My copy of the Spatial Analyst (Arc rasters) just arrived, so I need to
experiment with raster GRASS to Arc conversions...
Any suggestions?
GRASS raster files can be imported into ARC as image files using IMAGEGRID.
They can also be imported as ASCII files, put them out of GRASS with
r.out.ascii and bring into ARC with ASCIIGRID. You do have to edit the
ASCII file header before importing into ARC. Just use a text editor and
change the header into GRID header format-
Pat Luther
-Scott Grover
scottg@horne.com
Pat Scarbrough Luther "Your dream is the gift of
AEgis Services Corporation your own soul. But if it's
P.O. Box 160 promise is to be fulfilled,
Clinton, TN 37717 you must turn your eyes from
Phone 423.457.8242 the world of men, and dare
FAX 423.457.8620 to fly among the stars....
Internet pluther@usit.net After all, we are born with
wings". Robert Sexton
Another alternative, if you just want to use the GRASS raster files in
ArcView and don't have access to ArcInfo, is to uncompress the GRASS cell
file and bring it into ArcView as a .bil format. This works fine for 8-bit
raster files (category values 0-255). You can also build a .hdr file with
georeferencing info with a text editor. I can send you a sample if you like.
It's one that came with some SPOT imagery. I just edited that .hdr file and
changed the rows, columns, cell size and coordinate of the upper left corner.
Hello all,
I have classified a set of 20 landscapes using Grass4.1 for linux, using
i.class followed by i.maxlike. After getting the classified landscapes, I
have been trying to see how the landscapes look in terms of various
landscape parameters.. patch sizes, shapes, landscape connectivity, etc.
I want to now check how dependent the results of this landscape analysis
are on the input training sets I have provided for i.class. What I
thought is, I can play around with the signature files generated by
i.class, change the means/std.deviations/covariances slightly, reclassify
the landscapes with these, and then check how my landscape parameters
look - this will give me an idea of how robust these parameters of
landsacpe structure are.
So - for this I need to know what each of the numbers in the signature
files mean.. I have figured out part of it but need help on the rest.
Also, any suggestions on the usefulness or otherwise of what I am
planning to do would be appreciated.
I am enclosing a signature file below.. my imagery has 4 bands
# #eucalyptus
16 - this is the number of pixels which I have marked
42.812500 23.875000 25.687500 61.187500 - mean intensities in Bands 1,2,3,4
0.429167 | these 3 lines must be the covariances
-0.091667 0.383333 | between bands - I need to know which
0.270833 0.158333 0.629167 | one is for which pair of bands
-0.095833 -0.308333 -0.204167 0.829167 - this is the std.devns for bands 1234
I would really appreciate help on this.
Thanks a lot
Harini
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| Harini Nagendra E-MAIL : harini@ces.iisc.ernet.in |
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| Indian Institute of Science FAX : 91 80 334 1683 |
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