO
CONTINUE
4. Probably you get the message(s):
LOCATION <loseToHome> - doesn't exist
[...]
Would you like to create location <loseToHome> ? (y/n) [y]
Of course you hit the "Enter"
5. Then you get the message(s):
To create a new LOCATION, you will need the following
information:
[...]
Do you have all this information? (y/n) [y]
(a) *** If you don't have them search in the web!
(useful webpage: http://spatialreference.org/)
You can also look after a specific EPSG code and get the
necessary parameters in "proj" format
(b) Once you got the info you continue... (hit "Enter"!)
( Now in your case, since you mentioned EPSG:4326 -
http://spatialreference.org/ref/epsg/4326/proj4/ - which is
actually the WGS84 Datum, you just choose "B", the
Latitude-Longitude coordinate system and verify (again)
your option with "Enter" )
6. Give a description to your project
7. Specify "wgs84" as a geodetic datum
8. type "list" to see available Transformation Parameters
(there is only 1 option) and give "1" when asked).
9. Now you need to DEFINE THE DEFAULT REGION
(geographically of course) so you need the coordinates of
your "Study Area" let's say (Highest & Lowest Latitude &
Longitude values)
and the GRID RESOLUTION (depends on the resolution of the
data with which you want to work -- Notice that in WGS84
you don't define meters but degrees...)
10. You check and accept and hit <ESC><ENTER> and <ENTER>
You should be ready to take off...
** Of course the process of creating a LOCATION is
different depending on the coordinate system you need to
work with.
Try to browse through the GRASS user mailing list and
search for how to import TIGER data. There are already a
couple of answers upon this.