GRASS-to-Arc

[GRASS 4.0]

> Hello,
> 
> I had two vector files and one raster file in GRASS.
> One vector file consisted of a county boundary 
> extracted from TIGER/line files.  The other vector
> file consisted of roads for the county also extracted
> from TIGER/line files.  The raster consisted of 
> buffers around certain cultural features which
> had also originally been extracted from TIGER/line
> files of the same county.
> 
> I did v.out.arc type=line on the two vector
> files containing the county boundary and the roads.
> I did r.poly -l on the cultural features buffer 
> raster and then v.out.arc type=polygon on the 
> resulting polygon vector file.
> 
> I put all of the .lin, .txt, .pol, and .lab files
> created above in the ARC/INFO workspace for the county.
> In ARC, I did generate with lines on the county 
> boundary and the roads covers and generate with polys
> on the cultural features buffer polygon cover.
> I then did projectdefine (projection utm, units meters,
> zone 17, and parameters) and build on all three covers.
> I then did createlabels and build again on the cover of
> cultural features buffers.
> 
> I wrote an aml to create a graphics file with all three
> covers plotted together.  The roads and county boudary
> were in register.  !!!! However, the cover with the 
> buffers of cultural features was shifted to the north
> and perhaps slightly to the east. !!!!
> 
> I killed the covers and repeated the process thinking
> that perhaps I had made a mistake in specifying the zone
> during projectdefine.  This did not correct the problem.
> 
> Then, I thought perhaps there was a problem with v.out.ascii
> type=polygon.  So, I did r.out.ascii on the original buffer
> raster in GRASS, changed the header so that ARC could use 
> the file with asciigrid, and did asciigrid, projectdefine,
> gridpoly, and build with poly.
> 


I have had similar problems with the output of gridpoly...
specifically in arcview.  Althought I could not get the problem
to repeat this afternoon...I too am interested in any
insights....


> When I created a plot with the two line covers and this
> second polygon cover, the buffers of the cultural
> features were shifted southward relative to the roads
> and county boundary. !!!!
> 
> I am truly perplexed because I have previously done this
> latter process with a 7.5-minute quadrangle and the 
> quadrangle polygon cover was in register with the quadrangle
> boundary line cover.
> 
> If anyone has any suggestions as to what the error in either
> of my processes is, I would appreciate hearing from you.
> I am using GRASS 4.1 and ARC/INFO 7.0.
> 
> Thanks in advance.
> 
> Karen Bryant
> 
> 
> 
Keith M. Mitchell
University of Illinois
Urbana, IL 61801
herford at holstein.age.uiuc.edu
grass at holstein.age.uiuc.edu