I am having difficulty loading a points shapefile (1600 records) I generated from ArcGIS as a PointsSpatialDataFrame using the maptools readShapePoints function.
library(maptools)
surveypts <- readShapePoints(system.file("C:/temp/survey.shp", package="maptools")[1]
Error in getinfo.shape(filen) : Error opening SHP file
I've tried numerous re-exports and renames of the dataset, to no avail. I've also tried placing the shapefile in the library's shapefile folder, with the example dataset (see example below).
x <- readShapePoints(system.file("shapes/survey.shp", package="maptools")[1]
No luck there either. I'm quite new to R, but I can follow a manual and google well enough. However, I haven't seen anything to help me. The example point datasets load fine. I figure that I'm missing on some familiarity with R and that I don't know the tricks yet. Any help?
Thanks in advance.
Gericke Cook
USDA-APHIS-PPQ
Error opening SHP file (maptools)
4 messages · gerickes at earthlink.net, Paul Hiemstra, Don MacQueen +1 more
gerickes at earthlink.net schreef:
I am having difficulty loading a points shapefile (1600 records) I generated from ArcGIS as a PointsSpatialDataFrame using the maptools readShapePoints function.
library(maptools)
surveypts <- readShapePoints(system.file("C:/temp/survey.shp", package="maptools")[1]
Error in getinfo.shape(filen) : Error opening SHP file
I've tried numerous re-exports and renames of the dataset, to no avail. I've also tried placing the shapefile in the library's shapefile folder, with the example dataset (see example below).
x <- readShapePoints(system.file("shapes/survey.shp", package="maptools")[1]
No luck there either. I'm quite new to R, but I can follow a manual and google well enough. However, I haven't seen anything to help me. The example point datasets load fine. I figure that I'm missing on some familiarity with R and that I don't know the tricks yet. Any help?
Thanks in advance.
Gericke Cook
USDA-APHIS-PPQ
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
Hi Gericke,
Why do you use system.file? Probably it will look for survey.shp in the
maptools package. Try instead:
surveypts <- readShapePoints("C:/temp/survey.shp")
For these kind of geographic questions, the r-sig-geo mailing list is
maybe a better way to get good answers.
cheers and hth,
Paul
Drs. Paul Hiemstra Department of Physical Geography Faculty of Geosciences University of Utrecht Heidelberglaan 2 P.O. Box 80.115 3508 TC Utrecht Phone: +31302535773 Fax: +31302531145 http://intamap.geo.uu.nl/~paul
The help page for readShapePoints says that the file name that you
supply should not include the extension.
The "system.file" part of the example in the help page is only to use
the example file that came with the package. Since you want to open
your own file you omit the system.file() bit.
Do something like:
readShapePoints( 'C:/path_to_my_file/filename')
Hope this helps.
-Don
At 12:05 PM -0600 3/11/08, gerickes at earthlink.net wrote:
I am having difficulty loading a points shapefile (1600 records) I
generated from ArcGIS as a PointsSpatialDataFrame using the maptools
readShapePoints function.
library(maptools)
surveypts <- readShapePoints(system.file("C:/temp/survey.shp",
package="maptools")[1]
Error in getinfo.shape(filen) : Error opening SHP file
I've tried numerous re-exports and renames of the dataset, to no
avail. I've also tried placing the shapefile in the library's
shapefile folder, with the example dataset (see example below).
x <- readShapePoints(system.file("shapes/survey.shp", package="maptools")[1]
No luck there either. I'm quite new to R, but I can follow a manual
and google well enough. However, I haven't seen anything to help me.
The example point datasets load fine. I figure that I'm missing on
some familiarity with R and that I don't know the tricks yet. Any
help?
Thanks in advance.
Gericke Cook
USDA-APHIS-PPQ
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
--------------------------------- Don MacQueen Lawrence Livermore National Laboratory Livermore, CA, USA 925-423-1062 macq at llnl.gov
Don MacQueen <macq <at> llnl.gov> writes:
The help page for readShapePoints says that the file name that you
supply should not include the extension.
The "system.file" part of the example in the help page is only to use
the example file that came with the package. Since you want to open
your own file you omit the system.file() bit.
Do something like:
readShapePoints( 'C:/path_to_my_file/filename')
You may also - for safety's sake - say: list.files(path="C:/path_to_my_file", pattern="filename") to make sure that at least the minimum three files that make up a "shapefile" are present: filename.dbf, filename.shp, and filename.shx. Note that in Windows you can also use the file chooser, by saying: readShapePoints(file.choose()) which will let you navigate to, and "see" the file name for yourself. Roger PS. As Paul mentioned, the R-sig-geo list is well suited to this kind of question.
Hope this helps. -Don