[GRASS-user] newbie user

Levente · May 6, 2012, 6:12pm

Dear Grass fellows,

I am a new member of the list. I installed GRASS on my Debian box, and have no
clue how to continue. Please forgive me my ignorance.

With my father, as a family project, we develop a system, that sends
coordinates to a postgresql database. So far, I have some date in the
database.

My goal would be to SELECT some data from the database, and display it on a
map. Could anyone help me how to achieve this? (no, I don't want google maps).

I am an electrical engineer, and have no clue how does this Geographic stuff
work, so it would be nice to have some pointers in the documentation.

* How can I load a map into GRASS?
* BTW... where can I get a map from?
* How can I (from software) put a point in a map?
* How can I do some analyze stuff like distance from 2 points (on a GUI)
* other stuff will come, like mesh, etc.

Yes, I am prepared to read documents! I'm sorry if all these questions are
stupid, but I think GRASS is what I look for.

Thank you for your help.

--
Levente Kovacs
CTO, CSO
http://levente.logonex.eu

Micha_Silver · May 6, 2012, 6:48pm

Dear Grass fellows,

I am a new member of the list. I installed GRASS on my Debian box, and have no
clue how to continue. Please forgive me my ignorance.

Welcome.

With my father, as a family project, we develop a system, that sends
coordinates to a postgresql database. So far, I have some date in the
database.

My goal would be to SELECT some data from the database, and display it on a
map. Could anyone help me how to achieve this? (no, I don't want google maps).

While I enjoy working with GRASS, in your case it might be “using a 5 kg. hammer to push in a tack”. If you only need to create a point layer from X-Y locations there are several easier to use tools. Did you consider QGIS?
If you find further on that you need the advanced analysis capabilities of GRASS, then QGIS has a GRASS plugin to get you started.

I am an electrical engineer, and have no clue how does this Geographic stuff
work, so it would be nice to have some pointers in the documentation.

* How can I load a map into GRASS?
* BTW... where can I get a map from?
* How can I (from software) put a point in a map?
* How can I do some analyze stuff like distance from 2 points (on a GUI)
* other stuff will come, like mesh, etc.

Yes, I am prepared to read documents! I'm sorry if all these questions are
stupid, but I think GRASS is what I look for.

You’d certainly do well to start with the GRASS documentation:
http://grass.osgeo.org/wiki/GRASS_Help

Daniel_Lee · May 6, 2012, 6:50pm

Hi Levente,

Welcome to the list

The questions you ask could be the subject of a GIS 1 course, especially with GRASS. There are some good tutorials on getting started with GRASS - check out here for example:
http://grass.fbk.eu/intro/firsttime.php

As to where you can get maps from… There are so many sources of geographical data you’d have to specify a little bit more. To be honest, though, if you’re wanting to do the stuff that you describe manually, I would actually be more inclined to point you toward QGIS. QGIS seems to be easier to learn because its GUI is somewhat more… Graphical? Plus, it can connect to PostGIS (Postgres) as well as GRASS, so if you’ve got your data in a GRASS database you can still access it from QGIS. Otherwise GRASS does require a lot of understanding for regional settings, coordinate systems, etc. - all learnable, but as an electrical engineer I would assume it would be quite a bit of reading due to lacking background in that field (which, of course, is understandable).

That said, the tutorial I linked is in pretty good, and GRASS is very awesome, so if you think you’d rather work with it, more power to you. I’m also a big fan.

Hope that helps!
Daniel

–

B.Sc. Daniel Lee
Geschäftsführung für Forschung und Entwicklung
ISIS - International Solar Information Solutions GbR
Vertreten durch: Daniel Lee, Nepomuk Reinhard und Nils Räder

Softwarecenter 3
35037 Marburg
Festnetz: +49 6421 379 6256
Mobil: +49 176 6127 7269
E-Mail: Lee@isi-solutions.org
Web: http://www.isi-solutions.org

2012/5/6 Levente Kovacs <leventelist@gmail.com>

Dear Grass fellows,

I am a new member of the list. I installed GRASS on my Debian box, and have no
clue how to continue. Please forgive me my ignorance.

With my father, as a family project, we develop a system, that sends
coordinates to a postgresql database. So far, I have some date in the
database.

My goal would be to SELECT some data from the database, and display it on a
map. Could anyone help me how to achieve this? (no, I don’t want google maps).

I am an electrical engineer, and have no clue how does this Geographic stuff
work, so it would be nice to have some pointers in the documentation.

How can I load a map into GRASS?

BTW… where can I get a map from?

How can I (from software) put a point in a map?

How can I do some analyze stuff like distance from 2 points (on a GUI)

other stuff will come, like mesh, etc.

