[GRASSLIST:3335] help


Hello.

I am new to GRASS, GIS and UNIX . . . . as you would expect i’m having learning curve issues. I’m trying to use grass for my dissertation that entails very basic things like plotting several different types of archaeological materials as well as a bit more advanced issues such as plotting and processing geophysical data (collected with a magnetometer and conductivity meter). I have read Neteler and Mitasova’s book on GRASS and consulted several online tutorials and faq’s. Does any one happen to know of a tutorial or faq specifically targeted for archaeologists or perhaps know of a general introduction course on GRASS?

Thank you much,

Chet Walker


Chet Walker312.857.7629
Research Assistant
Department of African and Amerindian Art
The Art Institute of Chicago

Not off hand, but I am in the same exact situation as you...with the exception of the dissertation part. I am new to GRASS and Linux and I am an archaeologist working on setting up a coherent and functioning system. I'm am anxious to see if anyone has a good answer to you question.

Steve

Chet Walker wrote:

Hello.

I am new to GRASS, GIS and UNIX . . . . as you would expect i'm having learning curve issues. I'm trying to use grass for my dissertation that entails very basic things like plotting several different types of archaeological materials as well as a bit more advanced issues such as plotting and processing geophysical data (collected with a magnetometer and conductivity meter). I have read Neteler and Mitasova's book on GRASS and consulted several online tutorials and faq's. Does any one happen to know of a tutorial or faq specifically targeted for archaeologists or perhaps know of a general introduction course on GRASS?

Thank you much,
Chet Walker

________________________________________
Chet Walker 312.857.7629
Research Assistant
Department of African and Amerindian Art
The Art Institute of Chicago

--

Hallo Chet,

I am an archaeologist and have been working with GRASS for about 6 or 7 years now.
To flatten your learning curve, I will give a (very) short summary of what
I think GRASS GIS is good for in archaeology:

- GRASS has a lot of analytical functionality for raster maps (integer, i.e.
  categorised data and floating points, i.e. metric measurements)
- you can easily create knew functionality by combining the inputs and outputs
  of modules using shell scripts. If you know C, there is no limit to what you
  can do
- GRASS up to version 5.3 is very limited when it comes to advanced vector
  capabilities. This is changing for the better as work on 5.7 progresses
- GRASS has very limited CAD functionality. It's not a good choice for editing
  your own vector maps
- GRASS is great for pulling in data from all sorts of different sources, rasterising
  it, running your analyses and outputing it to another format for publication

Now, where would your sort of work fit into this?
Plotting and processing geophysical data is possible
through GRASS' excellent support of floating point raster maps.
You can easily:
- import measurements in regular grids from ASCII-data (r.in.ascii, or s.in.ascii, then
  pass it on to e.g. s.surf.rst to create an interpolated raster)
- build nice colortables to make measurements more easily interpretable
  (easiest way of doing this is by editing color tables directly. See GRASS5 programming manual)
- patch different grids together (r.patch)
- use neighbourhood functions to smooth out data
  (r.neighbors although I am not aware of a dedicated low or high pass filter)
- use map-algebra to implement any other sort of filters
  (r.mapcalc -- if you know the math -- I certainly don't)
- interpolate missing data points (e.g. r.surf.idw)
- handle NULL data values
- drap data over a digital terrain model (nviz)
- export to tons of raster formats (r.out.*)

... plotting several types of archaeological material
Well, what sort of plots are you thinking about?
I assume you are planning to do plots of site/artefact distributions over some
sort of map data. It's easy to get the coordinates of your things
into GRASS by using s.in.ascii. You can then do very basic plots using s.display.
Look into ps.map manual pages to find out how to do more visually
pleasing stuff.
But really, if you are planning to do statistical plots,
use the GRASS-R interface to pull your data into the R statistical
programming environment (www.r-proj.org) and you have a system that
covers EVERY imaginable aspect of plotting/statistics.

I have never come across a tutorial that deals with GRASS and archaeological
data, but I recommend you to download at least the spearfish dataset from
the GRASS homepage. If you know German, go to http://grass.itc.it/gdp/handbuch/
and download Markus Neteler's excellent handbook :wink:

Hope this will help you on your rough road to GRASS enlightenment.

