summation: GRASS to ARCVIEW

[Wayne Thogmartin]

Thanks to all who responded regarding the importation of GRASS layers into
ARCVIEW.

Jill Schuler <jschuler at tulip.itc.nrcs.usda.gov> offered the following:
Please see my web site: http://tulip.itc.nrcs.usda.gov/

>From the HOME Page Select 
"Review the documentation on CONVERTING GRASS DATA TO ESRI PRODUCTS."

This will take you to a Document with the following links:
"Generating ArcInfo coverages from GRASS vector files" 
"Converting GRASS Raster Data to ArcInfo Grid"
"Converting GRASS Raster Data to ArcInfo ASCII Grid"

_______________________
Malcolm Williamson <malcolm at cast.uark.edu> offered his lecture notes on the
subject (I'm embarrassed to admit that I was in his class and failed to
remember this procedure):
http://www.cast.uark.edu/uaclasses/iga/intro_grass/Section14.2.vect_Conversi
ons.pdf

_______________________
Another way was suggested by Terry Duell <duell at atea.mat.army.defence.gov.au>

If the ArcView you are trying to import to understands the ArcView ascii
raster file format, then it can be relatively easy (depending on your
hardware-operating system). The ArcView ascii raster file format is
*exactly* the same as the output from r.out.ascii except for the header,
and this can be put in manually using a text editor if necessary (we had
quite a lot of files to transfer and wrote a standalone fortran program to
read the r.out.ascii and write the ArcView format) but this is where the OS
etc comes in...if you have large files you might not get the editor to
handle them.
---------------------------
The ASCII raster file format is a simple format that can be used to
transfer raster data between various applications. It is basically a few
lines of header data followed by lists of cell values. The header data
includes the following keywords and values:

 ncols - number of columns in the data set.
 nrows - number of rows in the data set.
 xllcenter or xllcorner - x-coordinate of the center or lower-left corner
of the lower-left cell.
 yllcenter or yllcorner - y-coordinate of the center or lower-left corner
of the lower-left cell.
 cellsize - cell size for the data set.
 nodata_value - value in the file assigned to cells whose value is unknown.
This keyword and value is optional. The nodata_value defaults to -9999.

For example,

ncols 480
nrows 450
xllcorner 378923
yllcorner 4072345
cellsize 30
nodata_value -32768
43 3 45 7 3 56 2 5 23 65 34 6 32 etc
35 45 65 34 2 6 78 4 38 44 89 3 2 7 etc
etc

The first row of data is at the top of the data set, moving from left to
right. Cell values should be delimited by spaces. No carriage returns are
necessary at the end of each row in the data set. The number of columns in
the header is used to determine when a new row begins. The number of cell
values must be equal to the number of rows times the number of columns. The
ASCII raster file format can only be imported or exported using the Spatial
or 3D Analysts.

_______________________
And, finally, Anthony Burns <agburns at iglou.com> suggested:

Using v.out.arc creates a generate format that you can use the proper
commmand to import a generate file. After importing the vector you will
still have to create an INFO table to load the attribute (the txt file)
data into and then do a joinitem to joint the PAT with the attribute table
you created.  

I generally export GRASS vector data out using v.out.dlg.  I import into
arc using dlgarc.  You still have to create an INFO table to load your
edited dig_cats data into.   It is not complicated but it does require
several steps.



To all I wish to offer my thanks for the assistance,

Wayne Thogmartin                               		wthogma at siu.edu
Upland Wildlife/Habitat Project			618.453.5495 (office)
Cooperative Wildlife Research Laboratory	618.453.6944 (fax)	
Southern Illinois University
Carbondale, IL 62901-6504

"The dwarf standing on the shoulders of a giant sees farther than he who
carries him"