[R] RArcInfo: can't read arc coverage

Scott Waichler scott.waichler at pnl.gov
Thu Nov 21 01:52:33 CET 2002

I am having trouble using get.arcdata() in RArcInfo.  X and y coordinates
are not what they should be.  Can anyone suggest what might be wrong?
I am using RArcInfo 0.4-1.

Here is the metadata of my coverage, using describe in Arc:

Arc: describe stdir_6
                Description of SINGLE precision coverage stdir_6
                                FEATURE CLASSES
                                    Number of  Attribute     Spatial
Feature Class          Subclass     Features   data (bytes)  Index?   Topology?
-------------          --------     ---------  ------------  -------  ---------
ARCS                                      815        60
                               SECONDARY FEATURES
Tics                                        4
Arc Segments                             2208
Fuzzy   =                 5.000 N          Dangle  =                 0.000 N
                               COVERAGE BOUNDARY
Xmin =               532929.625            Xmax =               582929.625
Ymin =               116877.102            Ymax =               142877.109
The coverage has not been Edited since the last BUILD or CLEAN.
                          COORDINATE SYSTEM DESCRIPTION
Projection           STATEPLANE
Zone                       5626
Datum                     NAD83
Units                    METERS             Spheroid                GRS1980

When I execute the following and do a plotarc() or look at the lists containing the
x and y coordinates, all I see is garbage--the coordinates are all infinitesimal or
extremely large numbers (e.g., -8.928678e-31, 9.784083e+15).  

stdir6 <- get.arcdata("/projects/cold_creek/grid/watershed/dhsvm_200m", "stdir_6", filename="arc.adf")
plotarc(stdir6, new=T)

On the advice of Virgilio, I converted my Arc v.8x coverage into v.7x, but
that made no difference (ESRI documenation says they should be the same anyway).  

Scott Waichler
Pacific Northwest National Lab
Richland, Washington, USA
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at stat.math.ethz.ch

More information about the R-help mailing list