Yes, I am prepared to read documents! I’m sorry if all these questions are
stupid, but I think GRASS is what I look for.

Thank you for your help.

–
Levente Kovacs
CTO, CSO
http://levente.logonex.eu

grass-user mailing list
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http://lists.osgeo.org/mailman/listinfo/grass-user

Levente · May 7, 2012, 3:17pm

Thanks for both messages. I think for now I go for QGIS. However, I don’t like the KDE interface. I still don’t know where can I get a map from. I think some basic map would be fine with roads, waters, borders, etc. For start I don’t think I need any 3D information. I give a try to QGIS later this week. Later, I’d like to move to GRASS.

Thanks,
Levente

mlennert · May 7, 2012, 3:52pm

On 07/05/12 17:17, Levente wrote:

Thanks for both messages. I think for now I go for QGIS. However, I
don't like the KDE interface. I still don't know where can I get a map
from. I think some basic map would be fine with roads, waters, borders,
etc.

You can try OpenStreetMap data [1], probably easiest in the form of Cloudmade's [2] or Geofabrik's [3] shapefiles.

Moritz

[1] http://www.openstreetmap.org/
[2] http://downloads.cloudmade.com/
[3] http://download.geofabrik.de/osm/

Micha_Silver · May 7, 2012, 5:18pm

Thanks for both messages. I think for now I go for QGIS. However, I don’t like the KDE interface. I still don’t know where can I get a map from. I think some basic map would be fine with roads, waters, borders, etc. For start I don’t think I need any 3D information. I give a try to QGIS later this week. Later, I’d like to move to GRASS.

The window manager is pretty much irrelevant. QGIS runs under Gnome, XFCE, KDE, Windows, OSX, …
Some of the popular sources of map layers, to get started, include:
Global administrative boundaries: http://www.gadm.org/
Natural Earth data: http://www.naturalearthdata.com/
(and Moritz already mentioned OpenStreetMaps)

···

-- 
Micha Silver
GIS Consultant, Arava Development Co.
[http://www.surfaces.co.il](http://www.surfaces.co.il)

Levente · May 9, 2012, 7:26pm

Ok,

So far, I've downloaded an osm file, and imported to QGIS. It is very slow on
my 2 CPU machine, and it only uses a single CPU at a time. Is there any new
version that supports multi threading? I use 1.4.0.

How can I import a *.osm file into GRASS? Is GRASS faster than QGIS?

I thought it'll be as fast as an on-line map. Why is the so big difference?

Thank you,
Levente

--
Levente Kovacs
CTO, CSO
http://levente.logonex.eu

neteler · May 9, 2012, 8:57pm

On Wed, May 9, 2012 at 9:26 PM, Levente Kovacs <leventelist@gmail.com> wrote:

Ok,

So far, I've downloaded an osm file, and imported to QGIS. It is very slow on
my 2 CPU machine, and it only uses a single CPU at a time. Is there any new
version that supports multi threading? I use 1.4.0.

Very unlikely. To make either QGIS or GRASS multi-core ready in a significant
way (e.g. with openMP), it is a long way to go.

How can I import a *.osm file into GRASS? Is GRASS faster than QGIS?

By chance this week a new library came out:
https://www.gaia-gis.it/fossil/readosm/home
"ReadOSM is an open source library to extract valid data from
within an Open Street Map input file."

I thought it'll be as fast as an on-line map. Why is the so big difference?

Online map portals never show the true underlying data but some aggregated
material. Hence much faster than when working in a GIS with the true data.

Markus

Hamish · May 10, 2012, 3:29am

Levente wrote:

> How can I import a *.osm file into GRASS?

...
MarkusN:

By chance this week a new library came out:
https://www.gaia-gis.it/fossil/readosm/home
"ReadOSM is an open source library to extract valid data
from within an Open Street Map input file."

see also v.in.osm and v.in.osm2 scripts from wiki addons, and an older
osm2grass.sh script there.

http://grass.osgeo.org/wiki/GRASS_AddOns#v.in.osm

Typically you'd use the java xapi interface to just download the region
and/or map features you were interested in. Depending on what you are
doing, the JOSM downloader -> Save As ... is another route.

http://openstreetmap.us/uixapi/xapi.html
http://wiki.openstreetmap.org/wiki/Xapi
http://wiki.openstreetmap.org/wiki/Josm

.osm is just an XML text file so simple to work with, gpsbabel is used as
the intermediate conversion tool for v.in.osm2. Biggest trouble perhaps
is that the tagging rules are by design rather informal & open-ended.
Things like the number of nodes per feature are more strict as a byproduct
of memory/coding limitations at the time the latest API was developed, so
a reasonable GIS should have no problem with the internals of the dataset,
just perhaps the expanse of it.

Hamish