Cheers,

Benjamin

On Mon, 3 May 2004 11:11:59 -0500
Chet Walker <chetwalker@mail.utexas.edu> wrote:

Hello.

I am new to GRASS, GIS and UNIX . . . . as you would expect i'm
having learning curve issues. I'm trying to use grass for my
dissertation that entails very basic things like plotting several
different types of archaeological materials as well as a bit more
advanced issues such as plotting and processing geophysical data
(collected with a magnetometer and conductivity meter). I have read
Neteler and Mitasova's book on GRASS and consulted several online
tutorials and faq's. Does any one happen to know of a tutorial or
faq specifically targeted for archaeologists or perhaps know of a
general introduction course on GRASS?

Thank you much,

Chet Walker

________________________________________
Chet Walker 312.857.7629
Research Assistant
Department of African and Amerindian Art
The Art Institute of Chicago

--

I think a wider view of Open Source GIS related packages might be
relevant.

You can look at Open Source data management, & something like PostGIS for
vector data is pretty effective. Compatability with shapefiles is good.
Raster data can be well managed with GRASS, also GEOtiffs & GMT grd files.
The gmtmath command is very like Matlab in it's approach to working with
scalars & arrays, and it has a number of grd file operators for some very
effective & customiseable raster math.

All here know of the power of GRASS for working with gridded spatial
data :slight_smile:

Commonly used libraries like Proj & GDAL are supported by Postgis & GRASS.

A script to make a world file for a GMT map, then use gdal to make a
GEOtiff creates high quality raster images of the data on which to overly
vectors is straightforward.

Alternative GUI front ends like QGIS give very effective data browsing, &
use the above libraries & tools to happily display Postgis, GEOtiff &
shapefiles, etc.

JUMP gives similar functionality to QGIS as a spatial data viewing/querry
tool, but also allows you to visually edit features (both shapefiles &
PostGIS tables) as well as implementing useful topological facilities.

I suggest you look at Postgis as a vector data repository, add the GDAL,
GEOS, PROJ, libraries, etc, then you can use GRASS, QGIS, JUMP, etc as
tools to work with the data as appropriate. Some scripting will let you
export data to GMT format for publication quality cartography as well.

The same data can also be accessed by Mapserver to web enable things with
minimal work, if required at any time.

The QGIS installation guide includes a description of the install of most
of the underlying packages, so makes a good starting point.

The synergies available by using these interoperable OS packages are
pretty powerful, and give more choice & flexibility than any commercial
suite I know of.

Cheers,

   Brent Wood

On Mon, May 03, 2004 at 11:56:07AM -0600, Steve Sherman wrote:

Not off hand, but I am in the same exact situation as you...with the
exception of the dissertation part. I am new to GRASS and Linux and I am
an archaeologist working on setting up a coherent and functioning
system. I'm am anxious to see if anyone has a good answer to you question.

If you are interested, here is a presentation from:

CAA 2004, http://www.caa2004.org
Computer Applications and Quantitative Methods to Archaeology Conference,
Prato, Italy, on 13-17 April 2004
---
A. Bezzi, L. Bezzi, D. Francisci, R. Gietl, 2004:
Open Source applications in Archaeology
http://mpa.itc.it/papers/bezzi2004_prato_OSSarchaeology.pdf

The presentation shows a set of tools auch as
- R-stats
- GPSdrive
- Gimp
- QCAD
- GRASS
- mySQL
- Scanalyze
- Stereo [1]
- Blender
- Povray
- Varkon
- PostgreSQL
- Weka, Salstat, Scilab, and Xgobi
- MapServer + MapLab

[1] new tutorial in preparation

Cheers

Markus
--
Markus Neteler <neteler itc it> http://mpa.itc.it
ITC-irst - Centro per la Ricerca Scientifica e Tecnologica
MPBA - Predictive Models for Biol. & Environ. Data Analysis
Via Sommarive, 18 - 38050 Povo (Trento), Italy